Patent Application
20250176418
Solar cells are electrical devices that convert light into electricity. Silicon solar cells convert light, e.g., with a wavelength greater than about 300 nanometers (“nm”) and less than about 1100 nm, to electricity. However, the conversion efficiency of silicon solar cells typically decreases as the wavelength of light decreases from 1100 nm. Additionally, silicon solar cells may be unable to convert wavelengths of light above about 1100 nm to electricity because such wavelengths of light lack the energy required to overcome the band gap of silicon.
A tandem solar cell has two individual solar cells, typically stacked on top of one another. In many examples, the bottom cell is a silicon solar cell, and the top cell is made of a different material. The top cell may have a higher band gap than the silicon solar cell. Accordingly, the top cell may be capable of efficiently converting shorter wavelengths of light to electricity. The top cell may be transparent to longer wavelengths of light, which may allow the underlying silicon solar cell to absorb and convert such longer wavelengths of light to electricity.
Optical losses at the interface between the top cell and the bottom cell and recombination losses in any of the layers of the top cell or bottom cell may result in a lower efficiency cell. Additionally, tandem solar cells may be difficult to manufacture.
The present disclosure describes tandem silicon-perovskite solar modules and manufacturing methods thereof. A tandem silicon-perovskite solar module as described herein may have a bottom silicon solar cell and a top perovskite solar cell. The perovskite solar cell may have a higher bandgap than the silicon solar cell. For example, the perovskite solar cell may have a bandgap of about 1.7 electron volts (“eV”) and the silicon solar cell may have a bandgap of about 1.1 eV. Accordingly, the perovskite solar cell may be capable of efficiently converting shorter wavelengths of light to electricity. The perovskite solar cell may be transparent to longer wavelengths of light, which may allow the underlying silicon solar cell to absorb and convert such longer wavelengths of light to electricity. Together, the perovskite solar cell and the silicon solar cell may be capable of efficiently converting a wider spectrum of light to electricity than a single solar cell (i.e., there may be less thermalization loss in a tandem cell than in a single cell solar module resulting in a higher full spectrum efficiency). The addition of perovskite solar cells can improve the resultant solar modules by decreasing cost, improving performance per weight of the module, improve overall performance of the module, and the like.
The silicon solar cell may be a monocrystalline or multi-crystalline silicon solar cell. The silicon solar cell may be a component of a conventional solar panel. The solar panel may have a back sheet on which the silicon solar cell is disposed. An encapsulant may cover the top of the silicon solar cell to prevent it from being exposed to dust and moisture. The solar panel may also have a top glass sheet that provides additional protection to the silicon solar cell.
The perovskite solar cell may be deposited on the bottom surface of the top glass sheet. This may differ from the construction of conventional tandem solar modules in which a perovskite cell is merely disposed on top of a silicon wafer. Depositing the perovskite solar cell on the bottom surface of the top glass sheet may allow manufacturers to incorporate perovskite solar cells into their conventional silicon solar panels with no re-tooling or process changes. Instead, such manufacturers can merely substitute a conventional glass sheet with the perovskite glass sheet. This disclosure may refer to the perovskite glass sheet as “active glass.”
The perovskite solar cell includes a first transparent conducting oxide (“TCO”) layer deposited on the top glass sheet, a hole transport layer (“HTL”) deposited on the first TCO layer, a perovskite layer deposited on the HTL, an electron transport layer (“ETL”) deposited on the perovskite layer, and a second TCO layer deposited on the ETL. The second TCO layer includes IZTO (e.g., the layer can be composed entirely of IZTO). The first and second TCO layers are electrical terminals for the perovskite solar cell. The ETL and HTL facilitate electron and hole transport, respectively, while inhibiting hole and electron transport, respectively. The perovskite layer absorbs light to generates charge carriers, which results in a voltage and current flow across the terminals of the perovskite solar cell.
In certain examples, the perovskite solar cell and the silicon solar cell are electrically isolated from each other, and each cell may have its own terminals. That is, the tandem solar module may be a 4-terminal module. The perovskite solar cell and the silicon solar cell can be connected in series or parallel by connecting the terminals in the appropriate manner. In the case of a series connection, the perovskite solar cell and the silicon solar cell may be current-matched. In the case of a parallel connection, the perovskite solar cell and the silicon solar cell may be voltage-matched.
The present disclosure also describes methods for fabricating the active glass described above. An active glass can include a perovskite layer formed by applying the perovskite precursors individually, and subsequently annealing the precursors. A metallic lead layer can be deposited, followed by an inorganic halide layer (e.g., methylammonium iodide/formamidinium iodide), followed by a halide (e.g., iodine). By applying the various precursors in such a fashion, the same deposition equipment can be used for multiple layers, decreasing complexity and cost, and enabling high throughput manufacturing processes to be used. Additionally, the various ratios of the precursors can be tightly controlled, resulting in higher quality films. Also, a variety of different precursors for each layer can be deposited to improve film quality. For example, lead acetate can be applied on the lead layer to improve integration of the organic halides and halides into the lead layer. Similarly, different halides can be introduced to improve grain growth and other film properties. The perovskite precursors can be applied by a variety of techniques, including ultrasonic-spray on, blade-coating, slot-die coating and physical vapor deposition. Ultrasonic spray-on, when combined with multiple ‘shower head’ type nozzles, may provide for even and controlled application of precursors, which in turn can generate high quality films substantially free of defects.
The present disclosure also provides for methods of depositing the first and second TCO layers onto the perovskite solar cell, including at least one IZTO layer. The TCO layers may be deposited on the perovskite solar cell via physical vapor deposition (PVD). The PVD of the TCO layers may occur in an inline manufacturing process. In certain examples, the inline manufacturing process includes multiple process chambers where deposition of selected target materials onto the perovskite solar cell occurs. The multiple process chambers can include a single conveyor belt which transports the perovskite solar cell throughout the multiple process chambers. The inline manufacturing process can limit the exposure of the perovskite solar cell to direct exposure of the deposition process and ultraviolet (UV) radiation and ultimately reduce the number of defects formed in the ETL and perovskite layers due to the TCO deposition process.
The present disclosure also provides for method of connecting the layers of a tandem solar module. The silicon and perovskite layers of a tandem module can be connected in different ways depending on the type of silicon solar cells used. The different methods of connecting can provide optimal performance for the various types of silicon solar cells. The present disclosure also provides a method of preparing a tandem solar module where the voltage output of the top perovskite and bottom silicon modules are matched. The method can include laser scribing a perovskite layer to form the perovskite solar cells. The laser scribing can be different for different bottom solar modules, as differences in the voltage output of various bottom modules can be accounted for in the generation of the perovskite solar cells. This level of control can improve efficiency by more closely matching the voltages between the modules to decrease wasted voltage. Additionally, a wider range of bottom modules can be used due to the flexibility offered by custom perovskite solar cell sizes.
In general, in a first aspect, the disclosure features a method for manufacturing a solar module, including: providing a first substrate comprising a substrate layer supporting a first electrically conducting layer and a hole transport layer on a first side of the glass layer; applying a perovskite precursor to the first side of the substrate; annealing the perovskite precursor to form a perovskite layer; applying an electron transport layer to the perovskite layer; and forming a second electrically conducting layer on the electron transport layer, the second electrically conducting layer being a transparent layer including IZTO.
In general, in a second aspect, the disclosure features a solar module, including: a substrate; a first electrically conducting layer supported on the substrate layer on a first side of the substrate; a hole transport layer supported on the first electrically conducting layer; a perovskite layer supported on the hole transport layer; an electron transport layer supported on the perovskite layer; and a second electrically conducting layer supported on the electron transport layer, the second electrically conducting layer being a transparent layer including IZTO.
Other aspects of the present disclosure provide methods of fabricating and manufacturing the devices and components described above and elsewhere in this disclosure.
Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
In the drawings, like symbols denote like elements.
While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.
Whenever the term “at least,” “greater than,” or “greater than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at least,” “greater than” or “greater than or equal to” applies to each of the numerical values in that series of numerical values. For example, greater than or equal to 1, 2, or 3 is equivalent to greater than or equal to 1, greater than or equal to 2, or greater than or equal to 3.
Whenever the term “no more than,” “less than,” or “less than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “no more than,” “less than,” or “less than or equal to” applies to each of the numerical values in that series of numerical values. For example, less than or equal to 3, 2, or 1 is equivalent to less than or equal to 3, less than or equal to 2, or less than or equal to 1.
The term “solar cell,” as used herein, generally refers to a device that uses the photovoltaic effect to generate electricity from light.
The term “tandem,” as used herein, refers to a solar module with two solar cells that are stacked on top of one another.
The term “4-terminal,” as used herein, refers to a tandem solar module in which the top and bottom solar cells each have two accessible terminals.
The term “perovskite,” as used herein, generally refers to a material with a crystal structure similar to calcium titanium oxide and one that is suitable for use in perovskite solar cells. The general chemical forum for a perovskite material is ABX3. Examples of perovskite materials include methylammonium lead trihalide (i.e., CH3NH3PbX3, where X is a halogen ion such as iodide, bromide, or chloride) and formamidinium lead trihalide (i.e., H2NCHNH2PbX3, where X is a halogen ion such as iodide, bromide, or chloride).
The term “monocrystalline silicon,” as used herein, generally refers to silicon with a crystal structure that is homogenous throughout the material. The orientation, lattice parameters, and electronic properties of monocrystalline silicon may be constant throughout the material. Monocrystalline silicon may be doped with phosphorus or boron, for example, to make the silicon n-type or p-type respectively.
The term “polycrystalline silicon,” as used herein, generally refers to silicon with an irregular grain structure.
The terms “passivated emitter rear contact (PERC) solar cell,” as used herein, generally refer to a solar cell with an extra dielectric layer on the rear-side of the solar cell. This dielectric layer may act to reflect unabsorbed light back to the solar cell for a second absorption attempt, and may additionally passivate the rear surface of the solar cell, increasing the solar cell's efficiency.
The terms “heterojunction with intrinsic thin layer solar cell (HIT) solar cell,” as used herein, generally refer to a solar cell that is composed of a monocrystalline silicon wafer surrounded by ultra-thin amorphous silicon layers. One amorphous silicon layer may be n-doped, while the other may be p-doped.
The terms “an interdigitated back contact cell (IBC),” as used herein, generally refer to a solar cell comprising two or more electrical contacts disposed on the back side of the solar cell (e.g., on the side opposite the incident light). The two or more electrical contacts can be disposed adjacent to alternatingly n- and p-doped regions of the solar cell. An IBC may comprise a high-quality absorber material configured to permit carrier migration over a long distance.
The terms “bandgap” and “band gap,” as used herein, generally refer to the energy difference between the top of the valence band and the bottom of the conduction band in a material.
The term “electron transport layer” (“ETL”), as used herein, generally refers to a layer of material that facilitates electron transport and inhibits hole transport in a solar cell. Electrons may be majority carriers in an ETL, while holes may be minority carriers. An ETL may be made of one or more n-type layers. The one or more n-type layers may include an n-type exciton blocking layer. The n-type exciton blocking layer may have a wider band gap than the photoactive layer of the solar cell (e.g., the perovskite layer) but a conduction band that is closely matched to the conduction band of the photoactive layer. This may allow electrons to easily pass from the photoactive layer to the ETL.
The n-type layer may be a metal oxide, a metal sulfide, a metal selenide, a metal telluride, amorphous silicon, an n-type group IV semiconductor (e.g., germanium), an n-type group III-V semiconductor (e.g., gallium arsenide), an n-type group II-VI semiconductor (e.g., cadmium selenide), an n-type group I-VII semiconductor (e.g., cuprous chloride), an n-type group IV-VI semiconductor (e.g., lead selenide), an n-type group V-VI semiconductor (e.g., bismuth telluride), or an n-type group II-V semiconductor (e.g., cadmium arsenide), any of which may be doped (e.g., with phosphorus, arsenic, or antimony) or undoped. The metal oxide may be an oxide of titanium, tin, zinc, niobium, tantalum, tungsten, indium, gallium, neodymium, palladium, cadmium, or an oxide of a mixture of two or more of such metals. The metal sulfide may be a sulfide of cadmium, tin, copper, zinc or a sulfide of a mixture of two or more of such metals. The metal selenide may be a selenide of cadmium, zinc, indium, gallium or a selenide of a mixture of two or more of such metals. The metal telluride may be a telluride of cadmium, zinc, cadmium or tin, or a telluride of a mixture of two or more of said metals. Other n-type materials may alternatively be employed, including organic and polymeric electron transporting materials, and electrolytes. Suitable examples include, but are not limited to, a fullerene or a fullerene derivative (e.g., phenyl-C61-butyric acid methyl ester, C60, etc.) or an organic electron transporting material comprising perylene or a derivative thereof.
The term “hole transport layer” (“HTL”), as used herein, generally refers to a layer of material that facilitates hole transport and inhibits electron transport in a solar cell. Holes may be majority carriers in an HTL, while electronics may be minority carriers. An HTL may be made of one or more p-type layers. The one or more p-type layers may include a p-type exciton blocking layer. The p-type exciton blocking layer may have a valence band that is closely matched to the valence band of the photoactive layer (e.g., the perovskite layer) of the solar cell. This may allow holes to easily pass from the photoactive layer to the HTL.
