Use of photovoltaics (PVs) to generate electrical power from solar energy or radiation may provide many benefits, including, for example, a power source, low or zero emissions, power production independent of the power grid, durable physical structures (no moving parts), stable and reliable systems, modular construction, relatively quick installation, safe manufacture and use, and good public opinion and acceptance of use.
Portions of PVs may be susceptible to halide phase segregation upon sunlight radiation. PVs may function better if protected from moisture that leads to degradation and lack of performance.
The features and advantages of the present disclosure will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the invention.
According to some embodiments, a photovoltaic device includes a first electrode, a first photoactive material layer, one or more interfacial layers, a second photoactive material layer comprising a 2-D perovskite material having the formula (C′)a(C)bMnX3n+1 and a second electrode. C′ is a bulky organic cation, C is a small organic or inorganic cation, M is a metal, X is a halide, a and b are real numbers, and n is an integer.
According to some embodiments, a photovoltaic device includes a first electrode, an interfacial layer, a second electrode, a first photoactive material layer selected from the group consisting of perovskite, silicon, CdTe, CIGS, GaAs, InP, and Ge, a second photoactive material layer comprising a 2-D perovskite material having the formula (C′)a(C)bMnX3n+1. C′ is a bulky organic cation, C is a small organic or inorganic cation, M is a metal, X is a halide or pseudohalide, a and b are real numbers, and n is an integer. The first photoactive material is positioned between the first electrode and the interfacial layer. The second photoactive material layer is positioned between the interfacial layer and the second electrode.
Improvements in various aspects of PV technologies compatible with organic, non-organic, and/or hybrid PVs promise to further lower the cost of both organic PVs and other PVs. For example, some solar cells, such as perovskite PV solar cells, may take advantage of novel cost-effective and high-stability alternative components, such as nickel oxide interfacial layers. In addition, various kinds of solar cells may advantageously include chemical additives and other materials that may, among other advantages, be more cost-effective and durable than conventional options currently in existence.
The present disclosure relates generally to compositions of matter of use in creating electrical energy from solar radiation. More specifically, this disclosure relates to photoactive and other compositions of matter.
Some or all of materials in accordance with some embodiments of the present disclosure may also advantageously be used in any organic or other electronic device, with some examples including, but not limited to: batteries, field-effect transistors (FETs), light-emitting diodes (LEDs), non-linear optical devices, memristors, capacitors, rectifiers, and/or rectifying antennas.
Metal halides in perovskites present a versatile class of solution-processable semiconductors with excellent optoelectronic properties. The use of metal halides in tandem solar cells has been demonstrated in literature in which c-Si or three-dimensional (3D) perovskites serve as the bottom-cell and 3D perovskites serve as the top-cell. Perovskite-containing tandem solar cells reported thus far employ 3D lead iodide mixed with bromide to achieve the desired top-cell optical band gap of around 1.7 eV. However, mixed halide anions have been shown to be intrinsically unstable such that upon continuous irradiation they segregate into iodide- and bromide-phases which detrimentally affects the light harvesting efficiency of the top cell. Thus, there is a need for an improved solution.
This disclosure provides a tandem solar cell device architecture where a cell made from two-dimensional (2D) metal halide perovskites, is monolithically stacked on top of the bottom-cell, made from, for example c-Si (in a 2- or 3-terminal design) or mechanically stacked on top of the bottom-cell (in a 4-terminal design).
In some embodiments, the present disclosure may provide PV and other similar devices (e.g., batteries, hybrid PV batteries, multi junction PVs, FETs, LEDs, x-ray detectors, gamma ray detectors, photodiodes, CCDs, etc.). Such devices may in some embodiments include improved active material, interfacial layers (IFLs), and/or one or more perovskite materials. A perovskite material may be incorporated into various of one or more aspects of a PV or other device. A 2D perovskite material according to some embodiments may be of the general formula (C′)a(C)bMnX3n+1, wherein C′ is a bulky organic cation, C is a smaller organic or inorganic cation, M is a divalent metal, X is a halide or pseudohalide, a and b are real numbers, and n is an integer. In other embodiments, M may be a combination of monovalent and trivalent metals and may be written in the form M′M″ where M′ is a monovalent metal and M″ is a trivalent metal. In such embodiments, the ratio of monovalent metal to trivalent metal may range from 1:99 to 50:50, and in particular embodiments, may be 1:99, 25:75; or 50:50.
As illustrated in
In general, tandem photovoltaic cells, “tandem PVs,” include two photoactive layers. One photoactive layer generally is a material that has a wider band gap than the material that makes up the other photoactive layer. The wider band gap photoactive material, such as a 2D perovskite of the present disclosure, is situated closest to the sun-facing side of the PV cell and collects short wave length radiation more efficiently than the narrower band gap photoactive material. The narrower band gap material, such as silicon, CdTe, or non-2D perovskite, is more efficient at absorbing longer wavelength light that is not absorbed by the wider bandgap photoactive material. This disclosure identifies the potential choices for C′, C, M, X, and the n value to achieve an optical band gap of 1.70-1.90 eV for the top cell, in some embodiments, as well as improving the long-term stability of, for example, Si/perovskite tandem solar cells. The bandgap may be tailored for the properties of the bottom cells, in cases such as CdTe/perovskite, CIGS/perovskite, GaAs/perovskite, InP/perovskite, Ge/perovskite, perovskite/perovskite, PbS/perovskite, amongst others. In certain embodiments, n is a value between 1 and 10, and in particular embodiments between 3 and 4, X is iodide, M is lead, C is cesium, methylammonium (MA) or formamidinium (FA), and C′ is one of benzylammonium, phenylethylammonium, n-butylammonium, iminomethanediammonium, and a cation of 4-(aminomethyl)piperidine.
