Patent Application
20240336798
All patents, patent applications and publications cited herein are hereby incorporated by reference in their entirety. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.
This patent disclosure contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves any and all copyright rights.
The present invention relates to perovskite additives, compositions, methods of use, and materials thereof.
Perovskite materials hold the potential for making high-efficiency, low-cost solar devices through solution processing of Earth abundant materials. Research utilizes spin coating as a means of reliable application, but this method lacks the scalability demanded in industry.
Aspects of the invention are drawn towards a method of producing a quench-free perovskite material in ambient conditions, the method comprising: mixing a perovskite precursor with an organic solvent, thereby producing a perovskite precursor solution; incorporating a polymer additive into the perovskite precursor solution, thereby producing a perovskite-polymer ink; depositing the perovskite-polymer ink on a substrate; and flame annealing the perovskite-polymer ink on the substrate, thereby producing a quench-free perovskite material in ambient conditions. In embodiments, the perovskite precursor comprises CH3NH3PbI3. In embodiments, the polymer additive comprises gellan gum. In embodiments, the polymer additive comprises a polymer of the following structure:
In embodiments, the polymer additive is present in about 0.01 wt. % to about 2.29 wt. % of the perovskite precursors. In embodiments, the polymer additive is present in about 0.18 wt. % to about 0.56 wt. % of the perovskite precursors. In embodiments, depositing comprises blade coating, bar coating, slot die coating, spray coating, inkjet printing, and gravure printing. In embodiments, the flame annealing comprises an exposure to flame discharge at speeds comprising about 0.1 m/min to about 1000 m/min. In embodiments, flame annealing comprises flame exposure at a distance of about 0.1 cm to about 10 cm. In embodiments, the method does not require a quenching step. In embodiments, the perovskite material has improved fracture energy compared to a solution-processed material. For example, the fracture energy is greater than about 6.0 J/m2. For example, the fracture energy is about 6.6+/−2.5 J/m2 to about 10.9+/−2.3 J/m2.
In embodiments, the method further comprises tuning the morphology of the perovskite material by adjusting the concentration of the polymer additive to reduce the amount of nucleation. In embodiments, the morphology comprises domains greater than about 1 mm. In embodiments, the perovskite material has a root mean square roughness of about 1 nm to about 50 nm. In embodiments, the perovskite material has a carrier lifetime of greater than about 1 μs. In embodiments, the perovskite has increased resistance against heat and humidity.
Aspects of the invention are drawn towards a perovskite material produced by the methods described here. For example, the material is a perovskite solar cell. Other objects and advantages of this invention will become readily apparent from the ensuing description.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of necessary fee.
Aspects described herein provide perovskite additives, compositions, methods of use, and materials thereof.
Detailed descriptions of one or more embodiments are provided herein. It is to be understood, however, that the present invention can be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate manner.
The singular forms “a”, “an” and “the” include plural reference unless the context clearly dictates otherwise. The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification can mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”
Wherever any of the phrases “for example,” “such as,” “including” and the like are used herein, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise. Similarly, “an example,” “exemplary” and the like are understood to be nonlimiting.
The term “substantially” allows for deviations from the descriptor that do not negatively impact the intended purpose. Descriptive terms are understood to be modified by the term “substantially” even if the word “substantially” is not explicitly recited.
The terms “comprising” and “including” and “having” and “involving” (and similarly “comprises”, “includes,” “has,” and “involves”) and the like are used interchangeably and have the same meaning. Specifically, each of the terms is defined consistent with the common United States patent law definition of “comprising” and is therefore interpreted to be an open term meaning “at least the following,” and is also interpreted not to exclude additional features, limitations, aspects, etc. Thus, for example, “a process involving steps a, b, and c” means that the process includes at least steps a, b and c. Wherever the terms “a” or “an” are used, “one or more” is understood, unless such interpretation is nonsensical in context.
As used herein, the term “about” can refer to approximately, roughly, around, or in the region of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20 percent up or down (higher or lower).
As used herein, the term “substantially the same” or “substantially” can refer to variability typical for a particular method is taken into account.
The terms “sufficient” and “effective”, as used interchangeably herein, can refer to an amount (e.g., mass, volume, dosage, concentration, and/or time period) needed to achieve one or more desired result(s).
Before explaining at least one embodiment of the disclosure in detail, it is to be understood that the disclosure is not necessarily limited in its application to the details set forth in the following description or exemplified by the examples. The disclosure is capable of other embodiments or of being practiced or carried out in various ways. Other compositions, compounds, methods, features, and advantages of the present disclosure will be or become apparent to one having ordinary skill in the art upon examination of the following drawings, detailed description, and examples. All such additional compositions, compounds, methods, features, and advantages can be included within this description, and be within the scope of the present disclosure.
Aspects of the invention are drawn towards a method of producing a quench-free perovskite material in ambient conditions, the method comprising: mixing a perovskite precursor with an organic solvent, thereby producing a perovskite precursor solution; incorporating a polymer additive into the perovskite precursor solution, thereby producing a perovskite-polymer ink; depositing the perovskite-polymer ink on a substrate; and processing the perovskite-polymer ink on the substrate, thereby producing a quench-free perovskite material in ambient conditions.
In embodiments, the perovskite-polymer ink composition can vary to tune the chemistry of the perovskite. As used herein, the term “ink” can refer to any fluid, regardless of color, that can be applied to a substrate for manufacturing applications. For example, “ink” can refer to the combination of polymer precursors and solvent.