The p-type layer may be made of a molecular hole transporter, a polymeric hole transporter, or a copolymer hole transporter. For example, the p-type layer may be one or more of the following: nickel oxide, thiophenyl, phenelenyl, dithiazolyl, benzothiazolyl, diketopyrrolopyrrolyl, ethoxydithiophenyl, amino, triphenyl amino, carbozolyl, ethylene dioxythiophenyl, dioxythiophenyl, or fluorenyl. Additionally or alternatively, the p-type may comprise spiro-OMeTAD (2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene)), P3HT (poly(3-hexylthiophene)), PCPDTBT (Poly[2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b: 3,4-b′]dithiophene-2,6-diyl]]), PVK (poly(N-vinylcarbazole)), poly(3-hexylthiophene), poly[N,N-diphenyl-4-methoxyphenylamine-4′,4″-diyl], sexithiophene, 9,10-bis(phenylethynyl) anthracene, 5,12-bis(phenylethynyl) naphthacene, diindenoperylene, 9,10-diphenylanthracene, PEDOT-TMA, PEDOT:PSS, perfluoropentacene, perylene, poly(phenylene oxide), poly(p-phenylene sulfide), quinacridone, rubrene, 4-(dimethylamino)benzaldehyde diphenylhydrazone, 4-(dibenzylamino)benzaldehyde-N,Ndiphenylhydrazone or phthalocyanines.
Though described herein with respect to silicon-perovskite tandem solar modules, the methods and devices of the present disclosure may be used with any combination of solar cells with a perovskite layer. For example, the tandem solar module can be a tandem CdTe-perovskite solar module. In another example, the tandem solar module can be a dye sensitized solar cell-perovskite solar cell module.
The top glass sheet 105 may protect underlying layers of the solar module 100 from dust and moisture. The top glass sheet 105, and the solar module 100 as a whole, may have a form factor that corresponds to a conventional silicon solar panel. For example, the top glass sheet 105 may have a form factor that corresponds to a 32-cell, 36-cell, 48-cell, 60-cell, 72-cell, 96-cell, or 144-cell silicon solar panel. The top glass sheet 105 may have a thickness of at least about 2.0 millimeters (mm), 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, or more. The top glass sheet 105 may have a thickness of at most about 5.0 mm, 4.5 mm, 4.0 mm, 3.5 mm, 3.0 mm, 2.5 mm, 2.0 mm, or less. The top glass sheet 105 may be transparent so as to allow light to access the underlying solar cells. In some cases, the top surface of the top glass sheet 105 may be covered with polydimethylsiloxane (“PDMS”) (e.g., 1:10 alumina PDMS, textured 1:50 alumina PDMS, or textured PDMS), which may improve light trapping and refractive index matching. In some cases, the top surface of the top glass sheet 105 may be covered with an anti-reflective coating. In some cases, the bottom surface of the top glass sheet 105 may be textured in order to enable more light scattering back into the perovskite layer 120.
Together, the first TCO layer 110, the HTL 115, the perovskite layer 120, the ETL 125, and the second TCO layer 130 may form a perovskite solar cell. The perovskite solar cell may be disposed on the bottom surface of the top glass sheet 105 through fabrication methods that are described in reference to
In some examples, the first TCO layer 110 is disposed directly on the top glass sheet 105. Depositing the first TCO layer 110 directly on the top glass sheet 105 may prevent damage to the HTL 115 and the perovskite layer 120. The first TCO layer 110 may serve as the positive terminal or cathode of the perovskite solar cell. The first TCO layer 110 may have a thickness of at least about 100 nanometers (nm), 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 micrometer, or more. The first TCO layer 110 may have a thickness of at most about 1 micrometer, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm, or less. The first TCO layer 110 may be made of indium tin oxide (ITO). The first TCO layer 110 may be made of doped ITO. The TCO layer may have a resistance of at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or more Ohm/square meter. The TCO layer may have a resistance of at most about 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, or less Ohm/square meter
The HTL 115 is disposed on the TCO layer 110. The HTL 115 facilitates the transport of holes from the perovskite layer 120 to the first TCO layer 110. In certain examples, the HTL layer facilitates hole transport without significantly compromising transparency and conductivity. In contrast, in certain cases, the HTL 115 may inhibit electron transport. In some examples, the HTL 115 is made of one or more nickel oxide layers. In certain examples, the HTL 115 is made of another appropriate p-type material described in this disclosure. The HTL 115 may have a thickness of about 5 nm or more (e.g., 10 nm or more, 20 nm or more, 50 nm or more, 100 nm or more, 200 nm or more, 300 nm or more, 400 nm or more, 500 nm or more, 600 nm or more, 700 nm or more, 800 nm or more, 900 nm or more, 1 micrometer or more). The HTL 115 may have a thickness of about 1 micrometer or less (e.g., 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less).
The perovskite layer 120 is disposed on the HTL 115. The perovskite layer 120 is the photoactive layer of the perovskite solar cell. That is, the perovskite layer 120 absorbs light in a certain wavelength range and generate holes and electrons that subsequently diffuse into the HTL 115 and the ETL 125, respectively. In some examples, the perovskite layer 120 is made of methylammonium lead triiodide, methylammonium lead tribromide, methylammonium lead trichloride, or any combination thereof. In other embodiments, the perovskite layer 120 is made of formamidinium lead triiodide, formamidinium lead tribromide, formamidinium lead trichloride, or any combination thereof. In certain examples, the perovskite layer 120 is made of cesium lead triiodide, cesium lead tribromide, cesium lead trichloride, or any combination thereof. The perovskite layer may be a triple cation perovskite material with formamidinium, methylammonium, and cesium cations in different ratios. Incorporating cesium into the perovskite lattice provides enhanced thermodynamic stability. The bandgap of the perovskite layer 120 may be varied by adjusting the halide content of the methylammonium lead trihalide or formamidinium lead trihalide. The perovskite layer 120 may have a thickness of about 250 nm or more (e.g., 300 nm or more, 400 nm or more, 500 nm or more, 600 nm or more, 700 nm or more, 800 nm or more, 900 nm or more, 1 micrometer or more, 1.25 micrometers or more, 1.5 micrometers or more, 1.75 micrometers or more, 2 micrometers, or more). The perovskite layer 120 may have a thickness of about 4 micrometers or less (e.g., 3 microns or less, 2 microns or less, 1.75 micrometers or less, 1.5 micrometers or less, 1.25 micrometers or less, 1 micrometer or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less).
The ETL 125 is disposed on the perovskite layer 120. The ETL 125 facilitates the transport of electrons from the perovskite layer 120 to the second TCO layer 130 and can do so without significantly compromising transparency and conductivity. In contrast, in certain examples, the ETL 115 may inhibit electron transport. In some cases, the ETL 125 is made of phenyl-C61-butyric acid methyl ester (“PCBM”). In certain examples, the ETL 125 is made of another appropriate n-type material described in this disclosure (e.g., C60). The ETL 115 may have a thickness of about 10 nm or more (e.g., 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 200 nm or more, 300 nm or more, 400 nm or more, 500 nm or more). The ETL 115 may have a thickness of about 800 nm or less (e.g., 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm, 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less). The interface between the ETL and the perovskite layer can be important to the performance of the perovskite layer. The surface of the perovskite layer can be hydrophilic to enable good coverage of a hydrophilic ETL (e.g., PCBM). The combination of environment (e.g., low humidity, e.g., <15%, low temperature, e.g., from 18 to 24 degrees Celsius) and solvent compatibility may impact the quality of the perovskite layer-ETL connection.
The second TCO layer 130 is disposed on the ETL 125. The second TCO layer 130 serves as the negative terminal or anode of the perovskite solar cell. The second TCO layer 130 may have a thickness of about 100 nm or more (e.g., 200 nm or more, 300 nm or more, 400 nm or more, 500 nm or more, 600 nm or more, 700 nm or more, 800 nm or more, 900 nm or more, 1 micrometer or more). In some examples, the second TCO layer 130 has a thickness of about 1 micrometer or less (e.g., 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less).
The second TCO layer 110 includes indium zinc-tin oxide (IZTO), e.g., amorphous IZTO (a-IZTO). For example, the second TCO layer 110 can be composed entirely of IZTO. IZTO can have high light transmission at certain wavelengths, e.g., compared to ITO. For example, an IZTO TCO layer can have transmission at 700 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light. The IZTO TCO layer can have transmission at 800 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light. IZTO TCO layer can have transmission at 900 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light.
The IZTO TCO layer can have such light transmission properties while having relative low sheet resistivity. For example, an IZTO TCO layer can have a transmission at 700 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light and the second electrically conducting layer has a mean resistivity of 35 Ohm/sq. or less (e.g., 34 Ohm/sq. or less, 32 Ohm/sq. or less, 30 Ohm/sq. or less, 28 Ohm/sq. or less, 26 Ohm/sq. or less, 24 Ohm/sq. or less, e.g., 20 Ohm/sq. or more, 22 Ohm/sq. or more, 24 Ohm/sq. or more, 25 Ohm/sq. or more).
As described further below, IZTO layers can be deposited at lower temperatures that other TCO materials, such as ITO. ITO films are typically deposited onto heated substrates (e.g., to a temperature >200 degrees Celsius, with 300° C.-350° C. being common). Moreover, after deposition, annealing is used to improve conductivity and optical properties (e.g., transmission). Anneal temperatures can be 300° C.-350° C. Many perovskite materials are susceptible to elevated temperatures, e.g., they can degrade at temperatures of 100° C. or more (e.g., 120° C. or more). In contrast, IZTO can exhibit good film properties (e.g., low sheet resistance and/or high light transmission transmission) when deposited at temperatures of 120° C. or less (e.g., 100° C. or less, 80° C. or less, 60° C. or less, 50° C. or less, 40° C. or less, 30° C. or less, such as at room temperature).
IZTO is typically an amorphous structure as-deposited. In contrast, ITO is often a crystalline structure with vertical grain boundaries. These vertical grain boundaries may provide an easier pathway for water to diffuse through which can affect the perovskite negatively (e.g., H2O leads to degradation of the perovskite structure). Amorphous IZTO does not have grain boundaries, hence can exhibit higher resistance to H2O diffusion compared to crystalline TCO's, such as ITO.
The encapsulant 135 is disposed between the second TCO layer 130 of the perovskite solar cell and the silicon solar cell 140. The encapsulant 135 may reduce exposure of the perovskite solar cell and the silicon solar cell 140 to dust and moisture. The encapsulant 135 may electrically isolate the perovskite solar cell from the silicon solar cell 140. The encapsulant 135 may have a high refractive index (e.g., a refractive index greater than 1.4) that matches the refractive index of the TCO layer 130 of the perovskite solar cell and the top silicon nitride or TCO layer of the silicon solar cell 140. Thus of a high refractive index material may decrease transmission losses between the TCO layer 130, encapsulant 135, and silicon solar cell 140, resulting in improved current density of the solar module 100. The user of a high refractive index material may also improve light trapping. The high refractive index material may be ethylene-vinyl-acetate (“EVA”), thermal plastic polyolefin (“TPO”), PDMS, silicone, paraffin, or the like. Example 1 and
In general, the silicon solar cell 140 may be a p-type silicon solar cell with a p-type substrate covered by a thin n-type layer (“emitter”), or it may be an n-type silicon solar cell with an n-type substrate covered by a thin p-type emitter. The silicon solar cell 140 may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, a PERC silicon solar cell, a HIT silicon solar cell, an interdigitated back contact cell (IBC), or the like.
The silicon solar cell 140 may have a back sheet 145. The back sheet 145 may seal the solar module 100 to prevent moisture ingress. In some cases, the back sheet 145 may be a glass sheet with a top surface and a bottom surface. The top surface of the glass sheet may have a highly reflective coating or textured surface in to further increase light trapping or scattering back in the silicon solar cell 140 and the perovskite layer 120. The glass sheet may be transparent. The glass sheet may be substantially transparent. The transparency of the glass sheet may facilitate bifacial operation of the solar cell. For example, the solar cell can be configured to absorb light from both sides of the solar cell.
The perovskite solar cell and the silicon solar cell 140 may be electrically isolated from each other, and each cell may have its own terminals. That is, the tandem solar module may be a 4-terminal module. The perovskite solar cell and the silicon solar cell 140 may be connected in series or parallel by connecting the terminals in the appropriate manner. In the case of a series connection, the perovskite solar cell and the silicon solar cell may be current-matched. In the case of a parallel connection, the perovskite solar cell and the silicon solar cell may be voltage-matched. Laser scribing can be used to achieve the current matching or voltage matching, e.g., by connecting individually scribed perovskite solar cells in series or parallel to achieve a desired voltage or current. Parallel or series connection between the perovskite solar cells and the silicon solar cell can be made via busbars/electrodes before module lamination. This allows rapid and easy introduction into any existing silicon manufacturing process.
The solar module 100 may have a power conversion efficiency of at least about 25%, 26%, 27%, 28%, 29%, 30%, or more.
The first TCO layer 110 and the second TCO layer 130 (including IZTO) may serve as electrical contacts for the perovskite solar cell while maintaining the semi-transparency of the perovskite solar cell so that the underlying silicon solar cell 140 can still absorb light. A physical vapor deposition (PVD) process may be used to fabricate the first TCO layer 110 and the second TCO layer 130. The PVD process may be tuned such that the resulting TCO layer is transparent to light (e.g., light with a wavelength from 300 nanometers (“nm”) to 1200 nm for the second TCO layer). For example, a plasma pressure and deposition power of the PVD process may be tuned accordingly. For example, the argon pressure can be at about 1 to about 5 millitorr, and the deposition power can be about 20 watts to about 1,000 watts. Additionally, the thickness of the first TCO layer 110 and the second TCO layers 130 can be set to achieve such transparency. Such transparency may allow the underlying silicon solar cell 140 to receive as much light as possible at wavelengths at which it is absorbed that was not already absorbed by the perovskite layer 120, which typically absorbs light with a wavelength from 300 nm to 700 nm.