Two-dimensional lead iodide perovskite compounds, like the compounds described in some embodiments of this disclosure, substantially contain a single type of anion (e.g. only a single species of halide or pseudohalide such as only thiocyanate, only iodide, only bromide, or only chloride) with no more than trace amounts of other species. Thus, they will not undergo halide phase segregation upon sunlight irradiation, unlike the mixture of iodide and bromide currently used in the state-of-the-art Si/perovskite and perovskite/perovskite tandem solar cells. Thus, this disclosure contemplates systems consisting substantially of of iodide, bromide or chloride.
Photovoltaic Cells and Other Electronic Devices
Some PV embodiments may be described by reference to the illustrative depictions of solar cells as shown in
Referring to
Additionally, the architectures exhibited in
The PV cell 1000 includes two electrically conductive electrode layers, a first electrode layer 1021 and a second electrode layer 1022. Electrode layers 1021 and 1022 may be transparent conductors such as tin-doped indium oxide (ITO) or any other material as described herein. In other embodiments, electrode layers 1021 and 1022 may be a metal, such as aluminum, or other conducive material such as carbon. PV cell 1000 also includes interfacial layers (IFL) 1031, 1032, and 1033. IFLs 1031, 1032, and 1033 may assist in charge recombination. In some embodiments, each IFL layer may be a multi-layer IFL, which is discussed in greater detail herein. In particular embodiments, IFL 1032 may be a multi-layer recombination layer IFL, such as one of the IFLs illustrated by
PV cells 1000, 2000, and 3000 of
In certain embodiments, photoactive material may instead or in addition comprise a dye (e.g., N719, N3, other ruthenium-based dyes). In some embodiments, a dye (of whatever composition) may be coated onto another layer (e.g., a mesoporous layer and/or an interfacial layer). In some embodiments, photoactive material may include one or more perovskite materials. Perovskite-material-containing photoactive substance may be of a solid form, or in some embodiments it may take the form of a dye that includes a suspension or solution comprising perovskite material. Such a solution or suspension may be coated onto other device components in a manner similar to other dyes. In some embodiments, solid perovskite-containing material may be deposited by any suitable means (e.g., vapor deposition, solution deposition, direct placement of solid material). Devices according to various embodiments may include one, two, three, or more photoactive compounds (e.g., one, two, three, or more perovskite materials, dyes, or combinations thereof). In certain embodiments including multiple dyes or other photoactive materials, each of the two or more dyes or other photoactive materials may be separated by one or more interfacial layers. In some embodiments, multiple dyes and/or photoactive compounds may be at least in part intermixed.
PV cell 1000 may be attached to electrical leads by electrodes 1021 and 1022, which may connect PV cell 1000 to a discharge unit, such as a battery, motor, capacitor, electric grid, or any other electrical load. An electrode may constitute any conductive material, and at least one electrode should be transparent or translucent to EM radiation, and/or be arranged in a manner that allows EM radiation to contact at least a portion of the active layers of device 1000. Suitable electrode materials may include any one or more of: indium tin oxide or tin-doped indium oxide (ITO); fluorine-doped tin oxide (FTO); cadmium oxide (CdO); zinc indium tin oxide (ZITO); aluminum zinc oxide (AZO); aluminum (Al); gold (Au); silver (Ag); calcium (Ca); chromium (Cr); magnesium (Mg); titanium (Ti); steel; carbon (and allotropes thereof); doped carbon (e.g., nitrogen-doped); nanoparticles in core-shell configurations (e.g., silicon-carbon core-shell structure); and combinations thereof. In some embodiments, an electrode may be a grid, web, or mesh of any of the forgoing materials. Grid, web, or mesh electrodes may provide for transparency of the electrodes when constructed of materials that would not otherwise be transparent. For example, metal electrodes of a recombination IFL, such as electrode 1913 of
As with PV cell 1000 and PV cell 2000 illustrated in
In certain embodiments, at least one IFL, electrode, substrate, and photoactive layer must be transparent to light having a wavelength greater than 500 nanometers to allow light to reach the second photoactive layer.
Additionally, while the discussion in this disclosure is primarily directed to tandem PV cells having two photoactive layers, the general principles described herein may apply to a PV cell with more than two photoactive layers. For example,
Any suitable substrate, electrode, IFL, or photoactive material described herein may be implemented as the respective layers of PV device 2100.