As used herein, the term “perovskite” can refer to a material or a layer with a three-dimensional crystal structure related to that of CaTIO3 or CaTiC. The skilled person will appreciate that a perovskite material can be represented by the formula ‘A’‘B’‘X’3, wherein ‘A’ is at least one cation, ‘B’ is at least one cation, and ‘X’ is at least one anion. The cation ‘A’ can be organic, inorganic, or an organic-inorganic cation. When the cation ‘A’ is organic, the organic cation can have the formula (R1R2R3R4N)n+ or (R5R6N═CH—NR7R8)n+, where R is hydrogen, unsubstituted or substituted alkyl, or unsubstituted or substituted aryl, and n is equal or superior to one (e.g. ‘CH3NH3’+ refers as MA, ‘HC(NH2)2’+ refers as FA, ‘C(NH2)3’+ refers as GA). When the cation ‘A’ is inorganic, the cation can be selected from the group consisting of Ag+, Li+, Na+, K+, Rb+, Cs+, Be2+, Mg2+, Ca2+, Pb2+, Sr2+, Ba2+, Fe2+, Sc3+, Y3+, and La3+. The cation can be used as a single or multiple ion (e.g. (Mg,Fe)SiO3), YBaCuO3).
When the cation ‘A’ is organic-inorganic, the cation can be used as a single or multiple ion such as ‘A’=(M1n(R21−xR3x) (100−n)), where R is preferably an organic cation as described above and M is preferably an inorganic cation comprised as described above (e.g. FA1−xGax‘B’‘X’3, Csx(MAnFA1−n) (100−x) ‘B’‘X’3).
The cation ‘B’ can be a metal cation selected from the group consisting of Pb2+, Sn2+, Gc2+, Bi2+, Cu2+, Au2+, Ag2+, Sb2+, Nb2+, Ti2+, Mg2+, Si2+, Ca2+, Sr2+, Cd2+, Ni2+, Mn2+, Fe2+, Zr4+, Co2+, Pd2+, Yb2+, Eu2+, Ce4+, and Tb4+. The divalent metal bearing compound can be derived from various salts including but not limited to lead acetate and lead nitrate for instance. The anion ‘X’ can be selected from the group consisting of halide anions comprising Cl—, Br−, I−, F−, or chalcogenide anions comprising O2−, S2−, Se2−, Te2−, or polyanions comprising BF4−, PF6−, SCN—. The anion can be used as a single or multiple ions such as ‘X’=(R1−xRx), where R is an anion as listed above. Other type of perovskite that can be elaborated: Cuprate perovskite (La2−xBaxCuO4, YBa2Cu3O7, Ba2MCu3O7, where M is a rare earth ion such as Pr, Y, Nd, Sm, Gd, Dy, Ho). Metal perovskite can be produced based on a RT3M structure, where R is a rare-earth ion, T is a transition metal ion (Pd, Rh, Ru) and M is a light metalloid (e.g. B, C).
In embodiments, perovskite precursor solutions can comprise those known in the art, for example: CH3NH3PbX3, CSx(CH3(NH2)2)1−xPbX3, CSx(CH3NH3)x(CH3(NH2)2)1−x) (100−x)PbX3, AxCsy((CH3NH3)/(CH3(NH2)2)1−z)1−yPbX3 where A is an alkali metal (Li, Na, K, Rb), suitable for the preparation of photoactive layer; BaTiO3, PbTiO3, CaTIO3, SrTiO3, PbZrO3, SrTiO3, KTaO3, KNbO3, NaNbO3, Pb(Mg1/3Nb2/3)O3, Pb(Zn1/3Nb2/3)3, Pb(Mn13Sb2/3)O3, Pb(Co1/3Nb2/3)O3, Pb(Mn1/3Nb2/3)O3, Pb(Ni13Nb2/3)O3, Pb(Sb1/2Sn1/2)O3, Pb(Co12W1/2)O3, Pb(Mg1/2W1/2)O3, LiNbO3, LiTaO3, BiTiO3, NaTIO3, NaNbO3, KNbO3, for the growth of ferroelectric and piezoelectric material; La1−xSrxMnO3, La2NiO4, La2CoO4, GdBaCo2O5, PrBaCo2O5, NdBa1−xSrxCoO2O5, Ba1−xSrxCo1−yFeyO3, for the elaboration of fuel cells; BiCr1−xGaxO3, for magnetic materials; NaNbO3, KNbO3, LaFcO3, LaCoxFc1−xO3, La1−xSrxCoO3, LaSrNiO4, LaxSrx−1FeyBiy−1O3, La2NiO4, La2−xSrxCuO4, LaSrNi1−xAlxO4, LaMnO3, LaFcO3, LaCoO3, LaTi1−xCuxO3, LiTaO3, NaTaO3, KTaO3, CaTa2OL6, SrTa2O6, BaTa2O6, for catalysis; La-based perovskite-type oxides (La1−xSrxCoO3, Pr1−xSrxCoO3, Sm1−xSrxCoO3, Gd1−xSrxCoO3, Tb1−xSrxCoO3, LaCoO3, La1−xSrxMnO3, LaCo1−xNixO3), for electronic conductions.
In embodiments, the perovskite can comprise divalent cations such as propylene diammonium (e.g., Dion-Jacobson perovskite) in addition to the monovalent cations (e.g., Ruddledsen-Popper) (scc, e.g., R. Liu, X. Hu, M. Xu, H. Ren, H. Yu, ChemSusChem 2023, 16, e202300736). In embodiments, the disclosure can comprise cations selected from the group consisting of formamidinium, cesium, rubidium, sodium, potassium, dimethylammonium, butylammonium, propylene diammonium, benzylammonium, and phenethylammonium. The skilled person will be able to choose the perovskite forming material as required by a specific application. For example, the perovskite precursor solution comprises CH3NH3PbI3.