In fabricating the second TCO layer 130, the PVD process may tend to create defects in the ETL 125 and the perovskite layer 120 due the ultraviolet light and argon/oxygen ions generated by the plasma during the process. Such defects may degrade the performance of the perovskite layer 120 as an electron-hole pair absorber. For example, the perovskite layer 120 may exhibit a lower open circuit voltage and a lower fill factor as the result of such defects. It may be beneficial to minimize the creation of such defects.
In general, either ceramic (e.g., composed of IZTO) or metal targets (e.g., composed of indium tin zinc) can be used for the plasma PVD deposition process. Targets can be planar or rotary (e.g., cylindrical). A combination of argon or other inert gas (or inert gas mixture) and oxygen can be used for the plasma. Generally, the gas flow rates can vary depending on the plasma deposition system and target size. In some examples, the flow rate of Ar during deposition is 500 sccm and 5,000 sccm (e.g., 750 sccm or more, 900 sccm or more, 1,000 sccm or more, 1,250 sccm or more, 1,500 sccm or more, 1,600 sccm or more, 1,750 sccm or more, 2,000 sccm or more, such as 3,000 sccm or less, 2,500 sccm or less, 2250 sccm or less, 2,000 sccm or less, 1,750 sccm or less, 1,500 sccm or less). The flow rate of 02 can be 100 sccm or more (e.g., 200 sccm or more, 300 sccm or more, 400 sccm or more, 500 sccm or more, 600 sccm or more, 750 sccm or more, 1,000 sccm or more, such as 2,000 sccm or less, 1,750 sccm or less, 1,500 sccm or less, 1,250 sccm or less, 1,000 sccm or less). The flow rate of oxygen can be lower than the flow rate of the inert gas.
Target size can be 10 cm or more (in at least one dimension) (e.g., 20 cm or more, 30 cm or more, 50 cm or more, 70 cm or more 80 cm or more, 90 cm or more, 1 m or more, 1.5 m or more, 2 m or more, such as 3 m or less, 2 m or less, 1.5 m or less). Planar targets can have a surface area of 200 cm2 or more (e.g., 300 cm2 or more, 400 cm2 or more, 500 cm2 or more, 750 cm2 or more, 1,000 cm2 or more, 1,500 cm2 or more, 2,000 cm2 or more, 3,000 cm2 or more, such as 5,000 cm2 or less, 4,000 cm2 or less, 3,000 cm2 or less).
Generally, the power level for the plasma PVD process can be varied based depending on the implementation. For rotary targets, power can be characterized as power per meter of target length. In some examples, the power per meter of target during the plasma PVD process is 1 kW per meter (“kW/m”) or more (e.g., 2 kW/m or more, 3 kW/m or more, 4 kW/m or more, 5 kW/m or more, 6 kW/m or more, 7 kW/m or more, 8 kW/m or more, 9 kW/m or more, 10 kW/m or more, such as 25 kW/m or less, 20 kW/m or less, 15 kW/m or less, 12 kW/m or less, 10 kW/m or less, 9 kW/m or less, 8 kW/m or less). For planar targets, the power level can be characterized as power per cm2. In some examples, the power per square centimeter (“W/cm2”) of target during the plasma PVD process is 0.5 W/cm2 or more (e.g., 0.6 W/cm2 or more, 0.8 W/cm2 or more, 1.0 W/cm2 or more, 1.25 W/cm2 or more, 1.5 W/cm2 or more, 1.75 W/cm2 or more, 2 W/cm2 or more, 2.5 W/cm2 or more, 3 W/cm2 or more, such as 5 W/cm2 or less, e.g., 4 W/cm2 or less, 3 W/cm2 or less, 2.5 W/cm2 or less).
In some examples, the damage described above can be reduced (e.g., minimized) by first creating a buffer layer of IZTO on the ETL 125 through a low-power PVD process. The power during the low-power plasma PVD process can be 3 kW per meter or less (e.g., 2.75 kW/m or less, 2.5 kW/m or less, 2 kW/m or less, 1.5 kW/m or less, 1 kW/m or less, such as 0.1 kW/m or more, 0.2 kW/m or more, 0.3 kW/m or more, 0.4 kW/m or more, 0.5 kW/m or more, 0.6 kW/m or more, 0.8 kW/m or more, 1 kW/m or more). The power during the low-power plasma PVD process for a planar target may be at most 0.60 W/cm2 or less (e.g., 0.55 W/cm2 or less, 0.50 W/cm2 or less, 0.45 W/cm2 or less, 0.40 W/cm2 or less, 0.35 W/cm2 or less, 0.30 W/cm2 or less, 0.25 W/cm2 or less, 0.20 W/cm2 or less, 0.15 W/cm2 or less, 0.10 W/cm2 or less, 0.05 W/cm2 or less). Depending on the size of the panel, the low-power PVD process can be at a total power of about 10 Watts or more (e.g., 20 Watts or more, 30 Watts or more, 40 Watts or more, 50 Watts or more, 60 Watts or more, 70 Watts or more, 80 Watts or more, 90 Watts or more, 100 Watts or more, 110 Watts or more, 120 Watts or more, 130 Watts or more, 140 Watts or more, 150 Watts or more). The total power can be about 200 Watts or less (e.g., 180 Watts or less, 160 Watts or less, 150 Watts or less, 140 Watts or less, 130 Watts or less, 120 Watts or less, 110 Watts or less, 100 Watts or less, 90 Watts or less, 80 Watts or less, 70 Watts or less, 60 Watts or less, 50 Watts or less).
The buffer layer may be at least about 5 or more nm (e.g., 10 or more nm, 15 or more nm, 20 or more nm, 25 or more nm, 30 or more nm, 35 or more nm, 40 or more nm, 45 or more nm, 50 or more nm, 55 or more nm, 60 or more nm, 65 or more nm, 70 or more nm, 75 or more nm, 80 or more nm, 85 or more nm, 90 or more nm, 95 or more nm, 100 or more nm) thick. The buffer layer may be at most about 100 or fewer nm (e.g., 95 or fewer nm, 90 or fewer nm, 85 or fewer nm, 80 or fewer nm, 75 or fewer nm, 70 or fewer nm, 65 or fewer nm, 60 or fewer nm, 55 or fewer nm, 50 or fewer nm, 45 or fewer nm, 40 or fewer nm, 35 or fewer nm, 30 or fewer nm, 25 or fewer nm, 20 or fewer nm, 15 or fewer nm, 10 or fewer nm, 5 or fewer nm) thick. The ultraviolet damage is often generated by high power ions that penetrate deep into the bulk of the ETL 125 and the perovskite layer 120, breaking or damaging molecular bonds and causing degradation in both the open circuit voltage and series resistance. The use of a low-power PVD to create the buffer layer may block (at least partially) high energy ions in subsequent process steps from reaching the ETL 125 and the perovskite layer 125.
A bulk layer of IZTO may be deposited on the buffer layer of IZTO at a higher power level (e.g., the power levels listed previously). In some examples, the power ratio for buffer layer deposition to bulk layer deposition can be 1:2 or more (e.g., 1:3 or more, 1:4 or more, 1:5 or more, 1:6 or more, 1:7 or more, 1:8 or more, 1:9 or more, 1:10 or more).
In some examples, a large deposition tool can be used to deposit IZTO on a large (e.g., 1 m or more×0.5 m or more, such as 2 m×1 m) substrate. In such cases, the target can have a dimension of 1 m or more (e.g., 1.5 m or more, 1.6 m or more, 1.8 m or more, 2 m or more, such as up to 4 m, e.g., 3 m or less, 2 m or less, 1.8 m or less).
In some cases, an ultrathin layer of silver may be deposited at the interface between the ETL 125 and the IZTO layer through an evaporation, sputtering, or atomic layer deposition. The ultrathin layer of silver may be at most about 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 angstroms thick. The ultrathin layer of silver may act as a barrier against ultraviolet light or plasma during PVD of the IZTO layer. In some cases, a post-anneal may be performed on the second TCO layer to partially repair some of the damage caused by the ultraviolet light or plasma during the PVD process. The post-anneal may be performed at 100-140 degrees Celsius for 2 to 4 minutes.
A bulk layer of IZTO may be deposited on the buffer layer of IZTO at a deposition energy of at most 0.90 W/cm2, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, or less W/cm2.
Conventionally, the physical vapor deposition process described above can be performed in a chamber that has a shutter disposed between the sputtering source and the target substrate. The shutter may quickly actuate (i.e., open and close) in order to shield the target substrate from the sputtering source for short periods of time. The abrupt nature of the shutter may result in the sensitive perovskite and transport layers being damaged by ion impacts and exposure to UV radiation. Additionally, the entire target substrate is subjected to the whole sequence of TCO deposition, which may be minutes long to achieve a thickness on the order of 300-900 nm to meet sheet resistance and transmission targets. As such, the physical vapor deposition process may intrinsically cause larger than expected ion and UV damage to the target substrate, which may result in defects and recombination sites in the layers of the target substrate, degrading its electrical performance as an electron-hole pair absorber layer.
To address the shortcomings of conventional physical vapor deposition processes, the TCO layers 110 and 130 may instead be fabricated in an inline manufacturing process. The inline manufacturing process may be performed in multiple process chambers where deposition of selected target materials occurs. A conveyor belt can transport the target substrate between the multiple process chambers. The inline manufacturing process may provide for the deposition of TCO layers while maintaining low resistivity, good transmission, and uniform thickness of the perovskite solar cell. The inline manufacturing process can be a vertical or horizontal process. An example of a horizontal inline manufacturing system is illustrated in
The inline manufacturing process may reduce the defects formed in the ETL 125 and the perovskite layer 120 due the ultraviolet light and argon/oxygen ions generated by the plasma during the TCO physical vapor deposition process. Utilization of a moving conveyor belt in the multiple process chambers may reduce the defects formed in the ETL 125 and the perovskite layer 120. The multiple chamber system may minimize the amount of time the target substrate is exposed to plasma deposition. The target substrate may only be exposed to deposition in certain chambers. For example, the target substrate may not be exposed to deposition in a buffer chamber, whereas the target substrate is exposed to deposition in process chambers where the first and second TCO layers are fabricated. In some embodiments, a target substrate containing the top glass sheet 105, the first TCO layer 110, the HTL 115, the perovskite layer 120, and the ETL 125 is loaded onto the conveyor belt of the inline PVD manufacturing tool. The conveyor transports the target substrate into a target chamber, with the ETL layer 125 facing the TCO source for TCO deposition. Depending on the desired thickness and composition of the second TCO layer and the throughput of the TCO source, there may be one or multiple target substrates inside the chamber at a time or multiple chambers with a single target substrate. Each chamber may be separated by gates to minimize cross-contamination and to minimize damage due to plasma exposure. In some cases, the target substrate passes through a first deposition chamber for deposition of a buffer layer of ITO. Then the substrate passes through a buffer chamber, and finally through a second deposition chamber for deposition of a bulk layer of ITO. The buffer chamber may prevent cross-contamination between the first deposition chamber and the second deposition chamber if, for example, the composition or deposition parameters of the two ITO layers are different.
To further reduce direct exposure to deposition, a moving target substrate on the conveyor belt ensures that each portion of the target substrate is only subject to direct exposure to deposition until that portion of the target substrate moves past the deposition area. The amount of time each portion of the target substrate is exposed to direct deposition depends on the speed of the conveyor belt. The speed of the conveyor belt can be adjusted to minimize the amount of time each portion of the substrate is subjected to direct exposure while still ensuring each layer is sufficiently deposited on the target substrate. The moving conveyor belt provides a more gradual deposition profile on the target substrate, in contrast to the more abrupt profile generated by a conventional shutter.
The multiple chambers may also include shields, or other blocking obstacles, between chambers to ensure ions and UV exposure in other chambers are blocked when the target substrate enters a chamber with no deposition. The multiple chambers may also comprise shields around the deposition area to block ions and UV radiation from areas of the substrate that are not directly exposed to the deposition. Further, the multiple chamber system allows for TCO layer deposition at uniform thickness and at much lower plasma power without compromising deposition duration.
The inline manufacturing process can also implement the techniques mentioned above (e.g., optimizing process parameters like gas flow/pressure, deposition power, thickness and materials, use of a buffer layer, lowering deposition energy, use of an ultrathin layer of silver, and use of an annealing process) when fabricating the second TCO layer to further reduce the defects formed in the ETL 125 and the perovskite layer 120. The process limits the number of defects both at the interface between the second TCO layer 130 and the ETL 125, and in the bulk of the ETL 125 and the perovskite layer 120. Other examples of process parameters may include, but are not limited to, chemical formation parameters (e.g., solvent composition, presence or absence of additives, one-operation formulations, two-operation formulations, etc.), ultrasonic spray on process parameters (e.g., spray volume, spray speed, ultrasonic power, lateral speed of the substrate, nozzle height, nozzle width, nozzle angle, environmental factors, humidity, atmospheric composition, temperature, etc.), post application treatment parameters (e.g., dry duration, rinse duration, exterior environmental parameters, solvent chemistry, anneal time, anneal temperature, etc.), transport layer application parameters (e.g., application type, surface conditions, layer thickness, layer conformality, etc.), or the like, or any combination thereof.