The PV cell 1000 also includes a first photoactive layer 1041. First photoactive layer 1041 may include a first photoactive material. In certain embodiments, the first photoactive material may be a 2-D perovskite material having the formula (C′)a(C)bMnX3n+1, wherein C′ is a bulky organic cation, C is a small organic or inorganic cation, M is a divalent metal, X is a halide or pseudohalide, and a and b are real numbers, and n is an integer. In other embodiments, M may be a combination of monovalent and trivalent metals and may be written in the form M′M″ where M′ is a monovalent metal and M″ is a trivalent metal. In such embodiments, the ratio of monovalent metal to trivalent metal may range from 1:99 to 50:50, and in particular embodiments, may be 1:99, 25:75; or 50:50. As illustrated in
Examples of other “bulky organic” organic cations that may function as C′, include, but are not limited to, ethylammonium, propylammonium, n-butylammonium; perylene n-butylamine-imide; butane-1,4-diammonium; 1-pentylammonium; 1-hexylammonium; poly(vinylammonium); phenylethylammonium; 3-phenyl-1-propylammonium; 4-phenyl-1-butylammonium; 1,3-dimethylbutylammonium; 3,3-dimethylbutylammonium; 1-heptylammonium; 1-octylammonium; 1-nonylammonium; 1-decylammonium; and 1-eicosanyl ammonium. Additionally, bulky organic cations with a tail that contains one or more heteroatoms in addition to the cationic species, the heteroatom may coordinate with, bind to, or integrate with the perovskite material crystal lattice. A heteroatom may be any atom in the tail that is not hydrogen or carbon, including boron, nitrogen, sulfur, oxygen, or phosphorous.
Other examples of bulky organic cations may include the following molecules functionalized with an ammonium group, phosphonium group, or other cationic group that may integrate into a surface C-site of a perovskite material: benzene, pyridine, naphthalene, anthracene, xanthene, phenanthrene, tetracene chrysene, tetraphene, benzo[c]phenathrene, triphenylene, pyrene, perylene, corannulene, coronene, substituted dicarboxylic imides, aniline, N-(2-aminoethyl)-2-isoindole-1,3-dione, 2-(1-aminoethyl)naphthalene, 2-triphenylene-O-ethyl amine ether, benzylamine, benzylammonium salts, N-n-butyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 1-(4-alkylphenyl)methanamine, 1-(4-alkyl-2-phenyl)ethanamine, 1-(4-alkylphenyl)methanamine, 1-(3-alkyl-5-alkylphenyl)methanamine, 1-(3-alkyl-5-alkyl-2-phenyl)ethanamine, 1-(4-alkyl-2-phenyl)ethanamine, 2-Ethylamine-7-alkyl-Naphthalene, 2-Ethylamine-6-alkyl-Naphthalene, 1-Ethylamine-7-alkyl-Naphthalene, 1-Ethylamine-6-alkyl-Naphthalene, 2-Methylamine-7-alkyl-Naphthalene, 2-Methylamine-6-alkyl-Naphthalene, 1-Methylamine-7-alkyl-Naphthalene, 1-Methylamine-6-alkyl-Naphthalene, N-n-aminoalkyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 1-(3-Butyl-5-methoxybutylphenyl)methanamine, 1-(4-Pentylphenyl)methanamine, 1-[4-(2-Methylpentyl)-2-phenyl]ethanamine, 1-(3-Butyl-5-pentyl-2-phenyl)ethanamine, 2-(5-[4-Methylpentyl]-2-naphthyl)ethanamine, N-7-tridecyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), N-n-heptyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 2-(6-[3-Methoxyl propyl]-2-naphthyl)ethanamine.
In certain embodiments, the first photoactive material may be a material with an optical band gap between approximately 1.7 eV and 1.9 eV. The first photoactive material may be an electron donor (p-type) material, and/or an electron acceptor (n-type) material, and/or an ambipolar semiconductor, which exhibits both p- and n-type material characteristics, and/or an intrinsic semiconductor which exhibits neither n-type nor p-type characteristics.
The PV cell 1000 also includes a second photoactive layer 1042. The second photoactive layer includes a second photoactive material. In certain embodiments, the second photoactive material is selected from the group consisting of perovskite, PbS, silicon, CdTe, CIGS, GaAs, InP, and Ge. In other embodiments, the second photoactive material may be selected from any one or more of perovskite (for example, FAPbI3, FASnI3, MASnI3, or CsSnI3), silicon (for example, polycrystalline silicon, single-crystalline silicon, or amorphous silicon), cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, copper indium selenide, copper zinc tin sulfide, gallium arsenide, germanium, germanium indium phosphide, indium phosphide, lead sulfide, one or more semiconducting polymers (e.g., polythiophenes (e.g., poly(3-hexylthiophene) and derivatives thereof, or P3HT); carbazole-based copolymers such as polyheptadecanylcarbazole dithienylbenzothiadiazole and derivatives thereof (e.g., PCDTBT); other copolymers such as polycyclopentadithiophene-benzothiadiazole and derivatives thereof (e.g., PCPDTBT), polybenzodithiophenyl-thienothiophenediyl and derivatives thereof (e.g., PTB6, PTB7, PTB7-th, PCE-10); poly(triaryl amine) compounds and derivatives thereof (e.g., PTAA); polyphenylene vinylenes and derivatives thereof (e.g., MDMO-PPV, MEH-PPV), and combinations thereof. In some embodiments, photoactive layer 1042, IFL 1033, electrode layer 1022 and substrate 1012 may formed from a monolithic substrate material. For example, photoactive layer 1042, IFL 1033, electrode layer 1022 and substrate 1012 may be regions of a silicon substrate that have each been doped or reacted to create layers within the silicon substrate with the desired properties. In certain embodiments, the second photoactive layer 1042 may include additional layers. In certain embodiments, the second photoactive layer may be less than 200 microns thick. In certain embodiments, the second photoactive material is a patterned substrate. A patterned substrate, created by etching or texturing the second substrate layer, increases refraction and thus increases the light path length to increase the efficiency of the second photoactive layer 1042. In certain embodiments, the second photoactive material has an optical band gap of approximately 1.1 eV. The second photoactive material may be an electron donor (p-type) material, and/or an electron acceptor (n-type) material, and/or an ambipolar semiconductor, which exhibits both p- and n-type material characteristics, and/or an intrinsic semiconductor which exhibits neither n-type nor p-type characteristics.