The solution can comprise at least one organic solvent. The solvent can be chosen from non-polar solvents, polar aprotic solvents, or polar protic solvents. In embodiments the solvent is dimethyl sulfoxide (DMSO). In some embodiments, the solvent can be comprise: Acetic acid, Acetone, Acetonitrile, n-Butanol, n-Butyrolactone, n-Pentanol, n-Propanol, n-Octanol, 2-Methyl-2-Propanol, Butylacetate, Chlorobenzene, Chloroform, Cyclohexane, Dichloromethane, Diethylether, 1,2-Dichloroethylene, Diisopropylether, Dimethylacetamide, Dimethylethanolamine, Dioxane, N,N-Dimethylformamide, Dimethyl sulfoxide, Ethanol, Ethylacetate, Ethylene glycol, Ethylmethylketone, Heptane, 15 Hexamethylphosphoramide, Hexane, Isopropylalcohol, 3-Methyl-1-Butanol, Methanol, Methylamine, Methylenechloride, N-methylpyrrolidone, Pentane, n-Propylalcohol, Propylene carbonate, Pentachloroethane, 1,1,2,2-Tetrachloroethane, 1,1,1-Trichloroethane, Tetrachloroethylene, Tetrachloromethane, Tetrahydrofurane, tert-Butanol, Toluene, Trichloroethylene, Water, Xylene, and mixtures thereof.
The mixture can comprise an additive (used to control the crystallization during the perovskite synthesis). In embodiments, the polymer additive is thickening agent. For example, the polymer additive is gellan gum. In embodiments the polymer additive comprises a polymer of the following structure:
As used herein, the term “gellan gum” can refer to a linear, anionic, extracellular exopolysaccharide secreted by the bacterium Pseudomonas elodea, that consists of repeating tetrassaccharide units composed by two D-glucose, one D-glucuronic acid and one L-rhamnose residue. In embodiments, the gellan gum can comprise gellan gum acetylated (high-acyl) and de-acetylated (low-acyl). High-acyl gellan gum contains two acyl substituents, namely acetate (one acetate group for every two repeat units) and glycerate (one glycerate group for every repeat unit) both located on the same glucose residue, while low-acyl gellan gum is produced by basic hydrolysis and typically contains less than about 5% acyl substituents to no acyl groups. For example, the gellan gum described herein can comprise CAS No. J63423-30.
In embodiments, the polymer additive is present in less than about 2.5 wt. % of the polymer precursor. In embodiments, the polymer additive is present in less than about 1 weight percent (wt. %) of the perovskite precursor. In embodiments, the polymer additive is present in less than about 0.01 wt. %, about 0.01 wt. %, about 0.02 wt. %, about 0.03 wt. %, about 0.04 wt. %, about 0.05 wt. %, about 0.06 wt. %, about 0.07 wt. %, about 0.08 wt. %, about 0.09 wt. %, about 0.1 wt. %, about 0.15 wt. %, about 0.18 wt. %, about 0.2 wt. %, about 0.25 wt. %, about 0.3 wt. %, about 0.35 wt. %, about 0.4 wt. %, about 0.45 wt. %, about 0.5 wt. %, about 0.55 wt. %, about 0.60 wt. %, about 0.65 wt. %, about 0.70 wt. %, about 0.75 wt. %, about 0.80 wt. %, about 0.85 wt. %, about 0.90 wt. %, about 0.95 wt. %, about 0.99 wt. %, about 1.0 wt. %, about 1.25 wt. %, about 1.50 wt. %, about 1.75 wt. %, about 2.0 wt. %, about 2.1 wt. %, about 2.2 wt. %, about 2.3 wt. %, about 2.4 wt. %, about 2.5 wt. %, or greater than 2.5 wt. %. For example, the polymer additive is present in about 0.01 wt. % to about 2.29 wt. % of the polymer precursor. For example, the polymer additive is present in less than about 1.0 wt. % of the polymer precursor. For example, the polymer additive is present in about 0.18 wt. % or about 0.56% weight percent of the perovskite precursors. For example, the polymer additive is present in about 0.56 wt. %.
In embodiments, the depositing comprises blade coating. In embodiments, the blade coater gap comprises less than about 5 μm, about 7.5 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 50 μm, about 75 μm, about 100 μm, about 125 μm, about 150 μm, about 175 μm, about 200 μm, about 225 μm, about 250 μm, about 275 μm, about 300 μm, about 325 μm, about 350 μm, about 375 μm, about 400 μm, or greater than about 400 μm.
In embodiments, the blade speed comprises about 2.5 mm/s to about 30 mm/s. For example, the blade speed comprises about 0.25 mm/s, about 0.50 mm/s, about 0.75 mm/s, about 1.0 mm/s, about 1.25 mm/s, about 1.50 mm/s, about 1.75 mm/s, about 2.0 mm/s, about 2.5 mm/s, about 5 mm/s, about 7.5 mm/s about 10 mm/s, about 15 mm/s, about 20 mm/s, about 25 mm/s, about 30 mm/s, about 35 mm/s, about 40 mm/s, about 45 mm/s, about 50 mm/s, about 55 mm/s, about 60 mm/s, about 70 mm/s, about 80 mm/s, about 90 mm/s, about 100 mm/s, or greater than about 100 mm/s.
In embodiments, the processing comprises exposure to flame discharge or atmospheric plasma, or thermal annealing. As used herein, the terms “flame discharge” and “flame annealing” can be used interchangeably.
In embodiments, the polymer additive provides resistance against the discharges/energies of the flame, plasma, and/or thermal annealing.