Operation 310 may include applying one or more first transparent conductive materials to the substrate to form a first transparent conductive layer (312). The first transparent conducting layer may comprise a transparent conductive oxide (e.g., indium tin oxide (ITO), indium zinc oxide, aluminum zinc oxide, indium cadmium oxide, etc.), a transparent conductive polymer (e.g., poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), poly(4,4-dioctyl cyclopentadithiophene), etc.), carbon nanotubes, graphene, nanowires (e.g., silver nanowires), metallic grids (e.g., grid contacts comprising metals), thin films (e.g., thin metal films), conductive grain boundaries, or the like, or any combination thereof. The transparent conducting layer may have a full spectrum transparency of at least about 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or more. The transparent conducting layer may have a full spectrum transparency of at most about 99.9%, 99%, 98%, 97%, 96%, 95%, 90%, 85%, 80%, 75%, 70%, 60%, 50%, 40%, 30%, 20%, or less. The transparent conducting layer may have a full spectrum transparency in a range as defined by any two of the proceeding values. For example, the transparent conducting layer can have a full spectrum transparency of 75% to 85%. The transparent conducting layer may have a transparency over a spectral band of at least about 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or more. The transparent conducting layer may have a transparency over a spectral band of at most about 99.9%, 99%, 98%, 97%, 96%, 95%, 90%, 85%, 80%, 75%, 70%, 60%, 50%, 40%, 30%, 20%, or less. For example, the transparent conducting layer can have a transmission of 85% over the wavelength range from 400 nm to 1200 nm. The transparent conducting layer can function as a barrier to the perovskite layer for moisture, gas, dust, and the like. The transparent conducting layer can also prevent the diffusion of ions (e.g., metal ions) which may impact the performance of the perovskite layer. Methods for forming transparent conductive oxide layers are described elsewhere herein. For example, the transparent conducting oxide layers may be formed using the PVD and/or inline manufacturing processes described herein.
Operation 310 may include applying one or more hole transport layers to the transparent conductive layer (313). The one or more hole transport layers may be configured to shuttle holes from an absorbing layer to the transparent conductive layer and out of the solar module. The one or more hole transport layers may comprise organic molecules (e.g., 2,2′,7,7′-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (Spiro-OMeTAD)), inorganic oxides (e.g., nickel oxide (NiOx), copper oxide (CuOx), cobalt oxide (CoOx), chromium oxide (CrOx), vanadium oxide (VOx), tungsten oxide (WOx), molybdenum oxide (Mo Ox), copper aluminum oxide (CuAlO2), copper chromium oxide (CuCrO2), copper gallium oxide (CuGaO2), etc.), inorganic chalcogenides (e.g., copper iodide (CuI), copper indium sulfide (CuInS2), copper zinc tin sulfide (CuZnSnS4), cupper barium tin sulfide (CuBaSnS4), etc.) other inorganic materials (e.g., copper thiocyanate (CuSCN), etc.), organic polymers, or the like, or any combination thereof. For example, a glass substrate covered in indium tin oxide can be coated with nickel oxide to form a hole transport layer on the transparent conducting layer.
In some examples, operation 310 includes performing one or more lithography operations on the hole transport layer (314). The one or more lithography operations may comprise optical lithography (e.g., (extreme) ultraviolet lithography, x-ray lithography, laser scribing, etc.), electron beam lithography, ion beam lithography, nanoimprint lithography, other direct writing processes (e.g., dip-pen lithography, inkjet printing), or the like, or any combination thereof. For example, a plurality of features can be inscribed onto the hole transport layer using a laser scribe. The one or more lithography operations may comprise the addition and/or subtraction of features. For example, features can be cured and made permanent. In another example, features can be formed by the removal of material from the target.
Returning to
The ultrasonic spray-on application may comprise the use of a plurality of spray nozzles. The ultrasonic spray-on process may comprise the use of a single spray nozzle. For example, the single spray nozzle can be configured to raster across the application area to provide coverage of the area. A plurality of different types of spray nozzles may be tested for formation of a predetermined uniformity and/or thickness of the film deposited by the spray nozzle, and an optimal spray nozzle may be selected from the plurality of different types of spray nozzles. Once an optimal spray nozzle is selected, a plurality of that type of nozzle may be used in the ultrasonic spray-on application. The plurality of nozzles may form a bank of nozzles configured to spray over a large area to improve throughput and efficiency. The bank of nozzles may be a strip of nozzles (e.g., a line of nozzles across a single dimension), a two-dimensional arrangement of nozzles (e.g., nozzles distributed over a rectangular shape), a three-dimensional arrangement of nozzles (e.g., a plurality of nozzles distributed in three dimensions). The spray nozzles may be adjusted to dispense at an angle. The angle may be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or more degrees off of a parallel line from the substrate. The angle may be at most about 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, or less degrees off of a parallel line from the substrate. The angle may be configured to reduce or eliminate the precursor missing the substrate and fouling other components of the manufacturing process. Use of an ultrasonic spray-on application can enable a roll to roll inline fabrication process. In the roll to roll inline fabrication process, a series of nozzle banks can each sequentially add different layers to a substrate, the substrate can be processed (e.g., annealed, laser scribed, etc.), and a finished photovoltaic cell can be generated on a single line. Using a roll to roll process can result in significant improvements in cost and speed of production as compared to step by step manufacture processes.
The one or more perovskite precursors can include one or more lead halides (e.g., lead fluoride, lead chloride, lead bromide, lead iodide, etc.), lead salts (e.g., lead acetates, lead oxides, etc.), other metal salts (e.g., manganese halides, tin halides, metal oxides, metal halides, etc.), organohalides (e.g., formamidinium chloride, formamidinium bromide, formamidinium iodide, methylammonium chloride, methylammonium bromide, methylammonium iodide, butylammonium halides, etc.), alkali metal salts (e.g., alkali metal halides, etc.), alkali earth metal salts (e.g., alkali earth metal halides, etc.), perovskite nanoparticles, or the like, or any combination thereof. A plurality of perovskite precursors can be used as the one or more perovskite precursors. For example, both methylammonium iodide and butylammonium iodide can be used as perovskite precursors. In this example, the methylammonium iodide can be at about a 1:99, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 10:90, or 99:1 ratio with the butylammonium iodide. In another example, mixtures of lead halides can be used as a portion of the perovskite precursors. Using different mixtures of lead halides may permit tuning of the bandgap of the perovskite layer. For example, using different mixtures of lead (II) bromide and lead (II) iodide can result in different bandgaps. Using different amounts of lead (II) chloride can affect the crystal stability of the perovskite layer and can prevent phase segregation within the layer. The amount of lead (II) chloride added may be greater than the amount of lead (II) bromide added by weight. The amount of lead (II) chloride added may be less than the amount of lead (II) bromide added by weight. The amount of lead (II) chloride added may be the same as the amount of lead (II) bromide added by weight. The amount of lead (II) iodide soluble in a solution may be related to the amount of lead (II) bromide and lead (II) chloride in the solution. For example, adding in more lead (II) bromide and lead (II) chloride to a solution of lead (II) iodide can improve solubility of the lead (II) iodide and result in decreased particulate in the perovskite layer.
The one or more perovskite precursors may be one or more perovskite precursor solutions. For example, a lead (II) iodide solution in a solution of dimethyl sulfoxide can be a perovskite precursor. A perovskite precursor may be in a solution of at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or more weight percent perovskite precursor. A perovskite precursor may be in a solution of at most about 99, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1, or less weight percent perovskite precursor. The solution may comprise one or more solvents. Examples of solvents include, but are not limited to, polar solvents (e.g., water, dimethyl sulfoxide, dimethylformamide, ethers, esters, acetates, acetone, etc.), non-polar solvents (e.g., hexanes, toluene, etc.), or the like, or any combination thereof. Proper mixing of the solvent as well as solvent composition can contribute to controlled solvent removal speeds and thus impact grain development as well as bulk defect formation. Tuning the interaction of the coordination strength of a solvent and the evaporation rate of a precursor solution can enable better control of the perovskite film that is formed as well as the reaction kinetics of the formation. For example, a weakly coordinating solvent that quickly evaporations may form a more disordered film, but may also result in less residual solvent being present in the film. Mixtures of solvents can improve solute solubility, decrease evaporation rates, improve performance of application methods, and the like. For example, a combination of NMP and DMSO can increase solute solubility and decrease solvent evaporation rates. In this example, the properties of the NMO/DMSO mixture can decrease premature crystallization of perovskite and improve film quality. In another example, adding NMP to DMF can increase spray width of the solution through an ultrasonic spray on apparatus, which can provide greater flexibility in the spray on parameters used.
The one or more perovskite precursors can include one or more additives. The addition of the one or more additives may be configured to reduce and/or eliminate defects within perovskite layers as prepared elsewhere herein. The one or more additives may comprise one or more recrystallization solvents. The one or more recrystallization solvents may be added to a solution comprising the one or more perovskite precursors. The one or more recrystallization solvents may be applied after deposition of the one or more perovskite precursors and/or after an annealing of the one or more perovskite precursors. For example, a lead halide precursor can be applied and subsequently a recrystallization solvent can be applied, and the perovskite precursors can be further annealed to orient the lead halide precursor for better methylammonium iodide integration. Examples of recrystallization solvents include, but are not limited to, halobenzenes (e.g., chlorobenzene, bromobenzene, etc.), haloforms (e.g., chloroform, iodoform, etc.), ethers (e.g., diethyl ether), or the like, or any combination thereof.
A variety of parameters may be tuned to provide a predetermined perovskite layer. Examples of parameters include, but are not limited to, perovskite precursor solution application temperature, volume application rate, ultrasonic power of an ultrasonic spray-on instrument, lateral speed of precursor application (e.g., the speed of a substrate moving through an applicator), applicator height (e.g., the distance from an applicator to the substrate, environmental factors (e.g., humidity, reactive gas content, temperature, etc.), wetting surface energy, or the like, or any combination thereof. Any portion of process 300, including the application of the perovskite precursors, may take place in a controlled environment. The controlled environment may have a relative humidity of at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, or more. The controlled environment may have a relative humidity of at most about 99%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less. The controlled environment may comprise a controlled atmosphere. The controlled atmosphere may comprise inert gasses (e.g., nitrogen, noble gases, etc.). The controlled atmosphere may have an oxygen content of at least about 1 part per million (ppm), 10 ppm, 50 ppm, 100 ppm, 500 ppm, 1,000 ppm, 5,000, ppm, 1%, 5%, 10%, 15%, 20%, or more. The controlled atmosphere may have an oxygen content of at most about 20%, 15%, 10%, 5%, 1%, 5,000 ppm, 1,000 pm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, 1 ppm, or less. The controlled atmosphere may be at a temperature of at least about 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, or more degrees Celsius. The controlled atmosphere may be at a temperature of at most about 200, 190, 180, 170, 160, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or less degrees Celsius.
The process 300 can include performing one or more processing operations to the perovskite precursors to generate a perovskite layer (340). If the perovskite precursors are instead deposited as a completed perovskite layer, operation 340 may be omitted.
Operation 340 may comprise performing one or more processing operations on the perovskite precursors to generate a perovskite layer (342). The one or more processing operations may comprise annealing, light exposure (e.g., ultraviolet light exposure), agitation (e.g., vibration), functionalization (e.g., surface functionalization), electroplating, template inversion, or the like, or any combination thereof. For example, a substrate with perovskite precursors can be annealed to form a perovskite layer from the precursors. In another example, perovskite precursors can be annealed and subsequently functionalized. The annealing may be annealing under inert atmosphere (e.g., argon atmosphere, nitrogen atmosphere). The annealing may be under a reactive atmosphere (e.g., an atmosphere comprising a reagent (e.g., methylammonium)). The annealing may be at a temperature of at least about 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, or more degrees Celsius. The annealing may be at a temperature of at most about 200, 190, 180, 170, 160, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or less degrees Celsius. The annealing may be at a temperature range as defined by any two of the proceeding values. For example, the annealing can be at a temperature of 90 to 120 degrees Celsius. The annealing may be for a time of at least about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 75, 90, 105, 120, or more minutes. The annealing may be for a time of at most about 120, 105, 75, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or less minutes. The annealing may be for a time range as defined by any two of the proceeding values. For example, the annealing can be for a time of about 5 to about 15 minutes. There may be a plurality of annealing processes applied to the substrate. For example, a substrate can be annealed at a first time and temperature, and subsequently annealed again at a second time and temperature. Such additional annealing processes can reduce the number of defects present in the perovskite layer and improve performance.
Operation 340 can include applying one or more additional layers to the perovskite layer (343). The one or more additional layers may comprise one or more additional perovskite layers. For example, a second perovskite layer with a different bandgap can be applied to the first perovskite layer. The one or more additional layers may comprise one or more additional perovskite precursors. For example, iodine gas can be applied to form an iodine layer on a perovskite and/or perovskite precursor layer. The one or more additional layers may comprise one or more washing operations. A washing operation may comprise an application of a solvent to the perovskite layer. Examples of solvents include, but are not limited to, water, non-polar organic solvents (e.g., hexanes, toluene, etc.), polar organic solvents (e.g., methanol, ethanol, isopropanol, acetone, etc.), ionic solvents, or the like. The one or more additional layers may comprise one or more passivating layers. A passivating layer may comprise a reagent configured to passivate and/or stabilize the perovskite layer. For example, an application of a solution comprising phenethylammonium iodide can passivate and stabilize the grains of the perovskite layer.