In certain embodiments, first photoactive layer 1041 and second photoactive layer 1042 may be complete PV cells that would otherwise function independently of each other. However, when combined via a recombination layer (e.g. IFL 1032) and/or one or more shared electrodes (e.g. electrode layer 2022 of
Various embodiments of the present disclosure provide improved materials and/or designs in various aspects of solar cell and other devices, including among other things, active materials (including hole-transport and/or electron-transport layers), interfacial layers, and overall device design.
Interfacial Layers
The present disclosure, in some embodiments, provides advantageous materials and designs of one or more IFLs within a PV.
According to various embodiments, devices may optionally include an interfacial layer between any two other layers and/or materials, although devices need not contain any interfacial layers. For example, a photovoltaic device may contain zero, one, two, three, four, five, or more interfacial layers. An interfacial layer may include any suitable material for enhancing charge transport and/or collection between two layers or materials; it may also help prevent or reduce the likelihood of charge recombination once a charge has been transported away from one of the materials adjacent to the interfacial layer. In other embodiments, such as the interfacial layers illustrated in
An interfacial layer may additionally physically and electrically homogenize its substrates to create variations in substrate roughness, dielectric constant, adhesion, creation or quenching of defects (e.g., charge traps, surface states). Suitable interfacial materials may include any one or more of: Ag; Al; Au; B; Bi; Ca; Cd; Ce; Co; Cu; Fe; Ga; Ge; H; In; Mg; Mn; Mo; Nb; Ni; Pt; Sb; Sc; Si; Sn; Ta; Ti; V; W; Y; Zn; Zr; carbides of any of the foregoing metals (e.g., SiC, Fe3C, WC, VC, MoC, NbC); silicides of any of the foregoing metals (e.g., Mg2Si, SrSi2, Sn2Si); oxides of any of the foregoing metals (e.g., alumina, silica, titania, SnO2, ZnO, NiO, ZrO2, HfO2), include transparent conducting oxides (“TCOs”) such as indium tin oxide, aluminum doped zinc oxide (AZO), cadmium oxide (CdO), and fluorine doped tin oxide (FTO); sulfides of any of the foregoing metals (e.g., CdS, MoS2, SnS2); nitrides of any of the foregoing metals (e.g., GaN, Mg3N2, TiN, BN, Si3N4); selenides of any of the foregoing metals (e.g., CdSe, FeS2, ZnSe); tellurides of any of the foregoing metals (e.g., CdTe, TiTe2, ZnTe); phosphides of any of the foregoing metals (e.g., InP, GaP, GaInP); arsenides of any of the foregoing metals (e.g., CoAs3, GaAs, InGaAs, NiAs); antimonides of any of the foregoing metals (e.g., AlSb, GaSb, InSb); halides of any of the foregoing metals (e.g., CuCl, CuI, BiI3); pseudohalides of any of the foregoing metals (e.g., CuSCN, AuCN, Fe(SCN)2); carbonates of any of the foregoing metals (e.g., CaCO3, Ce2(CO3)3); functionalized or non-functionalized alkyl silyl groups; graphite; graphene; fullerenes; carbon nanotubes; any mesoporous material and/or interfacial material discussed elsewhere herein; and combinations thereof (including, in some embodiments, bilayers, trilayers, or multi-layers of combined materials). In some embodiments, an interfacial layer may include perovskite material. Further, interfacial layers may comprise doped embodiments of any interfacial material mentioned herein (e.g., Y-doped ZnO, N-doped single-wall carbon nanotubes). Interfacial layers may also comprise a compound having three of the above materials (e.g., CuTiO3, Zn2SnO4) or a compound having four of the above materials (e.g., CoNiZnO). The materials listed above may be present in a planar, mesoporous or otherwise nano-structured form (e.g. rods, spheres, flowers, pyramids), or aerogel structure.