In embodiments, the flame annealing comprises depositing the ink with a printing method described herein or known in the art, passing a flame discharge over the ink after a delay of about 0.1 seconds to about 100 seconds at the speeds and distances described herein. The exact conditions can depend on the material chemistry/composition/solvents used, and would be adjusted accordingly by one of ordinary skill in the art. This process can be amenable to in-line processing. Without wishing to be bound by theory, in a manufacturing method, the flame can remain stationary while the substrate passes under the flame at speeds and distances described herein.
In embodiments, the flame source for the flame annealing can be any source known in the art. For example, the flame source can comprise a butane flame source, a propane flame source, or natural-gas flame source. In embodiments, the flame can pass over the sample at speeds of about 0.1 m/min to 1000 m/min with a distance ranging from about 0.1 cm to about 10 cm.
In embodiments, the flame can pass over the sample with speeds comprising about 0.1 m/min to about 1000 m/min. For example, the exposure comprises less than about 0.01 m/min, about 0.01 m/min, about 0.025 m/min, about 0.05 m/min, about 0.075 m/min, about 0.1 m/min, about 0.25 m/min, about 0.5 m/min, about 0.75 m/min, about 1 m/min, about 2.5 m/min, about 5 m/min, about 7.5 m/min, about 10 m/min, about 12.5 m/min, about 15 m/min, about 20 m/min, about 25 m/min, about 30 m/min, about 40 m/min, about 50 m/min, about 60 m/min, about 70 m/min, about 80 m/min, about 90 m/min, about 100 m/min, about 125 m/min, about 150 m/min, about 175 m/min, about 200 m/min, about 225 m/min, about 250 m/min, about 275 m/min, about 300 m/min, about 325 m/min, about 350 m/min, about 375 m/min, about 400 m/min, about 450 m/min, about 500 m/min, about 550 m/min, about 600 m/min, about 650 m/min, about 700 m/min, about 750 m/min, about 800 m/min, about 850 min/min, about 900 m/min, about 950 m/min, about 1000 m/min, about 1100 m/min, about 1200 m/min, about 1300 m/min, about 1400 m/min, about 1500 m/min, about 1750 m/min, about 2000 m/min, or greater than 2000 m/min.
In embodiments, the sample can be exposed to the flame at a distance of about 0.1 cm to about 10 cm. For example, the distance can comprise less than about 0.01 cm, about 0.01 cm, about 0.025 cm, about 0.05 cm, about 0.075 cm, about 0.1 cm, about 0.25 cm, about 0.5 cm, about 0.75 cm, about 1.0 cm, about 1.25 cm, about 1.5 cm, about 1.75 cm, about 2.0 cm, about 2.25 cm, about 2.5 cm, about 2.75 cm, about 3.0 cm, about 3.25 cm, about 3.5 cm, about 3.75 cm, about 4.0 cm, about 4.25 cm, about 4.5 cm, about 4.75 cm, about 5.0 cm, about 5.25 cm, about 5.5 cm, about 5.75 cm, about 6.0 cm, about 6.25 cm, about 6.5 cm, about 6.75 cm, about 7.0 cm, about 7.25 cm, about 7.5 cm, about 7.75 cm, about 8.0 cm, about 8.25 cm, about 8.5 cm, about 8.75 cm, about 9.0 cm, about 9.25 cm, about 9.5 cm, about 9.75 cm, about 10.0 cm, about 10.25 cm, about 10.5 cm, about 10.75 cm, about 11.0 cm, about 11.25 cm, about 11.5 cm, about 11.75 cm, about 12.0 cm, about 13.0 cm, about 14.0 cm, about 15.0 cm, or greater than about 15.0 cm.
In embodiments, the thermal annealing comprises exposure to about 100° C. for about 25 minutes. In embodiments, the method does not require a quenching step. In embodiments, the thermal annealing comprise exposure to about 100 C to about 350 C and from about 5 to about 120 minutes.
In embodiments, the perovskite material has improved fracture energy compared to a solution-processed material. For example, the fracture energy can be greater than about 6.0 J/m2. For example, the fracture energy can be about 6.6+/−2.5 J/m2 to about 10.9+/−2.3 J/m2.
Because the final morphology of the PVSK is dependent on the balance of the nucleation and growth regimes, controlling the rate of supersaturation during processing is an exciting feature described herein. For example, tuning the morphology of the perovskite material can comprise adjusting the concentration of the polymer additive to reduce the amount of nucleation. For example, depending on the amount of additive used, the LaMer curve can shift accordingly. Higher additive concentrations can reduce the amount of nucleation to the point where morphology with domains >1 mm. For example, methods described herein can be used to tune the morphology to produce small grains, large domains, and/or dendritic structures. For example, as used herein, small grains can comprise about 1 to about 1000 nm. For example, as used herein, large domains can comprise about 1 μm to about 1000 μm or greater. For example, methods described herein can improve the uniformity of the domains.
In embodiments, the domains of the perovskite materials described herein can comprise about 0.0001 mm to about 1.0 mm. For example, the domains can be less than 0.0001 mm, about 0.0001 mm, about 0.00025 mm, about 0.0005 mm, about 0.00075 mm, about 0.001 mm, about 0.0025 mm, about 0.005 mm, about 0.0075 mm, about 0.01 mm, about 0.025 mm, about 0.05 mm, about 0.075 mm, about 0.1 mm, about 0.25 mm, about 0.5 mm, about 0.75 mm, about 1.0 mm, about 1.25 mm, about 1.5 mm, about 1.75 mm, about 2.0 mm, or great than about 2.0 mm.