Operation 340 can include performing one or more lithography operations on the one or more additional layers and/or the perovskite layer (344). The one or more lithography operations may be one or more lithography operations as described elsewhere herein. For example, a laser scribe can be used to generate features on a perovskite layer.
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Operation 350 can include applying an electron transport layer to the perovskite layer (352). The electron transport layer may be applied by methods and systems as described elsewhere herein (e.g., physical vapor deposition, ultrasonic spray-on, etc.). The electron transport layer may comprise a material with a conduction band minimum less than that of the perovskite layer. For example, if the perovskite layer has a conduction band minimum of −3.9 eV, the electron transport layer may have a conduction band minimum of −4 eV. Examples of electron transport layer materials include, but are not limited to titanium oxide (e.g., TiO2), zinc oxide, tin oxide, tungsten oxide, indium oxide, niobium oxide, iron oxide, cerium oxide, strontium titanium oxide, zinc tin oxide, barium tin oxide, cadmium selenide, indium sulfide, lead iodide, organic molecules (e.g., phenyl-C61-butyric acid methyl ester (PCBM), poly(3-hexylthiophene-2,5-diyl) (P3HT), etc.), lithium fluoride, buckminsterfullerene (C60), or the like, or any combination thereof. Operation 350 may optionally comprise performing one or more lithography operations on the electron transport layer (353). The one or more lithography operations may be one or more lithography operations as described elsewhere herein. For example, a laser scribe can be used to generate features on the electron transport layer.
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Operation 360 can include applying a second transparent conducting layer to the electron transport layer (362). The second transparent conducting layer may be of the same type as the first transparent conducting layer. For example, both the first and second transparent conducting layers may be indium tin oxide. The second transparent conducting layer may be of a different type as the first transparent conducting layer. The second transparent conducting layer may be deposited as described elsewhere herein (e.g., physical vapor deposition, etc.).
Operation 360 can include applying one or more busbars to the second transparent conducting layer (363). The one or more busbars may be applied as busbars (e.g., preformed busbars are applied to the second transparent conducting layer). For example, a mask can be used to form the busbars from an evaporation process. The one or more busbars may be applied as a solid film and subsequently formed into the busbars. For example, a silver film can be deposited onto the second transparent conductive layer and etched to form the busbars. In another example, a laser scribe can be used to form the busbars from a silver film. Operation 360 may optionally comprise performing one or more lithography operations on the electron transport layer (364). The one or more lithography operations may be one or more lithography operations as described elsewhere herein. For example, a laser scribe can be used to generate features on the second transparent conducting layer. The busbars may be attached to at least about 2, 3, 4, or more terminals. The busbars may be attached to at most about 4, 3, 2, or less terminals. The terminals may be configured to form a parallel connection with one or more additional photovoltaic modules. The terminals may be configured to form a series connection with one or more additional photovoltaic modules. The terminals may be scribed (e.g., laser scribed). The terminals may be configured to enable connection of a perovskite photovoltaic device with another photovoltaic device prior to a lamination of the two photovoltaic devices. For example, a perovskite photovoltaic device can be connection via two terminals to a silicon photovoltaic device.
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The encapsulant may be applied across the second transparent conducting layer (e.g., applied to the whole layer), to a portion of the second transparent conducting layer (e.g., a portion of the layer), to the edges of the second transparent conducting layer (e.g., as a seal over the entire stack of layers), or the like, or any combination thereof. For example, the encapsulant can be applied on the edge of the full stack of layers to prevent moisture and oxygen diffusion into the stack. The encapsulant may be applied to the first conductive layer as well as the second conductive layer. For example, the substrate can comprise an encapsulant between the substrate and the first conducting layer. Example 3 below describes the use of PDMS as an encapsulant. Other examples of encapsulants include, but are not limited to, HelioSeal™, silicon glue, butyl-based sealants, or the like. For edge encapsulation, the encapsulant may comprise tape. The tape may be an adhesive backed barrier. The encapsulant may be placed such that the encapsulant ends at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or more millimeters from the edge. The encapsulant may be place such that the encapsulant ends at most about 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, or fewer millimeters from the edge.
Subsequently to operation 370, the completed stack (e.g., the substrate, perovskite layer, and other layers) may be used as a front panel for an additional photovoltaic module. For example, the completed stack can be configured to be a front junction of a two-junction photovoltaic module. The completed stack may be configured for use as a substrate for an additional stack. For example, the stack can be used as the initial substrate for growth of a silicon photovoltaic module. The stack may be laminated to a second photovoltaic cell. The stack may be laminated at a temperature of at least about 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, or more degrees Celsius. The stack may be laminated at a temperature of at most about 200, 190, 180, 170, 160, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or less degrees Celsius.
The process 1300 may comprise applying a lead layer to the hole transport layer (1320). The lead layer may comprise lead metal (e.g., lead (0)), lead salts (e.g., lead (II) acetate, lead (II) halide, lead (I) salts, etc.), or any combination thereof. For example, a metallic lead layer may be deposited onto the hole transport layer, and a layer of lead (II) acetate may be applied to the lead layer. The lead layer may be deposited as described elsewhere herein. For example, the lead may be deposited by physical vapor deposition. The lead layer may be deposited by the same deposition method and/or deposition machinery as the hole transport layer. For example, the same physical vapor deposition instrument can be used to deposit both the hole transport layer as well as the lead layer.
The process 1300 may comprise applying an organic halide salt layer to the lead layer (1330). The organic halide may be an organic halide as described elsewhere herein. For example, a mixture of methylammonium iodide, methylammonium chloride, and formamidinium iodide can be applied to the lead layer. The organic halide layer may be applied by a deposition process as described elsewhere herein. For example, the organic halide can be applied by a spin coating process, an ultrasonic spray-on process, or the like.
The process 1300 may comprise applying a halide layer to the organic halide layer (1340). The halide layer may comprise halides (e.g., fluorine, chlorine, bromine, iodine, etc.), oxyhalides (e.g., chlorate, etc.), other halide containing compounds, or the like, or any combination thereof. For example, the halide layer may comprise iodine. In another example, the halide layer may be iodine. The halide layer may be applied to the organic halide salt layer by deposition processes as described elsewhere herein. The halide can be applied as a gas. For example, iodine can be sublimated and applied as a gas to the organic halide salt layer. The halide can be applied evenly across the surface of the organic halide salt layer. To apply the halide uniformly, a variety of different application devices can be used. An example of an application device may be a ‘shower head’ (e.g., an application head comprising a plurality of holes. An example of a shower head for application of a perovskite precursor may be found in
The process 1300 may comprise performing one or more processing operations to form a perovskite layer (1350). The perovskite layer may be a perovskite layer as described elsewhere herein (e.g., a perovskite layer from
In certain examples, the perovskite layer is formed by spraying on a solution including precursors for the perovskite layer. A quench solution may be applied to the precursors to form the perovskite layer. The solution may comprise all of the precursors for the perovskite layer. For example, the solution can comprise a lead halide, an organohalide, and a halide. The solution may comprise perovskite precursors as described elsewhere herein. The solution may be applied by processes as described elsewhere herein. For example, the solution can be applied by ultrasonic spray on techniques. The solution may be treated after application. For example, the solution can be heated to remove solvent from the solution. The solution may not be treated after application. The quench solution may be applied to a solution (e.g., a precursor solution). The quench solution may be applied to dried precursors. The quench solution may comprise an antisolvent (e.g., a solvent that the perovskite precursors are less soluble in than the solvent for the precursor solution). Examples of antisolvents include, but are not limited to polar solvents (e.g., alcohols, acetone, etc.), long-chain non-polar solvents (e.g., octadecene, squalene, etc.), or the like, or any combination thereof. The quench solution may be applied as described elsewhere herein. For example, the quench solution may be applied by ultrasonic spray-on techniques. The solution may be subjected to one or more atmospheric conditions to aid in the removal of the solvent. The one or more atmospheric conditions may comprise reduced pressure (e.g., application of a vacuum), increased pressure (e.g., blowing gas over the substrate), or the like, or a combination thereof. The reduced pressure may comprise application of a partial vacuum around the substrate. Such a vacuum may pull solvent form the film to effect rapid solvent removal and produce a high quality film. The increased pressure may comprise use of an air knife or similar blowing scheme to aid in the removal of the solvent. Such high quality films may appear specular under visual inspection. After application of the precursor solution, the solution may be given time to self-level prior to solidification. For example, the precursor solution can be allowed to sit on the substrate for sufficient time to level prior to removal of the solvent and preparation of the perovskite layer.
The method may further comprise fabricating perovskite-on-glass as described elsewhere herein (2020). The perovskite-on-glass may have at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more layers. The perovskite-on-glass may have at most about 10, 9, 8, 7, 6, 5, 4, 3, 2, or less layers.
The method may further comprise laser scribing the perovskite-on-glass to form perovskite cells or strips (2030). The fabricating may comprise use of fabrication techniques as described elsewhere herein. For example, the fabricating can comprise use of a laser scribe to define the one or more perovskite solar cells. The one or more perovskite solar cells may be a plurality of perovskite solar cells. The one or more perovskite solar cells may be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or more perovskite solar cells. The one or more perovskite solar cells may be at most about 99, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or less perovskite solar cells. The plurality of perovskite solar cells may be connected in series. The plurality of perovskite solar cells may be connected in parallel. The laser scribing may separate the perovskite layer into a plurality of segments. The plurality of segments may be formed into a plurality of perovskite solar cells. For example, contacts can be applied to the plurality of segments to extract charge from the plurality of segments.
The laser scribing may be configured to generate a plurality of perovskite cells which, when connected together, have a same or substantially same voltage output as the silicon module. The voltage output of the perovskite layer per unit area can be known, and the perovskite layer can be scribed to form perovskite cells of a size to provide a predetermined voltage. For example, a perovskite layer can be scribed to form 5 perovskite sub-modules each comprising 40 perovskite solar cells to match a silicon solar module that has a same voltage output as the 40 perovskite solar cells. In this example, the 5 perovskite sub-modules can be connected in parallel to increase the current produced by the perovskite layer while maintaining the voltage match with the silicon module.
The method may further comprise connecting the cells of the silicon solar panel to the perovskite solar cells to form a tandem module (2040). The silicon solar panel and the perovskite solar cells may be in a voltage matched configuration. The voltage matched configuration may be as described elsewhere herein. For example, the silicon solar cells can have the same voltage as the perovskite solar cells. The perovskite solar cells may be connected to one another in parallel. The perovskite solar cells may be connected to one another in series. The perovskite solar cells may be connected such that there are a plurality of modules in the perovskite layer. For example, rows of the perovskite solar cells can be each connected in series and the connected rows can be connected in parallel. The silicon solar panel and the perovskite solar panel may be connected as described elsewhere herein. For example, the perovskite solar cells can be connected via copper (or another metal, charge collection tape, etc.) terminals to the same junction box as the silicon solar cells.
The method may further comprise encapsulating the module (2050). The encapsulating may comprise applying an encapsulant as described elsewhere herein. For example, the encapsulating can comprise applying a thermal-plastic polyolefin to the perovskite layer. In another example, the encapsulating can comprise use of a transparent conducting oxide.
The method may comprise applying a plurality of contacts to the one or more perovskite solar cells to electrically couple the one or more perovskite solar cells. The plurality of contacts may be applied using one or more processes as described elsewhere herein. For example, the plurality of contacts can be evaporated onto the perovskite solar cells. In another example, the plurality of contacts can be lithographically applied to the perovskite solar cells. The method may comprise applying an encapsulant to the one or more perovskite solar cells. The applying may be as described elsewhere herein. For example, the encapsulant can be applied via evaporation. In another example, the encapsulant can be spread as a viscous solution onto the perovskite solar cell. The encapsulant may be as described elsewhere herein. For example, the encapsulant may be a thermal-plastic polyolefin. The method may comprise applying an edge seal to the one or more perovskite solar cells. The edge seal may be as described elsewhere herein. For example, the edge seal can be HelioSeal™.
The silicon solar panel and the perovskite solar panel may be electronically coupled to a same junction box. Such coupling to the same junction box may allow for simple integration of the perovskite layer into existing silicon solar modules. Such coupling may also provide for simple installation of the tandem solar module, as there may be a single output from the tandem module instead of multiple outputs.
The segments can include at least about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 125, 150, 175, 200, 250, 300, 400, 500, or more segments. The segments can include at most about 500, 400, 300, 250, 200, 175, 150, 125, 100, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or fewer segments. The number of segments can be in a range defined by any two of the proceeding values. For example, the number of segments can be from about 10 to about 200 segments.