First, as previously noted, one or more IFLs (e.g., IFL 1030 as shown in
Metal oxides may be used in thin film IFLs of some embodiments and may include semiconducting metal oxides, such as NiO, SnO2, WO3, V2O5, or MoO3. The embodiment wherein the second (e.g., n-type) active material comprises TiO2 coated with a thin-coat IFL comprising Al2O3 could be formed, for example, with a precursor material such as Al(NO3)3.xH2O, or any other material suitable for depositing Al2O3 onto the TiO2, followed by thermal annealing and dye coating. In example embodiments wherein a MoO3 coating is instead used, the coating may be formed with a precursor material such as Na2Mo4.2H2O; whereas a V2O5 coating according to some embodiments may be formed with a precursor material such as NaVO3; and a WO3 coating according to some embodiments may be formed with a precursor material such as NaWO4.H2O. The concentration of precursor material (e.g., Al(NO3)3.xH2O) may affect the final film thickness (here, of Al2O3) deposited on the TiO2 or other active material. Thus, modifying the concentration of precursor material may be a method by which the final film thickness may be controlled. For example, greater film thickness may result from greater precursor material concentration. Greater film thickness may not necessarily result in greater PCE in a PV device comprising a metal oxide coating. Thus, a method of some embodiments may include coating a TiO2 (or other mesoporous) layer using a precursor material having a concentration in the range of approximately 0.5 to 10.0 mM; other embodiments may include coating the layer with a precursor material having a concentration in the range of approximately 2.0 to 6.0 mM; or, in other embodiments, approximately 2.5 to 5.5 mM.
Furthermore, although referred to herein as Al2O3 and/or alumina, it should be noted that various ratios of aluminum and oxygen may be used in forming alumina. Thus, although some embodiments discussed herein are described with reference to Al2O3, such description is not intended to define a required ratio of aluminum in oxygen. Rather, embodiments may include any one or more aluminum-oxide compounds, each having an aluminum oxide ratio according to AlxOy, where x may be any value, integer or non-integer, between approximately 1 and 100. In some embodiments, x may be between approximately 1 and 3 (and, again, need not be an integer). Likewise, y may be any value, integer or non-integer, between 0.1 and 100. In some embodiments, y may be between 2 and 4 (and, again, need not be an integer). In addition, various crystalline forms of AlxOy may be present in various embodiments, such as alpha, gamma, and/or amorphous forms of alumina.
Likewise, although referred to herein as NiO, MoO3, WO3, and V2O5, such compounds may instead or in addition be represented as NixOy MoxOy, WxOy, and VxOy, respectively. Regarding each of MoxOy and WxOy, x may be any value, integer or non-integer, between approximately 0.5 and 100; in some embodiments, it may be between approximately 0.5 and 1.5. Likewise, y may be any value, integer or non-integer, between approximately 1 and 100. In some embodiments, y may be any value between approximately 1 and 4. Regarding VxOy, x may be any value, integer or non-integer, between approximately 0.5 and 100; in some embodiments, it may be between approximately 0.5 and 1.5. Likewise, y may be any value, integer or non-integer, between approximately 1 and 100; in certain embodiments, it may be an integer or non-integer value between approximately 1 and 10. In some embodiments, x and y may have values so as to be in a non-stoichiometric ratio.
In some embodiments, the IFL may comprise a titanate. A titanate according to some embodiments may be of the general formula M′TiO3, where M′ comprises any 2+ cation. In some embodiments, M′ may comprise a cationic form of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In some embodiments, the IFL may comprise a single species of titanate, which in other embodiments, the IFL may comprise two or more different species of titanates. In one embodiment, the titanate has the formula SrTiO3. In another embodiment, the titanate may have the formula BaTiO3. In yet another embodiment, the titanate may have the formula CaTiO3.
By way of explanation, and without implying any limitation, titanates have a perovskite crystalline structure and strongly seed the perovskite material (e.g., MAPbI3, FAPbI3) growth conversion process. Titanates generally also meet other IFL requirements, such as ferroelectric behavior, sufficient charge carrier mobility, optical transparency, matched energy levels, and high dielectric constant.
In other embodiments, the IFL may comprise a zirconate. A zirconate according to some embodiments may be of the general formula M′ZrO3, where M′ comprises any 2+ cation. In some embodiments, M′ may comprise a cationic form of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In some embodiments, the IFL may comprise a single species of zirconate, which in other embodiments, the IFL may comprise two or more different species of zirconate. In one embodiment, the zirconate has the formula SrZrO3. In another embodiment, the zirconate may have the formula BaZrO3. In yet another embodiment, the zirconate may have the formula CaZrO3.
By way of explanation, and without implying any limitation, zirconates have a perovskite crystalline structure and strongly seed the perovskite material (e.g., MAPbI3, FAPbI3) growth conversion process. Zirconates generally also meet other IFL requirements, such as ferroelectric behavior, sufficient charge carrier mobility, optical transparency, matched energy levels, and high dielectric constant.
In other embodiments, the IFL may comprise a stannate. A stannate according to some embodiments may be of the general formula M′ SnO3, or M′2SnO4 where M′ comprises any 2+ cation. In some embodiments, M′ may comprise a cationic form of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In some embodiments, the IFL may comprise a single species of stannate, which in other embodiments, the IFL may comprise two or more different species of stannate. In one embodiment, the stannate has the formula SrSnO3. In another embodiment, the stannate may have the formula BaSnO3. In yet another embodiment, the stannate may have the formula CaSnO3.