In embodiments, the perovskite material can have a root mean square roughness value of less than about 1.0 nm, about 1.0 nm, about 1.5 nm, about 2.0 nm, about 2.5 nm, about 3.0 nm, about 3.5 nm, about 4.0 nm, about 4.5 nm, about 5.0 nm, about 5.5 nm, about 5.6 nm, about 5.7 nm, about 5.8 nm, about 5.9 nm, about 6.0 nm, about 6.5 nm, about 7.0 nm, about 8.0 nm, about 8.5 nm, about 9.0 nm, about 9.5 nm, about 10.0 nm, about 10.5 nm, about 11.0 nm, about 11.5 nm, about 12.0 nm, about 12.5 nm, about 13.0 nm, about 13.5 nm, about 14.0 nm, about 14.5 nm, about 15 nm, about 15.5 nm, about 16.0 nm, about 16.5 nm, about 17.0 nm, about 17.5 nm, about 18.0 nm, about 18.5 nm, about 19.0 nm, about 19.5 nm, about 20 nm, about 20.5 nm, about 21.0 nm, about 22.0 nm, about 23.0 nm, about 24.0 nm, about 25.0 nm, about 27.5 nm, about 30.0 nm, about 32.5 nm, about 35.0 nm, about 37.5 nm, about 40.0 nm, about 42.5 nm, about 45.0 nm, about 47.5 nm, about 50 nm, or greater than 50 nm.
In embodiments, the perovskite material has improved optoelectronic properties. For example, the perovskite material can a carrier lifetime of greater than about 1 μs.
In embodiments, the perovskite has increased resistance against heat and humidity. For example, methods described herein can produce compositions which have improved retention of their photoreactive phase after moisture exposure.
Aspects of the disclosure are related to a perovskite material produced by the methods described herein. In embodiments, the perovskite material can be utilized within the photonic field. For example, the perovskite material can be used to form efficient photoactive layers in an inverted PEDOT:PSS solar cell device.
In embodiments, the semiconductor/optoelectronic/photonic device can comprise a photovoltaic device. In some embodiments, the semiconductor/optoelectronic/photonic device can be other than a photovoltaic device and can be for instance a light-emitting diode (LED), a ferroelectric device (BaTiO3), a superconductor device (YBaCuO3) (broadly speaking, any ionic conductivity device).
The term “semiconductor device”, as used herein, can refer to a device comprising a functional component which comprises a semiconductor material. This term can be understood to be synonymous with the term “semiconducting device”. Examples of semiconductor devices include a photovoltaic device, a solar cell, a photo detector, a photodiode, a photosensor, a chromogenic device, a transistor, a light-sensitive transistor, a phototransistor, a solid state triode, a battery, a battery electrode, a capacitor, a super-capacitor, a light-emitting device, a laser or a light-emitting diode.
The term “optoelectronic device”, as used herein, can refer to devices which source, control or detect light. Light is understood to include any electromagnetic radiation. Examples of optoelectronic devices include photovoltaic devices, photodiodes (including solar cells), phototransistors, photomultipliers, photoresistors, and light emitting diodes.
In an optoelectronic device such as a photovoltaic device, the perovskite layer is a part of the photoactive region which comprises: An n-type region comprising at least one n-type layer; a p-type region comprising at least one p-type layer; a layer of an intrinsic, undoped perovskite semiconductor, wherein this latter has a band gap between 0.5 and 3.0 eV. In embodiments, the bandgaps of PVSKs described herein are tunable.
As used herein, the term ‘n-type region’, refers to a region of one or more electron-transporting materials. Similarly, the term ‘n-type layer’ refers to a layer of an electron-transporting material. An electron-transporting material could be a single electron-transporting compound or elemental material, or a mixture of two or more electron-transporting compounds or elemental materials. An electron-transporting compound or elemental material can be undoped or doped with one or more dopant elements.
As used herein, the term ‘p-type region’ refers to a region of one or more ion or hole-transporting materials. This region comprises a p-type layer and occasionally a p-type exciton blocking layer. The term ‘p-type layer’ refers to a layer of an ion or hole-transporting material. An ion or hole-transporting material could be a single ion or hole-transporting compound or elemental material, or a mixture of two or more ion or hole-transporting compounds or elemental materials. An ion or hole-transporting compound or elemental material can be undoped or doped with one or more dopant elements.
Examples are provided below to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only, since alternative methods can be utilized to obtain similar results.
A gum-based polymer additive in a semiconducting halide perovskite ink for scalable open-air flame processing of in-line thin film photovoltaic manufacturing is described herein. The additive improves the printability and processability of the ink to be compatible with rapid high-temperature processing.
Aspects described herein are surprising improvements upon a “method for forming perovskite layers using atmospheric pressure plasma” (U.S. Pat. No. 10,636,632B2) where the deposition of perovskite ink is followed by an atmospheric pressure plasma that efficiently cures the precursor to provide the desired perovskite film. This work is in the field of renewable energy materials, manufacturing, and sustainability in an effort to expand on low-cost domestic solar technology.
Unmodified perovskite inks designed for conventional solution processing based on spin coating produce pinholed, uneven, and shunted films when processed in air or with scalable processing methods. Polymeric modifiers have been used to improve film uniformity and density. These additives not only act as rheological modifiers by increasing ink viscosity, thus allowing longer periods for crystallization and smooth films, but the long chains of the polymer create an organizational scaffold that increases resistance to humidity. Furthermore, additives from the food industry, such as corn starch, can enhance mechanical integrity and the operational lifetime of devices in addition to inducing spherulitic domains that can be tuned in size by temperature and precursor concentration to increase performance.
Aspects of our invention are directed towards incorporation of nontoxic starch and gum-based materials from the food industry, are studied as additives on improving perovskite quality and manufacturability using scalable, one-step processing in open air. The use of a nontoxic solvent system further extends the wetting period, thus improving crystallization control. The invention also incorporates a high-temperature flame discharge to rapidly crystallize the perovskite, and the use of the additive enables the ability to adapt these rapid process conditions.