The perovskite top module may comprise one or more channels 1607, as well as one or more terminals 1608. The channels may be generated by methods described elsewhere herein. For example, the channels can be cut in with a laser scribe. The channels may be configured to isolate different perovskite solar cells from one another. In this way, a plurality of perovskite solar cells can be formed in the perovskite top module. Additional channels perpendicular to the channels can be used to form a grid of solar cells. For example, a 5 by 40 array of perovskite solar panels can be formed out of the perovskite layer. The perovskite top module may comprise at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or more perovskite solar cells. The perovskite top module may comprise at most about 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or fewer perovskite solar cells. For example, the perovskite top layer can comprise 40 solar cells separated by channels. The perovskite solar cells can be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, or more millimeters wide. The perovskite solar cells can be at most about 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or less millimeters wide. The perovskite solar cells can be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 150, 200, 250, 500, 750, 1,000, or more millimeters long. The perovskite solar cells can be at most about 1,000, 750, 500, 250, 200, 150, 100, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or fewer millimeters long. The perovskite solar cells can be strips (e.g., solar cells that stretch up to the length of the module). The strips may be connected in series or parallel. In some cases, the perovskite solar cells may be connected to one another in series. The perovskite solar cells may be connected to one another in parallel. Similarly,
The arbitrary size of the perovskite solar cells may enable the arbitrary selection of the voltage output of the perovskite top module. For example, the perovskite solar cells can be formed such that the cells produce a predetermined voltage upon illumination. The perovskite solar cells can be configured to generate a total voltage that is substantially matched to the silicon solar module. For example, for a silicon solar cell with a 42 volt output, the perovskite solar cells can be configured to generate 44 volts. The perovskite top module may generate a voltage within at least about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, or more of the voltage of the silicon solar module. The perovskite top module may generate a voltage within at most about 99%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or less of the voltage of the silicon solar module. The matching or substation matching of the perovskite top module's voltage with the voltage of the silicon solar module can result in a voltage matched condition between the two modules. The voltage matched condition can produce a hybrid module with a higher current output than a hybrid module that is not voltage matched. The silicon solar panel and the perovskite solar panel may have a substantially similar area. For example, the perovskite layer can cover the entire silicon solar panel. In this example, the total power of the module can be maximized, as all of the area of available solar light is utilized. The perovskite solar panel may be at least about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, or more of the area of the silicon solar panel. The perovskite solar panel may be at most about 99%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or less of the area of the silicon solar panel.
The perovskite layer described herein may have a composition of MAn1FAn2CSn3PbX3, wherein MA is methylammonium and FA is formamidinium. n1, n2, and n3 may independently be greater than 0 and/or less than 1. n1+n2+n3 may equal 1. A perovskite solar cell comprising said perovskite layer may retain at least about 80% solar conversion efficiency after 300 hours of illumination under one sun conditions in an air atmosphere at 45° C. The perovskite layer may be used as described elsewhere herein (e.g., used as an absorbing layer for a perovskite photovoltaic).
In the above equation, X may be selected from the group consisting of fluorine, chlorine, bromine, and iodine. For example, X can be iodine. X may be a combination of two or more of fluorine, chlorine, bromine, and iodine. For example, X may be a mixture of chlorine and iodine. The combination may comprise individual components having a concentration of at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, or more percent. The combination may comprise individual components having a concentration of at most about 99, 98, 97, 96, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1 or less percent. For example, the combination may be a mixture of about 1% chlorine and 99% iodine. The combination may comprise individual components having a concentration in a range as defined by any two of the previous values. For example, the combination can be a mixture of about 1%-5% bromine and about 95%-99% iodine.
In the proceeding formula, n1, n2, and n3 may individually be greater than at least about 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.96, 0.97, 0.98, 0.99, or more. In the proceeding formula, n1, n2, and n3 may individually be less than at most about 0.99, 0.98, 0.97, 0.96, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.14, 0.13, 0.12, 0.11, 0.1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.05, 0.01, 0.005, 0.001, 0.0005, 0.0001, or less. In the proceeding formula, n1, n2, and n3 may individually have a range as defined by any two of the proceeding values. For example, n1 can be about 0.001 to about 0.05, n2 can be about 0.8 to about 0.989, and n3 can be about 0.01 to about 0.15.
The cations of the formula may be as described above (e.g., methylammonium, formamidinium, cesium, butylammonium). Examples of other cations that may be used include, but are not limited to, imidazolium, dimethylammonium, guanidinium, ammonium, methylformamidinium, tetramethylammonium, trimethylammonium, rubidium, copper, palladium, platinum, silver, gold, rhodium, ruthenium, sodium, potassium, iron, other inorganic cations, other organic cations, or the like, or any combination thereof. The perovskite layer may not comprise additional additives. For example, the perovskite layer may not comprise thiocyanate. In another example, the perovskite layer may not comprise carbamides. The perovskite layer may be configured to provide high performance and longevity without additional additives. The lack of additional additives may provide lower cost and easier manufacturing of the perovskite layer. The inclusion of the cesium cation (or an equivalent alternate cation) may improve the thermal stability of the perovskite layer. For example, the presence of cesium can increase the strength of the molecular bonds of the lead halide structure of the perovskite layer. The cesium ions may also have a lower vapor pressure than organic ions, which may contribute to the thermal stability of the perovskite layer. The inclusion of formamidinium may be more resilient to high temperatures due to their increased molecular weight as compared to other organic cations (e.g., methylammonium). Due to a possible intrinsic instability of a pure formamidinium perovskite, including cesium and/or methylammonium cations can improve the crystalline stability while maintaining thermal stability. Adding too many light organic cations (e.g., methylammonium) can reduce thermal stability. Adding a small percentage of butylammonium iodide can improve the quality of the perovskite layer due to the larger molecular structure of butylammonium being better able to fill the gaps in the perovskite crystalline structure to better passivate defects or imperfects within the crystal, which can in turn achieve higher quality or performance perovskite layers.
The perovskite solar cell may be a perovskite solar cell as described elsewhere herein. For example, the perovskite solar cell may be a solar cell formed on a top glass of a silicon solar cell. The perovskite layer may retain at least about 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or more percent of the initial conversion efficiency value after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. The perovskite layer may retain at most about 99, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, or less percent of the initial conversion efficiency value after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. The perovskite layer may retain a percent of the initial conversion efficiency value after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. as defined by any two of the proceeding values.
In another aspect, the present disclosure provides a method. The method includes providing a substrate. A perovskite precursor may be applied to the substrate. The perovskite precursor may be annealed to form a perovskite layer. The perovskite layer may comprise a composition of MAn1FAn2CSn3PbX3. MA may be methylammonium. FA may be formamidinium. n1, n2, and n3 may independently be greater than 0 and/or less than 1. n1+n2+n3 may equal 1. A perovskite solar cell comprising said perovskite layer may retain at least about 80% solar conversion efficiency after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. The perovskite layer may be subjected to an encapsulation lamination process at a temperature of at least about 120° C. The method may be as described elsewhere herein. For example, the method can be process 300 of
The temperature of the encapsulation lamination process may be at least about 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, or more degrees Celsius. The temperature of the encapsulation lamination process may be at a temperature of at most about 200, 190, 180, 170, 160, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or less degrees Celsius. The temperature of the encapsulation lamination process may be in a temperature range as defined by any two of the proceeding values. The encapsulation may be as described elsewhere herein (e.g., with respect to encapsulant 135 of
The perovskite solar cell may be a perovskite solar cell as described elsewhere herein. For example, the perovskite solar cell can be a solar cell formed on a top glass of a silicon solar cell. The perovskite layer may retain at least about 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or more percent of the initial conversion efficiency value after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. The perovskite layer may retain at most about 99, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, or less percent of the initial conversion efficiency value after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. The perovskite layer may retain a percent of the initial conversion efficiency value after 300 hours of illumination under one sun conditions in an air atmosphere at >25° C. and <100° C. as defined by any two of the proceeding values. The perovskite layer may retain at least about 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, or more percent of the initial conversion efficiency value after the encapsulation lamination process. The perovskite layer may retain at most about 99, 98, 97, 96, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 14, 13, 12, 11, 10, or less percent of the initial conversion efficiency value after the encapsulation lamination process. The perovskite layer may retain an efficiency of the initial conversion efficiency value after the encapsulation lamination process as defined by any two of the proceeding values.
The perovskite precursor may be applied as described elsewhere herein. For example, the perovskite precursor can be applied using an ultrasonic spray-on process. In this example, the precursors can be applied in different spray-on operations (e.g., lead (II) iodide can be applied to a substrate, and methylammonium iodide can be applied to the lead iodide). In another example, the perovskite precursors can be applied in a single operation. In this example, a solution comprising all of the precursors for the perovskite layer can be applied and annealed to form the perovskite layer. The annealing process may comprise heating the perovskite layer to at least about 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, or more degrees Celsius. The annealing process may comprise heating the perovskite layer to at most about 200, 190, 180, 170, 160, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or less degrees Celsius. The annealing process may comprise heating the perovskite layer to a temperature range as defined by any two of the proceeding values.
The perovskite layer described herein can include a composition of MAn1FAn2CSn3PbX3, wherein MA is methylammonium and FA is formamidinium. n1 may be of a value from about 0.01 to 0.03. n2 may be of a value from about 0.82 to 0.94. n3 may be of a value from about 0.05 to 0.015. n1+n2+n3 may equal one.
In some examples, the techniques and devices described herein can be used for transparent solar technology devices, such as solar cells designed to absorbing primarily non-visible wavelengths while transmitting much (e.g., substantially all) of the visible light spectrum. Transparent solar technology can be useful in applications including, for example, commercial glass, residential windows, and automotive glass. Use of IZTO for one or both of the transparent electrodes, as described previously, can be useful in transparent solar technology devices compared to electrodes formed from ITO, for instance, due to the higher light visible light transmission of IZTO for at least portions of the visible light spectrum.
The following examples are illustrative of certain systems and methods described herein and are not intended to be limiting.
An incoming glass substrate is coated with indium tin oxide or IZTO followed by nickel (II) oxide in a pair of physical vapor deposition processes to generate a substrate comprising a transparent conductive layer and a hole transport layer. The nickel oxide is then be laser scribed to generate templates of individual photovoltaic cells.
Subsequently, lead (II) iodide in a solution of dimethylformamide and dimethyl sulfoxide is applied to the hole transport layer via an ultrasonic spray process. To the lead (II) iodide, methylammonium iodide in a solution of dimethylformamide and dimethyl sulfoxide is applied via an ultrasonic spray process. The lead (II) iodide and the methylammonium iodide is annealed to permit reaction of the two perovskite precursors and evaporation of the solvents, thus forming a methylammonium lead iodide perovskite layer. To the newly formed perovskite layer, a phenyl-C61-butyric acid methyl ester (PCBM) hole transport layer is applied in a solution of dimethylformamide and dimethyl sulfoxide by an ultrasonic spray process. The hole transport layer is then laser scribed along the same pattern as the nickel oxide.
Subsequently, a second transparent conducting layer of IZTO is applied via physical vapor deposition, followed by application of silver electrodes by a similar physical vapor deposition process or in another embodiment, an attachment of charge collection tape directly to the IZTO layer can be done. The electrodes are cut via laser scribe to form the electrode assembly, and the individual photovoltaic cells are isolated from one another by laser scribe.
Subsequently, the as formed photovoltaic cells is investigated via various metrology techniques such as, for example, scanning electron microscopy (SEM), optical absorption/transmission, x-ray diffraction, atomic force microscopy, ellipsometry, electroluminescence spectroscopy, photoluminescence spectroscopy, time resolved optical spectroscopy, or the like, or any combination thereof.
After application of the second transparent conducting layer, an encapsulant is applied to the back of the photovoltaic cell. The encapsulant is applied prior to the isolation of the photovoltaic cells by laser scribe. A first encapsulant, such as a thermoplastic polyolefin, is applied across the back of the photovoltaic cell while a second encapsulant, such as butyl rubber, is applied to the edges of the photovoltaic cell. The back encapsulant can be optically transparent, while the side encapsulant can be optically transparent or opaque. For example, in certain cases, a higher quality (e.g., lower moisture and gas permeability) encapsulant is placed on the sides of the photovoltaic cell even though it is not optically transparent because the side of the cell does not absorb light, while the encapsulant for the back of the cell is transparent to allow light to pass through to a bottom junction.
Each operation of the production of the perovskite photovoltaic cell is integrated into a single instrument and/or location. For example, a substrate is placed in a single instrument that performs all of the operations of process 300. The perovskite photovoltaic cell is integrated with a second photovoltaic cell (e.g., a silicon photovoltaic cell) in the same instrument the perovskite cell was generated in.
A large area (e.g., 1 meter×2 meter) glass substrate is loaded onto a conveyor belt system configured to guide the glass substrate into an enclosure. The enclosure includes a controlled atmosphere (e.g., low moisture, oxygen content, temperature control, etc.). The enclosure includes multiple ultrasonic spray-on nozzles configured to spray a lead halide solution onto the glass substrate. Subsequent to the application of the lead halide solution, a different set of nozzles in the enclosure applies a methylammonium halide with butylammonium halide solution to the lead halide. The conveyor belt moves the substrate from the lead halide application nozzles to the methylammonium halide/butyl halide solution application nozzles in a set time to permit formation of lead halide crystals that the methylammonium halide/butyl halide integrates into to form a perovskite layer.
After application of the methylammonium halide with butylammonium halide solution, the substrate moves into an annealing oven.
In another example, the formulation consisting of lead halide, methylammonium, formamidinium in a solution of dimethyl sulfoxide and methyl-2-pyrrolidinone (NMP) is applied as a single formulation via a 1-step ultrasonic spray process, following by an accelerating drying process step via applying a low vapor pressure chemical like diethyl ether chemical, before annealing. Within the annealing oven, the substrate is heated to form a perovskite layer with predetermined characteristics (e.g., grain size, thickness, elemental distribution, etc.). The annealing oven may be inline with the conveyor belt (e.g., the conveyor belt moves through the oven to perform the annealing). The annealing oven may be a batch annealing oven (e.g., multiple substrates can be loaded into the oven to be annealed at the same time). The type of annealing oven may be determined by the cycle time of the oven as compared to the anneal duration.