By way of explanation, and without implying any limitation, stannates have a perovskite crystalline structure and strongly seed the perovskite material (e.g., MAPbI3, FAPbI3) growth conversion process. Stannates generally also meet other IFL requirements, such as ferroelectric behavior, sufficient charge carrier mobility, optical transparency, matched energy levels, and high dielectric constant.
In other embodiments, the IFL may comprise a plumbate. A plumbate according to some embodiments may be of the general formula M′PbO3, where M′ comprises any 2+ cation. In some embodiments, M′ may comprise a cationic form of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In some embodiments, the IFL may comprise a single species of plumbate, which in other embodiments, the IFL may comprise two or more different species of plumbate. In one embodiment, the plumbate has the formula SrPbO3. In another embodiment, the plumbate may have the formula BaPbO3. In yet another embodiment, the plumbate may have the formula CaPbO3. In yet another embodiment, the plumbate may have the formula PbIIPbIVO3.
By way of explanation, and without implying any limitation, plumbates have a perovskite crystalline structure and strongly seed the perovskite material (e.g., MAPbI3, FAPbI3) growth conversion process. Plumbates generally also meet other IFL requirements, such as ferroelectric behavior, sufficient charge carrier mobility, optical transparency, matched energy levels, and high dielectric constant.
Further, in other embodiments, an IFL may comprise a combination of a zirconate and a titanate in the general formula M′[ZrxTi1-x]O3, where x is greater than 0 but less than one 1, and M′ comprises any 2+ cation. In some embodiments, M′ may comprise a cationic form of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In some embodiments, the IFL may comprise a single species of zirconate, which in other embodiments, the IFL may comprise two or more different species of zirconate. In one embodiment, the zirconate/titanate combination has the formula Pb[ZrxTi1-x]O3. In another embodiment, the zirconate/titanate combination has the formula Pb[Zr0.52Ti0.48]O3.
By way of explanation, and without implying any limitation, a zirconate/titanate combination have a perovskite crystalline structure and strongly seed the perovskite material (e.g., MAPbI3, FAPbI3) growth conversion process. Zirconate/titanate combinations generally also meet other IFL requirements, such as ferroelectric behavior, sufficient charge carrier mobility, optical transparency, matched energy levels, and high dielectric constant.
In other embodiments, the IFL may comprise a niobate. A niobate according to some embodiments may be of the general formula M′NbO3, where: M′ comprises any 1+ cation. In some embodiments, M′ may comprise a cationic form of Li, Na, K, Rb, Cs, Cu, Ag, Au, Tl, ammonium, or H. In some embodiments, the IFL may comprise a single species of niobate, which in other embodiments, the IFL may comprise two or more different species of niobate. In one embodiment, the niobate has the formula LiNbO3. In another embodiment, the niobate may have the formula NaNbO3. In yet another embodiment, the niobate may have the formula AgNbO3.
By way of explanation, and without implying any limitation, niobates generally meet IFL requirements, such as piezoelectric behavior, non-linear optical polarizability, photoelasticity, ferroelectric behavior, Pockels effect, sufficient charge carrier mobility, optical transparency, matched energy levels, and high dielectric constant.
Any interfacial material discussed herein may further comprise doped compositions. To modify the characteristics (e.g., electrical, optical, mechanical) of an interfacial material, a stoichiometric or non-stoichiometric material may be doped with one or more elements (e.g., Na, Y, Mg, N, P) in amounts ranging from as little as 1 ppb to 50 mol %. Some examples of interfacial materials include: NiO, TiO2, SrTiO3, Al2O3, ZrO2, WO3, V2O5, MO3, ZnO, graphene, and carbon black. Examples of possible dopants for these interfacial materials include: Li, Na, Be, Mg, Ca, Sr, Ba, Sc, Y, Nb, Ti, Fe, Co, Ni, Cu, Ga, Sn, In, B, N, P, C, S, As, a halide, a pseudohalide (e.g., cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide, and tricyanomethanide), and Al in any of its oxidation states. References herein to doped interfacial materials are not intended to limit the ratios of component elements in interfacial material compounds.
In some embodiments, multiple IFLs made from different materials may be arranged adjacent to each other to form a composite IFL. This configuration may involve two different IFLs, three different IFLs, or an even greater number of different IFLs. The resulting multi-layer IFL or composite IFL may be used in lieu of a single-material IFL. For example, a composite IFL may be used any IFL shown in the example of
Generally, the composite IFL may be made using any of the materials discussed herein as suitable for an IFL. In one embodiment, the IFL comprises a layer of Al2O3 and a layer of ZnO or M:ZnO (doped ZnO, e.g., Be:ZnO, Mg:ZnO, Ca:ZnO, Sr:ZnO, Ba:ZnO, Sc:ZnO, Y:ZnO, Nb:ZnO). In an embodiment, the IFL comprises a layer of ZrO2 and a layer of ZnO or M:ZnO. In certain embodiments, the IFL comprises multiple layers. In some embodiments, a multi-layer IFL generally has a conductor layer, a dielectric layer, and a semi-conductor layer. In particular embodiments the layers may repeat, for example, a conductor layer, a dielectric layer, a semi-conductor layer, a dielectric layer, and a semi-conductor layer. Examples of multi-layer IFLs include an IFL having an ITO layer, an Al2O3 layer, a ZnO layer, and a second Al2O3 layer; an IFL having an ITO layer, an Al2O3 layer, a ZnO layer, a second Al2O3 layer, and a second ZnO layer; an IFL having an ITO layer, an Al2O3 layer, a ZnO layer, a second Al2O3 layer, a second ZnO layer, and a third Al2O3 layer; and IFLs having as many layers as necessary to achieve the desired performance characteristics. As discussed previously, references to certain stoichiometric ratios are not intended to limit the ratios of component elements in IFL layers according to various embodiments.