This technology addresses several challenges that need to be overcome within the field of perovskite photovoltaics, particularly with regards to material processing and device reliability:
The two non-limiting, exemplary properties of the invention are the incorporation of the polymer additive in the perovskite ink in the first step of the process for depositing a high quality and uniform ink and the use of a flame discharge to provide a high energy source for extremely fast conversion of the ink to a high quality thin film.
We are able to control and tune the morphology of the perovskite film to achieve much larger grain sizes (˜mm scale) compared to conventional processing techniques (μm scale), an effect which improves both optoelectronic and mechanical properties. We measure the film stress to be tunable and compressive based on the additive concentration. We find that the additive enables reproducible and scalable perovskite devices to be produced in ambient conditions that match state-of-the-art performance on manufacturing scales. The devices are stable under both thermal cycling and continuous operation. Without wishing to be bound by theory, the compressive stress in the films along with significantly reduced ion migration based on impedance spectroscopy and transient photocurrent measurements as can be reasons for the improved device stability. These effects can be indicated through aging perovskites with different film stresses and additive concentrations for mechanistic understanding of how film stress influences ion migration and device stability.
Companies working in the development of the next generation solar cell panels can be interested by this technology. This can include those companies invested in single-junction and tandem markets. The lightweight and extremely low-cost process enables applications in UAVs, drones, satellites, agrivoltaics, trucking (providing energy for refrigeration), residential, commercial, and eventually utility-scale solar installations.
The technology is a gum-based polymer additive in a semiconducting halide perovskite ink for scalable open-air flame processing of in-line thin film photovoltaic manufacturing. Conventional unmodified perovskite inks designed for conventional solution processing based on spin coating produce pinholed, uneven, and shunted films when processed in air or with scalable processing methods. Polymeric modifiers have been used to improve film uniformity and density. These additives not only act as rheological modifiers by increasing ink viscosity, thus allowing longer periods for crystallization and smooth films, but the long chains of the polymer create an organizational scaffold that increases resistance to humidity. The present invention incorporates non-toxic starch and gum-based materials from the food industry. The additive improves the printability and processability of the ink to be compatible with rapid high-temperature processing. The use of a nontoxic solvent system further extends the wetting period, thus improving crystallization control. The invention also incorporates a high-temperature flame discharge to rapidly crystallize the perovskite, and the use of the additive enables the ability to adapt these rapid process conditions. The formed perovskite exhibits a 10× increase in fracture energy, an extremely tough grain structure, and tunable and compressive film stress compared to typical solution-processed materials.
Perovskite films using a food industry-based polymeric additive are described herein.
Described herein is the inclusion of a polymeric saccharide additive, gellan gum (GG), for controlling the crystallization of halide perovskite films. GG enables open-air blade coating of scalable perovskite films with improved morphology and optoelectronic properties in ambient without a quench step compared to films spin coated in a glovebox with antisolvent. We tune the amount of GG in the perovskites precursor and study the interplay between GG concentration and processability, morphological control, and increased stability under humidity, heat, and mechanical testing. The simplicity of implementing this approach and insensitivity to environmental conditions enables a wide process window for the production of low-defect, mechanically robust, and operationally stable perovskites with fracture energies among the highest obtained for perovskites.
The halide perovskite (PVSK) family of materials proves to be the rising star in the next generation of solar devices with lab reported power conversion efficiencies (PCE) rivaling commercial silicon modules at 26.1% after just over ten years of research [1]. Additionally, the compositionally tunable bandgap of PVSK films offers an attractive means of advancing silicon modules when used in tandem, making the push towards scalability increasingly urgent. While PVSK technologies show great promise, the U.S. Department of Energy continues to consider manufacturability, stability, and scalability as key challenges in the effort to reach commercialization [2].
In an effort to address these challenges and move from lab-to-fab, emphasis has shifted from processing via spin coating to innovating scalable techniques such as spray coating, electrochemical deposition, ink jet printing, slot die coating, and doctor-blade coating [3-5]. Meniscus driven doctor-blade coating offers a promising lab-scale deposition method that easily translates to industrial manufacturing techniques such as slot die coating and roll-to-roll manufacturing on flexible substrates. However, this transition from spin coating to meniscus driven processing is often complicated by an incompatibility with inks optimized for use with traditional antisolvent quenching. Tuning parameters associated with alternative quenching methods such as gas or vacuum-based techniques further complicates process optimization, reproducibility, and the overall feasibility of commercialization. Entire studies have been dedicated to reproducibility of these methods [6].
Furthermore, transitioning from lab style inert fabrication to industrial ambient manufacturing poses further complications. Open-air, antisolvent free blade coating of unmodified PVSK inks optimized for spin coating in an inert environment with an antisolvent produces void filled, uneven, and shunted films, demonstrating that the mild annealing step alone is not enough to control crystallization [3,7,8]. Solvent engineering and polymeric modifiers can be used to improve film uniformity, density, and stability while also improving manufacturability through an increase in ink viscosity which offers improved fluid dynamics and crystallization while blade coating [9-11]. Furthermore, biopolymers from the food industry, such as cornstarch, can enhance mechanical integrity and the operational lifetime of devices in addition to inducing spherulitic domains that can be tuned in size by temperature and precursor concentration to increase PCEs while a contemplated organizational scaffolding increases resistance to humidity [12-14].