After formation of the perovskite layer, the substrate passes through another set of ultrasonic spray-on nozzles for application of the electron transport layer to the perovskite layer. A second transparent conductive layer is applied via physical vapor deposition to the electron transport layer, electrodes are applied via physical vapor deposition, and the individual photovoltaic cells are isolated via laser scribe. The entire inline process take places on a single conveyor belt.
PDMS was used as an encapsulant in a tandem, 4-terminal, silicon-perovskite solar module (i.e., the solar module 100 of
Table 1 below shows the improvements in voltage and current characteristics when the PDMS encapsulant was used. In particular, short circuit current density improved from 13.93 milliamps per square centimeter (“mA/cm2”) with an airgap between the perovskite solar cell and the silicon solar cell to 22.72 mA/cm2 when the air gap was filled with a spun-on PDMS. Within Table 1, “EFF” refers to efficiency, “FF” refers to fill factor of the current/voltage graph, the “aperture” refers to a test of the photovoltaic cell in which a portion of the cell is illuminated through an aperture that blocks the rest of the cell, while “cell itself” refers to a measurement over the entire cell without an aperture.
PDMS may be applied to the top glass sheet of a tandem, 4-terminal, silicon-perovskite solar module (i.e., the solar module 100 of
The PVD of the second TCO layer on the ETL can lead to defects in both the perovskite layer and the ETL in the tandem, 4-terminal, silicon-perovskite solar module (i.e., the solar module 100 of
As illustrated in
Table 3 further illustrates the increased performance of the solar module with the inclusion of the ultrathin silver layer. For example, with the silver layer, the solar module showed better efficiency, fill factor, open circuit voltage (Voc), short circuit voltage (Jsc), short circuit current (Isc), short circuit resistance (Rsc), and open circuit resistance (Roc).
As described herein, the 4-terminal, silicon-perovskite solar module (i.e., the solar module 100 of
Table 4 illustrates the increased efficiency of the solar modules fabricated in the inline manufacturing process. Table 4 points out (in bold text) specific scenarios where the solar module exhibited high efficiency, fill factor, and open circuit voltage due to the inline manufacturing process. Table 4 also illustrates that the inline manufacturing process was sufficiently effective in reducing defects to the ETL and perovskite layers such that the addition of the ultrathin layer of silver is not necessarily needed. As shown in Table 4, the ultrathin layer of silver did not provide for the same increase in efficiency as it did for solar modules not fabricated using the inline manufacturing process (e.g., compare the data in Table 4 to the data provided in Table 3 of Example 5).
In an example of a hybrid module, a six by ten array of silicon solar cells was electrically connected in series to form a silicon solar module with an open circuit voltage of 0.7 V×60=42 V. A perovskite layer was cut via laser scribe to form 40 strip solar cells. Each strip was about 20 mm wide by 300 mm long. The 40 strips were connected in series. Each strip had an open circuit voltage of 1.1 V, and the 40 series-connected strip may had a total voltage of 1.1 V×40=44V. To achieve full coverage of the silicon solar panel, five units of the 40 strip solar cells can be tiled on the same glass sheet. The units can in turn be connected in parallel to maintain the voltage matching condition. This can result in a substantially voltage matched hybrid module.
As described elsewhere herein, a perovskite layer (e.g., the perovskite layer 120 of
The high temperature aging plots of
Table 5 illustrates the performance of a thermally stable perovskite with a composition of Cs0.12FA0.88MA0.02PbCl0.01Br0.09I0.9. Despite being subjected to a relatively high temperature annealing operation, the perovskite solar cell was still able to maintain a high solar conversion efficiency of 18.64%. Such a high efficiency demonstrates the high stability that can be achieved in mixed composition perovskites.
Table 6 illustrates various parameters for perovskite solar cells with different types of edge sealing before a high temperature (e.g., >120° C.) encapsulation lamination process, directly after lamination, after an annealing operation at 100° C. for 10 minutes, and again after two days. The first column provides data for a perovskite solar cell with no edge sealing, while the middle column is for a perovskite solar cell with two edges sealed and the right column is for a perovskite solar cell with all four edges sealed. In each case, the perovskite solar cell was able to recover most, if not all, of the original efficiency after the annealing. Such thermal stability can permit use of higher quality, and higher temperature, encapsulation processes, which can in turn improve the longevity and efficiency of the solar cells.
A spray on precursor solution comprising lead (II) halides, methylammonium iodide, cesium, formamidinium iodide, dimethylformamide, dimethylsulfoxide, and N-methyl-2-pyrrolidone is formed as described elsewhere herein. For example, the precursors or salts thereof are mixed together, stirred, and slightly heated to improve homogeneity. The resultant precursor solution is applied to a substrate via an ultrasonic spray-on process and dried at room temperature for 5-15 minutes. The substrate with the precursor layer is then soaked in an antisolvent to form the perovskite layer. Examples of soaking include substrate dipping into the antisolvent, mechanical spraying of the antisolvent, chemical showering of the antisolvent, or the like, or any combination thereof. A slow addition of the perovskite film to the antisolvent may be effective in reducing defects in the film and residue left on the film. For example, a back and forth movement of the film during addition to an antisolvent bath can produce defects at the contact line between the film and the antisolvent. The substrates can be slowly introduced to the solvent bath to avoid such defects. Alternatively, a controlled pour rinse followed by a air knife dry can produce a high quality perovskite film.
Examples of antisolvent include, but are not limited to, diethyl ether, dibutyl ether, chlorobenzene, chloroform, or the like, or any combination thereof. Selection of the antisolvent may depend on miscibility of the antisolvent with the solvent (e.g., the solvent and antisolvent can be miscible), solubility of the perovskite in the antisolvent (e.g., the antisolvent may not effectively dissolve the perovskite), and the like. The quick removal of the solvent by way of the antisolvent may be important to the overall quality of the film. For example, if the antisolvent does not fully remove the solvent, an impenetrable skin can form on the top of the layer and inhibit further solvent removal. In another example, the quick removal of the solvent can result in a high quality film. The effluent from the soak can be recovered, refreshed (e.g., by removing solid particles), and reused for production of the next perovskite layer.
The perovskite layer is subsequently annealed as described elsewhere herein. For example, the perovskite layer can be annealed at a temperature between 90° C. and 110° C. for 5-15 minutes, and subsequently annealed at 110° C. for 10 minutes.
Such a method of producing a perovskite film can generate a perovskite solar cell with good performance and low hysteresis. Table 7 shows an example of the properties of an approximately 350 nm thick perovskite film made by this method.
An antisolvent free method of preparing perovskite layers may comprise utilization of a precursor solution comprising lead (II) acetate, lead (II) halide, methylammonium halide, and dimethylformamide. Such a solution may not use application of an antisolvent to form the perovskite layer. For example, the solution can be applied to a substrate and allowed to dry for 5-15 minutes at room temperature to form the perovskite layer. The perovskite layer may be subsequently annealed as described elsewhere herein.
Such methods may be scalable due to a combination of facile atmospheric controls (e.g., ambient conditions with low humidity), one-operation perovskite spray-on formulations, scalable drying processes (e.g., vacuum, air-knife, etc.), scalable annealing processes, and scalable electron transport layer addition (e.g., ultrasonic spray-on formulations and apparatuses).
The module can be tested to ensure that that the performance of the module will hold up over time. Such testing may comprise performance testing (e.g., performance measurements, temperature coefficient measurements, normal operating cell temperature measurements, low light irradiance performance, light induced degradation measurements, light and elevated temperature induced degradation measurements, etc.), environmental durability testing (e.g., temperature cycling, humidity freeze testing, damp heat testing, potential induced degradation testing, etc.), long term durability testing (e.g., outdoor exposure testing, hot spot testing, reverse current overload testing, UV conditioning, hail durability, etc.), or the like, or any combination thereof.
As described herein, IZTO can be used for one or both of the TCO layers.
Tables 8 and 9, below, respectively show a deposition recipe for IZTO layer optimization and the resulting transmission and sheet resistivity for the layers. In Table 8, the first row provides deposition parameters for a 250 nm thick layer of IZTO deposited at a power of 800 W. The second row provides deposition parameters for a 50 nm thick layer of IZTO at a power of 100 W.
Table 9 shows properties of resulting layers. “Bilayer” refers to a TCO layer formed from both a buffer layer (deposited at low power) and another layer (deposited at high power). Deposition parameters included power, % O2 and track speed. Transmission was measured at 700 nm, 800 nm, and 900 nm. Mean sheet resistance was also measured.
87.6
88.2
239
95.5
286
0
The present disclosure provides computer systems that are programmed to implement methods of the disclosure.
The computer system 1201 includes a central processing unit (CPU, also “processor” and “computer processor” herein) 1205, which can be a single core or multi core processor, or a plurality of processors for parallel processing. The computer system 1201 also includes memory or memory location 1210 (e.g., random-access memory, read-only memory, flash memory), electronic storage unit 1215 (e.g., hard disk), communication interface 1220 (e.g., network adapter) for communicating with one or more other systems, and peripheral devices 1225, such as cache, other memory, data storage and/or electronic display adapters. The memory 1210, storage unit 1215, interface 1220 and peripheral devices 1225 are in communication with the CPU 1205 through a communication bus (solid lines), such as a motherboard. The storage unit 1215 can be a data storage unit (or data repository) for storing data. The computer system 1201 can be operatively coupled to a computer network (“network”) 1230 with the aid of the communication interface 1220. The network 1230 can be the Internet, an internet and/or extranet, or an intranet and/or extranet that is in communication with the Internet. The network 1230 in some cases is a telecommunication and/or data network. The network 1230 can include one or more computer servers, which can enable distributed computing, such as cloud computing. The network 1230, in some cases with the aid of the computer system 1201, can implement a peer-to-peer network, which may enable devices coupled to the computer system 1201 to behave as a client or a server.
The CPU 1205 can execute a sequence of machine-readable instructions, which can be embodied in a program or software. The instructions may be stored in a memory location, such as the memory 1210. The instructions can be directed to the CPU 1205, which can subsequently program or otherwise configure the CPU 1205 to implement methods of the present disclosure. Examples of operations performed by the CPU 1205 can include fetch, decode, execute, and writeback.
The CPU 1205 can be part of a circuit, such as an integrated circuit. One or more other components of the system 1201 can be included in the circuit. In some cases, the circuit is an application specific integrated circuit (ASIC).
The storage unit 1215 can store files, such as drivers, libraries and saved programs. The storage unit 1215 can store user data, e.g., user preferences and user programs. The computer system 1201 in some cases can include one or more additional data storage units that are external to the computer system 1201, such as located on a remote server that is in communication with the computer system 1201 through an intranet or the Internet.
The computer system 1201 can communicate with one or more remote computer systems through the network 1230. For instance, the computer system 1201 can communicate with a remote computer system of a user. Examples of remote computer systems include personal computers (e.g., portable PC), slate or tablet PC's (e.g., Apple® iPad, Samsung® Galaxy Tab), telephones, Smart phones (e.g., Apple® iphone, Android-enabled device, Blackberry®), or personal digital assistants. The user can access the computer system 1201 via the network 1230.
Methods as described herein can be implemented by way of machine (e.g., computer processor) executable code stored on an electronic storage location of the computer system 1201, such as, for example, on the memory 1210 or electronic storage unit 1215. The machine executable or machine-readable code can be provided in the form of software. During use, the code can be executed by the processor 1205. In some cases, the code can be retrieved from the storage unit 1215 and stored on the memory 1210 for ready access by the processor 1205. In some situations, the electronic storage unit 1215 can be precluded, and machine-executable instructions are stored on memory 1210.
The code can be pre-compiled and configured for use with a machine having a processer adapted to execute the code or can be compiled during runtime. The code can be supplied in a programming language that can be selected to enable the code to execute in a pre-compiled or as-compiled fashion.
Aspects of the systems and methods provided herein, such as the computer system 1201, can be embodied in programming. Various aspects of the technology may be thought of as “products” or “articles of manufacture” typically in the form of machine (or processor) executable code and/or associated data that is carried on or embodied in a type of machine readable medium. Machine-executable code can be stored on an electronic storage unit, such as memory (e.g., read-only memory, random-access memory, flash memory) or a hard disk. “Storage” type media can include any or all of the tangible memory of the computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives and the like, which may provide non-transitory storage at any time for the software programming. All or portions of the software may at times be communicated through the Internet or various other telecommunication networks. Such communications, for example, may enable loading of the software from one computer or processor into another, for example, from a management server or host computer into the computer platform of an application server. Thus, another type of media that may bear the software elements includes optical, electrical and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links or the like, also may be considered as media bearing the software. As used herein, unless restricted to non-transitory, tangible “storage” media, terms such as computer or machine “readable medium” refer to any medium that participates in providing instructions to a processor for execution.