Arranging two or more adjacent IFLs as a composite IFL may outperform a single IFL in perovskite material PV cells where attributes from each IFL material may be leveraged in a single IFL. For example, in the architecture having an ITO layer, an Al2O3 layer, and a ZnO layer, where ITO is a conducting electrode, Al2O3 is a dielectric material and ZnO is a n-type semiconductor, ZnO acts as an electron acceptor with well performing electron transport properties (e.g., mobility). Additionally, Al2O3 is a physically robust material that adheres well to ITO, homogenizes the surface by capping surface defects (e.g., charge traps), and improves device diode characteristics through suppression of reverse saturation current.
As discussed above, each illustrated IFLs may include multiple layers. For example, in a 2-terminal tandem solar cell device as illustrated in
In certain embodiments, an IFL may comprise an internal electrode that is connected to an external load. In other embodiments, particularly in a 3-terminal design, an IFL may comprise an internal electrode embedded in IFL 2030 that is connected to an external load. In other embodiments, an IFL must be transparent to light having a wavelength greater than 500 nanometers.
Perovskite Material
As described above, a perovskite material may be incorporated into various of one or more aspects of a PV or other device. A perovskite material according to some embodiments may be of the general formula CwMyXz, where C comprises one or more cations (e.g., an amine, ammonium, phosphonium, a Group 1 metal, a Group 2 metal, and/or other cations or cation-like compounds); M is one or more metals (examples including Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr); X is one or more anions selected from the group consisting of oxides, halides, pseudohalides, chalcogenides (tellurides, sulfides, and selenides), and combinations thereof; and w, y, and z represent real numbers between 1 and 20. In some embodiments, C may include one or more organic cations. In some embodiments, each organic cation C may be larger than each metal M, and each anion X may be capable of bonding with both a cation C and a metal M. In particular embodiments, a perovskite material may be of the formula CMX3.
The inclusion of bulky organic cations, near or at the surface of a perovskite material may result in the formula of the perovskite material deviating from the “ideal” stoichiometry of perovskite materials disclosed herein. For example, inclusion of such organic cations may cause the perovskite material to have a formula that is either substoichiometric or superstoichiometric with respect to the CMX3 formula described herein. In this case, the general formula for the perovskite material may be expressed as CwMyXz, where w, y and z are real numbers. In some embodiments, a perovskite material may have the formula C′2Cn−1MnX3n−1, where n is an integer. For example, when n=1 the perovskite material may have the formula C′2MX4, when n=2 the perovskite material may have the formula C′2CM2X7, when n=3 the perovskite material may have the formula C′2C2M3X10, when n=4 the perovskite material may have the formula C′2C3M4X13, and so on. As illustrated by
In certain embodiments, C′ is benzylammonium and C is cesium, methylammonium or formamidinium. In other embodiments, C′ is phenylethylammonium and C is cesium, methylammonium or formamidinium. In certain embodiments, C′ is n-butylammonium and C is cesium, methylammonium or formamidinium. In other embodiments, C′ is iminomethanediammonium and C is cesium, methylammonium or formamidinium. In certain embodiments, C′ is a cation of 4-(aminomethyl)piperidine and C is cesium, methylammonium or formamidinium.
Examples of other “bulky organic” organic cations that may function as C′, include, but are not limited to, ethylammonium, propylammonium, n-butylammonium; perylene n-butylamine-imide; butane-1,4-diammonium; 1-pentylammonium; 1-hexylammonium; poly(vinylammonium); phenylethylammonium; 3-phenyl-1-propylammonium; 4-phenyl-1-butylammonium; 1,3-dimethylbutylammonium; 3,3-dimethylbutylammonium; 1-heptylammonium; 1-octylammonium; 1-nonylammonium; 1-decylammonium; and 1-icosanyl ammonium. Additionally, bulky organic cations with a tail that contains one or more heteroatoms in addition to the cationic species, the heteroatom may coordinate with, bind to, or integrate with the perovskite material crystal lattice. A heteroatom may be any atom in the tail that is not hydrogen or carbon, including boron, nitrogen, sulfur, oxygen, or phosphorous.