The biopolymer chosen for this study, gellan gum—a non-toxic extracellular polysaccharide produced from bacteria known as Sphingomonas elodea—forms firm, transparent gels in the presence of metallic ions and features heat resistance properties [15,16]. Without wishing to be bound by theory, gellan gum can mediate the gelation process by undergoing a reversible transition from a disordered single chain to a self-assembled highly ordered double helix upon cooling through crosslinking structures, whereby various fibrous formations are possible depending on temperature, cation attachment, and concentration introduced [16]. Outside of being used as a suspension agent, binder, and coagulant in the food industry, gellan gum can be used field to create films without interrupting expected electrical properties [17,18]. For example, gellan gum has been incorporated into mixed halide perovskites in a polymer mediated crystallization process to achieve devices with equivalent PCEs and improved photostability compared to reference cells [19]. The addition of gellan gum has can also induce an intrinsic compressive stress within the perovskite film, a property correlated with improved mechanical and environmental stability [20,21].
Rather than directly controlling solvent evaporation with an antisolvent, air-gun, or the use of heat, gellan gum alters fluid dynamics and free energy considerations within the ink to tune the crystallization process by acting as a barrier to excessive homogenous and early heterogeneous nucleation through intermediate interactions and a change in wetting angle thanks to rheological modification. These factors stimulate radial, spherulitic growth of similarly oriented domains that grow in a space filling nature that combats the presence of pinholes while possibly collecting defects and impurities, including the additive, along grain boundaries which can assist in relieving detrimental thermal or intrinsic stresses associated with the thermal expansion mismatch between the PVSK layer and substrate without inhibiting optoelectronic properties [10, 20].
Described herein is a method of polymer mediated crystallization enabling high quality blade coated methylammonium lead iodide, CH3NH3PbI3 (MAPI), films in open air without quenching that feature improved mechanical, optoelectronic, and stability characteristics. With the introduction of less than one weight percent of gellan gum, we describe that the crystallization process can be fully controlled, which allows tuning of the perovskite film morphology according to additive concentration. This tunability can be enabled by controlling supersaturation rates of the evaporating wet film, which thereby changes the balance between the nucleation and growth regimes involved in the overall crystallization process [10, 20].
We tested several concentrations of MAPI-x % gellan gum (GG), where x % GG is the weight percent of gum to perovskite precursors. For example, 0.18% corresponds to 1.1 mg of GG in 1 mL of MAPI. Note that the ratio of perovskite precursor to dimethyl sulfoxide (DMSO) remained the same for all inks, 28 wt %. As seen in
After identifying the rheological properties of GG, we then studied the effect of viscosity on PVSK crystallization. While the exact mechanisms of the PVSK crystallization process remain an active area of research, the LaMer theory, a qualitative analogy which builds upon Classical Nucleation Theory to describe the removal of solvent from a simplified monodispersed crystalline nanoparticle system is, without wishing to be bound by theory, presented as a link between theory and processing [5,14,22-27]. The LaMer curve can be plotted with concentration versus time respective to the nucleation and growth regimes to describe their respective dominance and influence on morphology, yet this plot is not always intuitive from a processing point of view.
For example, the red curve in
GG enables modulation between these two extremes. The green curve in
We then performed optoelectronic characterization of the MAPI films as a function of GG concentration. Illuminated lock-in thermography (ILIT) was thus performed on blade coated samples with 0%, 0.18% and 0.56% GG to observe the correlation between morphology changes in the film and thermographic response with the compositions. Thermal topography images from
Next, we tested the effects of GG inclusion on the operational stability of MAPI films. X-ray diffraction spectrums and photoluminescent data were collected for unencapsulated MAPI blade coated samples after humidity (25 C, 85% RH) and heat aging (85 C in vacuum) initially and after three hours and 12 hours, as shown in
XRD and PL data were then collected for ambient MAPI blade coated samples after aging under vacuum at 85° C. initially and after three hours and 12 hours, as shown in
As seen in
In addition to the improved resistance to aging, without wishing to be bound by theory, the mechanical properties of the GG films can be improved as well. Our previous work validated this in spin coated PVSK with starch additives, where a significant increase in fracture energy was observed with the addition of 10 wt % of starch and above [13]. Double cantilever beam testing was performed on spin coated control and blade coated samples with varying compositions of GG to observe the changes in the fracture energy, Gc, of the MAPI films.
Our findings indicate that the addition of an optimized concentration of GG, 0.56%, balances the crystal nucleation and growth regimes. As a result, this quench-free polymer-mediated crystallization process of ambient blade coated MAPI thin films induces compact and continuous morphologies. Lock-in thermography and J-V curves indicate the improved optoelectronic properties of the 0.56% GG inclusion. Additionally, increased mechanical integrity is achieved with robust fracture energies indicating resistance to cracking and delamination, and superior optoelectronic and crystalline durability and stability after 12 hours of aging in 85% RH or 85° C.
With the help of the biopolymer additive and efficient meniscus driven blade coating, the crystallization process can be effectively altered. Supersaturation rates can be tuned to produce a unique range of morphologies with variable domain sizes and degrees of surface texturing according to additive concentration and without the use of excessive heat. The result is a reduction of detrimental tensile thermal stresses which can advance degradation in the film. By altering the rheology and free energy considerations of the PVSK ink, radial, spherulitic growth of similarly oriented domains grow in a space filling nature while concentrating defects, impurities, and possibly the additive to domain boundaries. This serves as one possible mechanism of self-passivation behind the improved resilience to heat and humidity aging. Notably, this work shows a systematic means of investigating key stability characteristics derived from a tunable morphology for the scalable, quench free production of mechanically and environmentally robust PVSK films. For the first time, less than one weight percent addition of a polysaccharide biopolymer has been able to convert an ink optimized for use with antisolvent spin coating in an inert environment into a quench free ink capable of being processed in open-air via a scalable deposition method. Without wishing to be bound by theory, an important implication of this work is to accelerate the commercialization of PVSK solar cells through the usage of a single, common PVSK solvent. In doing so, without wishing to be bound by theory, we can enable a scalable manufacturing process of robust perovskite solar cells by having shown how crystallization theory can be leveraged to improve morphology, stability, and durability.