Hence, a machine readable medium, such as computer-executable code, may take many forms, including but not limited to, a tangible storage medium, a carrier wave medium or physical transmission medium. Non-volatile storage media include, for example, optical or magnetic disks, such as any of the storage devices in any computer(s) or the like, such as may be used to implement the databases, etc. shown in the drawings. Volatile storage media include dynamic memory, such as main memory of such a computer platform. Tangible transmission media include coaxial cables; copper wire and fiber optics, including the wires that comprise a bus within a computer system. Carrier-wave transmission media may take the form of electric or electromagnetic signals, or acoustic or light waves such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media therefore include for example: a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM, any other optical medium, punch cards paper tape, any other physical storage medium with patterns of holes, a RAM, a ROM, a PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave transporting data or instructions, cables or links transporting such a carrier wave, or any other medium from which a computer may read programming code and/or data. Many of these forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to a processor for execution.
The computer system 1201 can include or be in communication with an electronic display 1235 that comprises a user interface (UI) 1240 for providing, for example, control over fabrication process parameter. Examples of UI's include, without limitation, a graphical user interface (GUI) and web-based user interface.
Methods and systems of the present disclosure can be implemented by way of one or more algorithms. An algorithm can be implemented by way of software upon execution by the central processing unit 1205.
Certain embodiments of the invention are in the following numbered paragraphs.
1. A method for manufacturing a solar module, including: providing a first substrate including a substrate layer supporting a first electrically conducting layer and a hole transport layer on a first side of the glass layer; applying a perovskite precursor to the first side of the substrate; annealing the perovskite precursor to form a perovskite layer; applying an electron transport layer to the perovskite layer; and forming a second electrically conducting layer on the electron transport layer, the second electrically conducting layer being a transparent layer including IZTO.
2. The method of claim 1, wherein the second electrically conducting layer is formed using physical vapor deposition.
3. The method of paragraph 2, wherein forming the second electrically conducting layer including forming a buffer layer including IZTO on the perovskite layer under a first set of deposition conditions and forming a second layer of IZTO on the buffer layer under a second set of deposition conditions difference from the first set of deposition conditions.
4. The method of paragraph 3, wherein the first set of deposition conditions include a first power and the second set of deposition conditions include a second power higher than the first power.
5. The method of paragraph 4, wherein the physical vapor deposition is performed using a planar target and the first power is 1 W/cm2 or less (e.g., 0.9 W/cm2 or less, 0.8 W/cm2 or less, 0.7 W/cm2 or less, 0.6 W/cm2 or less, 0.5 W/cm2 or less, 0.4 W/cm2 or less, 0.3 W/cm2 or less, e.g., 0.1 W/cm2 or more, 0.2 W/cm2 or more) and the second power is 1.5 W/cm2 or more (e.g., 1.6 W/cm2 or more, 1.7 W/cm2 or more, 1.8 W/cm2 or more, 1.9 W/cm2 or more, 2 W/cm2 or more, 2.1 W/cm2 or more, 2.2 W/cm2 or more, 2.3 W/cm2 or more, 2.4 W/cm2 or more, 2.5 W/cm2 or more, e.g., 5 W/cm2 or less, 4 W/cm2 or less, 3 W/cm2 or less, 2.5 W/cm2 or less) or the physical vapor deposition is performed using a rotary target and the first power is 3 kW/m or less (e.g., 2.5 kW/m or less, 2.3 kW/m or less, 2 kW/m or less, 1.8 kW/m or less, 1.5 kW/m or less, 1.3 kW/m or less, 1 kW/m or less, e.g., 0.5 kW/m or more, 0.7 kW/m or more, 1 kW/m or more) and the second power is 5 kW/m or more (e.g., 6 kW/m or more, 7 kW/m or more, 8 kW/m or more, 9 kW/m or more, 10 kW/m or more, 12 kW/m or more, 15 kW/m or more, 18 kW/m or more, 20 kW/m or more, e.g., 30 kW/m or less, 25 kW/m or less, 22 kW/m or less, 20 kW/m or less).
6. The method of paragraph 5, wherein the first power is about 0.5 W/cm2.
7. The method of paragraph 5, wherein the second power is about 2 W/cm2.
8. The method of paragraph 3, wherein the buffer layer has a thickness of 100 nm or less.
9. The method of paragraph 8, wherein the buffer layer has a thickness in a range from 40 nm to 60 nm.
10. The method of paragraph 3, wherein the second layer of IZTO has a thickness of 100 nm or more.
11. The method of paragraph 10, wherein the second layer of IZTO has a thickness in a range from 200 nm to 300 nm.
12. The method of paragraph 1, wherein the second electrically conducting layer is formed while maintaining the perovskite layer at a temperature of 120 degrees Celsius or less.
13. The method of paragraph 12, wherein the second electrically conducting layer is formed while maintaining the perovskite layer at room temperature.
14. The method of paragraph 1, wherein the second electrically conducting layer consists essentially of IZTO.
15. The method of paragraph 1, wherein the second electrically conducting layer has a transmission at 700 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light.
16. The method of paragraph 1, wherein the second electrically conducting layer has a mean resistivity of 35 Ohm/sq. or less (e.g., 34 Ohm/sq. or less, 32 Ohm/sq. or less, 30 Ohm/sq. or less, 28 Ohm/sq. or less, 26 Ohm/sq. or less, 24 Ohm/sq. or less, e.g., 20 Ohm/sq. or more, 22 Ohm/sq. or more, 24 Ohm/sq. or more, 25 Ohm/sq. or more).
17. The method of paragraph 1, wherein the second electrically conducting layer has a transmission at 700 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light and the second electrically conducting layer has a mean resistivity of 35 Ohm/sq. or less (e.g., 34 Ohm/sq. or less, 32 Ohm/sq. or less, 30 Ohm/sq. or less, 28 Ohm/sq. or less, 26 Ohm/sq. or less, 24 Ohm/sq. or less, e.g., 20 Ohm/sq. or more, 22 Ohm/sq. or more, 24 Ohm/sq. or more, 25 Ohm/sq. or more).
18. The method of paragraph 1, further including forming one or more busbars on the second electrically conducting layer.
19. The method of paragraph 1, wherein fabricating the active glass layer further includes applying an encapsulant to the second transparent conducting layer.
20. The method of paragraph 19, wherein the encapsulant includes a polymer or a wax.
21. The method of paragraph 19, wherein the encapsulant is applied to a surface of the second transparent conducting layer and to edges of one or more of the layer between the glass layer and the second transparent conducting layer.
22. The method of paragraph 1, wherein the perovskite layer has a band gap in a range from 1.6 eV to 2.0 eV.
23. The method of paragraph 1, wherein the perovskite layer includes a compound having the chemical formula MAn1FAn2CSn3PbX3, wherein MA is methylammonium, FA is formamidinium, X is selected from the group consisting of fluorine, chlorine, bromine, and iodine, n1, n2, and n3 are independently greater than 0 and less than 1, and n1+n2+n3=1.
24. The method of paragraph 23, wherein n1 is from about 0.001 to 0.99, n2 is from about 0.001 to 0.99, and n3 is from about 0.005 to 0.5.
25. The method of paragraph 23, wherein the perovskite layer includes CH3NH3PbX3 or H2NCHNH2PbX3.
26. The method of paragraph 1, wherein the electron transport layer includes a compound selected from the group consisting of titanium oxide, zinc oxide, tin oxide, tungsten oxide, indium oxide, niobium oxide, iron oxide, cerium oxide, strontium titanium oxide, zinc tin oxide, barium tin oxide, cadmium selenide, indium sulfide, lead iodide, phenyl-C61-butyric acid methyl ester (PCBM), poly(3-hexylthiophene-2,5-diyl) (P3HT), lithium fluoride, and fullerenes.
27. The method of paragraph 1, wherein the substrate layer is a glass layer.
28. The method of paragraph 27, further including attaching an active glass layer including the glass layer, first electrically conducting layer, hole transport layer, perovskite layer, and second electrically conducting layer to a silicon panel to form a tandem solar module, the silicon panel including a second substrate and a silicon layer supported by the second substrate.
29. The method of paragraph 28, wherein the perovskite layer and the silicon layer are arranged in the tandem solar cell between the glass layer and the second substrate.
30. The method of paragraph 28, wherein attaching the active glass layer to the silicon panel includes laminating the active glass layer to the silicon panel.
31. The method of paragraph 30, wherein the lamination is performed at a temperature in a range from 100° C. to 150° C.
32. The method of paragraph 28, wherein the perovskite layer has a first band gap and the silicon layer has a second band gap different from the first band gap.
33. The method of paragraph 1, wherein the solar module includes a layer of polydimethyl siloxane (PDMS).
34. The method of paragraph 1, wherein applying the perovskite precursor includes coating a layer of the perovskite precursor on the first side of the substrate.
35. The method of paragraph 34, wherein the coating includes blade-coating, slot-die coating, spin coating, dip coating, doctor blading, drop casting, or centrifugal casting the perovskite precursor on the first side of the substrate.
36. The method of paragraph 1, wherein the first electrically conducting layer includes IZTO.
37. The method of paragraph 36, wherein the first electrically conducting layer consists essentially of IZTO.
38. The method of paragraph 1, wherein the second electrically conducting layer is formed using a target including indium tin zinc.
39. The method of paragraph 38, wherein the target is a metallic target.
40. A solar module, including: a substrate; a first electrically conducting layer supported on the substrate layer on a first side of the substrate; a hole transport layer supported on the first electrically conducting layer; a perovskite layer supported on the hole transport layer; an electron transport layer supported on the perovskite layer; and a second electrically conducting layer supported on the electron transport layer, the second electrically conducting layer being a transparent layer including IZTO.
41. The solar module of paragraph 40, wherein the second electrically conducting layer consists essentially of IZTO.
42. The solar module of paragraph 40, wherein the second electrically conducting layer has a thickness in a range from 100 nm to 1,000 nm.
43. The solar module of paragraph 42, wherein the thickness is in the range from 300 nm to 500 nm.
44. The solar module of paragraph 40, wherein the second electrically conducting layer has a transmission at 700 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light.
45. The solar module of paragraph 40, wherein the second electrically conducting layer has a mean resistivity of 35 Ohm/sq. or less (e.g., 34 Ohm/sq. or less, 32 Ohm/sq. or less, 30 Ohm/sq. or less, 28 Ohm/sq. or less, 26 Ohm/sq. or less, 24 Ohm/sq. or less, e.g., 20 Ohm/sq. or more, 22 Ohm/sq. or more, 24 Ohm/sq. or more, 25 Ohm/sq. or more).
46. The solar module of paragraph 40, wherein the second electrically conducting layer has a transmission at 700 nm or 80% or more (e.g., 82% or more, 85% or more, 88% or more, 90% or more, 92% or more, 95% or more, 96% or more, 97% or more, 98% or more, e.g., 99% or less) for normally incident light and the second electrically conducting layer has a mean resistivity of 35 Ohm/sq. or less (e.g., 34 Ohm/sq. or less, 32 Ohm/sq. or less, 30 Ohm/sq. or less, 28 Ohm/sq. or less, 26 Ohm/sq. or less, 24 Ohm/sq. or less, e.g., 20 Ohm/sq. or more, 22 Ohm/sq. or more, 24 Ohm/sq. or more, 25 Ohm/sq. or more).
47. The solar module of paragraph 40, further including busbars supported on the second electrically conducting layer.
48. The solar module of paragraph 40, further including an encapsulant supported on the second electrically conducting layer.
49. The solar module of paragraph 48, wherein the encapsulant includes a polymer or a wax.
50. The solar module of paragraph 40, wherein the perovskite layer has a band gap in a range from 1.6 eV to 2.0 eV.
51. The solar module of paragraph 40, wherein the perovskite layer includes a compound having the chemical formula MAn1FAn2CSn3PbX3, wherein MA is methylammonium, FA is formamidinium, X is selected from the group consisting of fluorine, chlorine, bromine, and iodine, n1, n2, and n3 are independently greater than 0 and less than 1, and n1+n2+n3=1.
52. The solar module of paragraph 51, wherein n1 is from about 0.001 to 0.99, n2 is from about 0.001 to 0.99, and n3 is from about 0.005 to 0.5.
53. The solar module of paragraph 40, wherein the perovskite layer includes CH3NH3PbX3 or H2NCHNH2PbX3.
54. The solar module of paragraph 40, wherein the electron transport layer includes a compound selected from the group consisting of titanium oxide, zinc oxide, tin oxide, tungsten oxide, indium oxide, niobium oxide, iron oxide, cerium oxide, strontium titanium oxide, zinc tin oxide, barium tin oxide, cadmium selenide, indium sulfide, lead iodide, phenyl-C61-butyric acid methyl ester (PCBM), poly(3-hexylthiophene-2,5-diyl) (P3HT), lithium fluoride, and fullerenes.
55. The solar module of paragraph 40, wherein the substrate layer is a glass layer.
56. The solar module of paragraph 55, further including a silicon panel and the solar module is a tandem solar module.
57. The solar module of paragraph 56, wherein the perovskite layer and the silicon layer are arranged in the tandem solar cell between the glass layer and a second substrate.
58. The solar module of paragraph 40, wherein the first electrically conducting layer includes IZTO.
59. The solar module of paragraph 58, wherein the first electrically conducting layer consists essentially of IZTO.
60. The solar module of paragraph 40, wherein the solar module is a transparent solar technology device.
While certain embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the invention be limited by the specific examples provided within the specification. While the invention has been described with reference to the aforementioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Furthermore, it shall be understood that all aspects of the invention are not limited to the specific depictions, configurations or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is therefore contemplated that the invention shall also cover any such alternatives, modifications, variations or equivalents. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
This application claims the benefit of priority to U.S. Application No. 63/603,312, filed on Nov. 28, 2023, the contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63603312 | Nov 2023 | US |