Other examples of bulky organic cations may include the following molecules functionalized with an ammonium group, phosphonium group, or other cationic group that may integrate into a surface C-site of a perovskite material: benzene, pyridine, naphthalene, anthracene, xanthene, phenathrene, tetracene chrysene, tetraphene, benzo[c]phenathrene, triphenylene, pyrene, perylene, corannulene, coronene, substituted dicarboxylic imides, aniline, N-(2-aminoethyl)-2-isoindole-1,3-dione, 2-(1-aminoethyl)naphthalene, 2-triphenylene-O-ethyl amine ether, benzylamine, benzylammonium salts, N-n-butyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 1-(4-alkylphenyl)methanamine, 1-(4-alkyl-2-phenyl)ethanamine, 1-(4-alkylphenyl)methanamine, 1-(3-alkyl-5-alkylphenyl)methanamine, 1-(3-alkyl-5-alkyl-2-phenyl)ethanamine, 1-(4-alkyl-2-phenyl)ethanamine, 2-Ethylamine-7-alkyl-Naphthalene, 2-Ethylamine-6-alkyl-Naphthalene, 1-Ethylamine-7-alkyl-Naphthalene, 1-Ethylamine-6-alkyl-Naphthalene, 2-Methylamine-7-alkyl-Naphthalene, 2-Methylamine-6-alkyl-Naphthalene, 1-Methylamine-7-alkyl-Naphthalene, 1-Methylamine-6-alkyl-Naphthalene, N-n-aminoalkyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 1-(3-Butyl-5-methoxybutylphenyl)methanamine, 1-(4-Pentylphenyl)methanamine, 1-[4-(2-Methylpentyl)-2-phenyl]ethanamine, 1-(3-Butyl-5-pentyl-2-phenyl)ethanamine, 2-(5-[4-Methylpentyl]-2-naphthyl)ethanamine, N-7-tridecyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), N-n-heptyl-N′-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 2-(6-[3-Methoxyl propyl]-2-naphthyl)ethanamine.
Two-dimensional lead iodide perovskite materials described in some embodiments of this disclosure only substantially contain one type of anioniodide. Thus, the 2D lead iodide perovskite materials of some embodiments of the present disclosure will not undergo halide phase segregation upon sunlight irradiation, unlike the mixture of iodide and bromide currently used in the state-of-the-art Si/perovskite and perovskite/perovskite tandem solar cells.
2D Perovskite Tandem Photovoltaic Device Design
2D perovskite materials disclosed herein may function well as a photoactive layer in tandem photovoltaic devices having a silicon photoactive layer. For example, with reference to
The perovskite materials illustrated in Tables 1 and 2 have properties, such as desirable band gaps, that allow them to function optimally in tandem photovoltaic cells with a silicon layer. Additionally, 2-D perovskites may be implemented in photovoltaic devices having three or more photoactive layers. For example, with respect to
Additionally, the 2D perovskites identified in Tables 1 and 2, and elsewhere herein, may perform well in tandem devices having a non-silicon bottom PV cell. For example, silicon PV cell 1550 may alternatively be a perovskite, CdTe, CIGS, GaAs, InP, or Ge cell. In some embodiments PV cell 1550 may alternatively include any one or more of perovskite (for example, FAPbI3, FASnI3, MASnI3, or CsSnI3), silicon (for example, polycrystalline silicon, single-crystalline silicon, or amorphous silicon), cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, copper indium selenide, copper zinc tin sulfide, gallium arsenide, germanium, germanium indium phosphide, indium phosphide, lead sulfide, one or more semiconducting polymers (e.g., polythiophenes (e.g., poly(3-hexylthiophene) and derivatives thereof, or P3HT); carbazole-based copolymers such as polyheptadecanylcarbazole dithienylbenzothiadiazole and derivatives thereof (e.g., PCDTBT); other copolymers such as polycyclopentadithiophene-benzothiadiazole and derivatives thereof (e.g., PCPDTBT), polybenzodithiophenyl-thienothiophenediyl and derivatives thereof (e.g., PTB6, PTB7, PTB7-th, PCE-10); poly(triaryl amine) compounds and derivatives thereof (e.g., PTAA); polyphenylene vinylenes and derivatives thereof (e.g., MDMO-PPV, MEH-PPV), and combinations thereof.
In some embodiments, the present disclosure may provide composite design of PV and other similar devices (e.g., batteries, hybrid PV batteries, FETs, LEDs, nonlinear optics (NLOs), waveguides, etc.) including one or more perovskite materials. In more general terms, some embodiments of the present disclosure provide PV or other devices having an active layer comprising one or more perovskite materials. In such embodiments, perovskite material (that is, material including any one or more perovskite materials(s)) may be employed in active layers of various architectures. In some embodiments, the same perovskite materials may serve multiple such functions, although in other embodiments, a plurality of perovskite materials may be included in a device, each perovskite material serving one or more such functions. In certain embodiments, whatever role a perovskite material may serve, it may be prepared and/or present in a device in various states. For example, it may be substantially solid in some embodiments. A solution or suspension may be coated or otherwise deposited within a device (e.g., on another component of the device such as a mesoporous, interfacial, charge transport, photoactive, or other layer, and/or on an electrode). Perovskite materials in some embodiments may be formed in situ on a surface of another component of a device (e.g., by vapor deposition as a thin-film solid). Any other suitable means of forming a layer comprising perovskite material may be employed.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood as referring to the power set (the set of all subsets) of the respective range of values, and set forth every range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.