All of the materials were purchased and used as received unless otherwise stated. Methylammonium Iodide (MAI, >99.99%), CH3NH3I, was purchased from GreatCell Solar. Lead (II) Iodide, PbI2 (99.99%), was purchased from TCI. Gellan gum was sourced from Alfa Aesar and was oven dried at 80° C. for 3 days before use and then stored in a nitrogen dry box. The solvent, dimethyl sulfoxide (DMSO, ≥99%), was purchased from Sigma Aldrich. Gellan gum powder was purchased from Alfa Aesar.
The halide PVSK (CH3NH3PbI3) precursor solution was prepared by mixing MAI and PbI2 in a molar ratio of 1:1 in 1 mL of DMSO in a nitrogen glovebox. This solution was then mixed with a stir bar at 80° C. for 30 minutes. This stock solution was pipetted into separate vials for further DMSO dilution to 0.5M and the addition of various amounts of dried gellan gum, such as 0.18% and 0.56% weight percent of the perovskite precursors. The gellan gum MAPI inks were heated for 2 more hours at 80° C. while being mixed continuously with a stir bar until complete visual dissolution of the gellan gum particles.
Plain or patterned ITO glass substrates were washed with detergent and rinsed with deionized water before being sonicated sequentially in acetone and isopropanol for 5 minutes each. The substrates were dried with a nitrogen gun and UV-ozone treated for 10 minutes before coating. When investigating gum concentrations of 0.56% or less, a ten-minute substrate pre-heating period was allowed if coating on a heated substrate which did not exceed 55° C. The blade coater gap varied from 100-300 μm to accommodate for variations in the glass substrate and ink viscosity while blade speeds ranged from 2.5 mm/s to 30 mm/s. Spin coating was done in a nitrogen glovebox at 4000 rpm for 30 seconds with chlorobenzene as the antisolvent. All films were annealed at 100° C. for 25 minutes.
Bruker Multimode 8 Atomic Force Microscope was used to image the surface of our samples. The images were recorded at a 5 μm×5 μm resolution with a scan rate of 1 Hz and 256 lines/sample. The Keyence VHX-7000 Microscope was used to verify the morphology of the sample using the transillumination settings, and a smartphone was used to record macroscale 1×1 in images.
Illuminated lock-in thermography (ILIT) uses pulsed light and thermal imaging over time to produce thermal amplitude maps of a sample [29,30]. The amplitude of the thermal emission is directly related to the amount of non-radiative recombination occurring at the point; the thermal emission is influenced by the light absorption and lateral carrier transport within the material [30]. ILIT was measured using a modified ThermoSensorik GmbH ThermoSensor. The tool's 4-quadrant power supply was connected to a green LED array from Brightspot Automation which was used to pulse light onto the sample. The image resolution is approximately 5-μm per pixel. Due to uncertainties in the location of the light relative to the sample and in calibration, the absolute amplitude (in mK) is not used in the thermal amplitude maps. Rather, a relative measure of the maximum observed thermal amplitude is used. In this way, we comment on the distribution of thermal emission across the sample, which changes with film morphology, rather than an exact measure of heating at a given point.
The I-V responses of the samples were measured using PAIOS, an all-in-one measurement equipment for photovoltaic devices and LEDs, and photoluminescence (PL) was measured using an in-house BLACK-Comet UV-Vis Spectrometer from StellarNet with a laser wavelength of 425 nm.
The samples were aged in the Thermotron Model SM-8-8200 Environmental Test Chamber, and the fracture data was collected through the use of a double cantilever beam set up which features the Delaminator Adhesion Test System in the configuration. For fracture testing, sandwich-like structures were assembled with perovskite films coated on ITO glass being covered with a protective layer of polymethyl methacrylate (PMMA) which was then epoxied to an additional glass slide. A manually created pre-crack was formed to assist initial crack formation at the perovskite layer during the uniaxial cyclic loading process, and the average Gc was calculated from averaging multiple critical load values from the resulting load-displacement curve as the crack propagated along the length of the sample.
Grazing incidence wide angle X-ray scattering (GIWAXS) measurements were performed on a Xenocs Xeuss 3.0 SAXS/WAXS instrument. A GeniX3D Cu High Flux Very Long (HFVL) focus source was used to produce an 8 KeV Cu K alpha collimated X-ray beam with a wavelength of 1.541891 Å (generated at 50 kV and 0.6 mA). A windowless EIGER2 R 1M DECTRIS Hybrid pixel photon counting detector was used to collect the scattering signal at the sample-to-detector distance of 80 mm to cover a Q range between ˜0.5 Å-1 and ˜3.5 Å-1. Default GIWAXS lineup and rectangular beam (0.8 mm×1.2 mm) were used for measuring each sample. Grazing incidence angles were set as 0.2° and 1º. Measuring time was 30 mins for each sample. Q representation images (Qx vs. Qz) were reduced from the obtained images from the 2D detector.
Perovskite materials hold the potential for making high-efficiency, low-cost solar devices through solution processing of Earth abundant materials. Research utilizes spin coating as a means of reliable application, but this method lacks the scalability demanded in industry. For this reason, blade coating has been utilized as a conduit for scalable roll-to-roll fabrication of perovskite thin films; however, unmodified inks prove unsuitable for this meniscus governed process. Gellan gum, a biopolymer from the food industry, enables scalable, open-air manufacturing by altering fluid dynamics and free energy of formation to vary supersaturation rates.
Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the following claims.
Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the following claims.
This application claims priority to U.S. Provisional Application No. 63/458,395, filed on Apr. 10, 2023, the entire contents of which are incorporated herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63458395 | Apr 2023 | US |
