Method for preparing perovskite solar cells (PSCs) and the resulting PSCs

Abstract

Some embodiments of the present invention include an inventive method for preparing a perovskite solar cell (PSC). In certain embodiments, the method includes dissolving a functionalization material (e.g., a material that has been functionalized with one or more functionalizing compounds) in a solvent, depositing a deposition composition onto a perovskite layer, the deposition composition including the dissolved functionalization material, heating the deposition composition, and optionally removing some or all of the one or more functionalizing compounds from the deposition composition. Additional embodiments of the present invention are also disclosed herein.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 261,441, entitled "Solar cells, methods for making, and methods for using," filed September 21, 2021, which is incorporated by reference in its entirety.

[0002] Government Rights This invention was made with government support under DE-EE0008752 awarded by the U.S. Department of Energy. The Government has certain rights in this invention. [Background technology]

[0003] Several perovskite solar cells (PSCs) are known. However, fabrication methods for PSCs have limitations, such as, but not limited to, solvent incompatibility, processing temperatures, etc., which can result in damage to the perovskite layer.

[0004] Certain embodiments of the present invention address one or more of the deficiencies mentioned above. Some embodiments of the present invention include an inventive method for preparing a perovskite solar cell (PSC). In a particular embodiment, the method includes dissolving a functionalization material (e.g., a material that is functionalized with one or more functionalizing compounds) in a solvent, depositing a deposition composition on a perovskite layer, the deposition composition including the dissolved functionalization material, heating the deposition composition, and optionally removing some or all of the one or more functionalizing compounds from the deposition composition. Additional embodiments of the present invention are also disclosed herein. Summary of the Invention [Means for solving the problem]

[0005] Some embodiments of the invention include a method for preparing a perovskite solar cell (PSC), the method comprising dissolving a functionalization material in a solvent, the functionalization material being a material that has been functionalized with one or more functionalizing compounds; depositing a deposition composition on a perovskite layer, the deposition composition comprising the dissolved functionalization material; heating the deposition composition; and optionally removing some or all of the one or more functionalizing compounds from the deposition composition.

[0006] In other embodiments, the functionalized material is an organic material, a metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 The BM may comprise one or more of:

[0007] In certain embodiments, the material includes one or more doping substances, while in other embodiments, the one or more doping substances include Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo.

[0008] In some embodiments, the functionalization material is an organic material, a metal oxide, a doped metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiO x , C 60 , C 70 , P.C. 61 B.M., P.C. 71 In yet another embodiment, the functionalized material comprises one or more of a metal oxide, a doped metal oxide, TiO2, SnO2, NiO, or a combination of these. x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiO x , C 60, C 70 , P.C. 61 B.M., P.C. 71 In yet another embodiment, the functionalized material comprises one or more of TiO2, SnO2, NiO, BM, or fullerenes. x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, or Cu:NiO x Contains one or more of the following:

[0009] In certain embodiments, the functionalized material is SnO2, NiO x , Y:SnO2, or Cu:NiO x Contains one or more of the following:

[0010] In some embodiments, the one or more functionalizing compounds include (1)R 1a -CO-OH(I), or a salt thereof, wherein R 1a is substituted or unsubstituted alkyl, (I) or a salt thereof; (2)R 2a -O-CS2 - M + 2a (II) In the formula, R 2a is a substituted or unsubstituted alkyl; M + 2a is a cation; (II); [ka] And, In the formula, X3 is an anion and R 3a , R 3c , R 3d , and R 3e are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R 3b is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted Lewis base, quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; (IIIa) or (IIIb); [ka] And, In the formula, X4 is an anion and R 4a , R 4c , R 4d , R 4e , R 4f , and R 4g are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R 4b is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted Lewis base, quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; (IVa) or (IVb); [ka] And, In the formula, R 5a , R 5b , and R 5c are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; (V); [ka] And, In the formula, R 6b , R 6c , and R 6d are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R 6a is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, R 6a The substituted alkyl is optionally substituted with one or more substituted or unsubstituted Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; R 6a The substituted aryl is optionally substituted with one or more substituted or unsubstituted Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; (VI); or (7)R 7a-NH-CS2 - M + 7a (VII), In the formula, R 7a is a substituted or unsubstituted alkyl; M + 2a is one or more of (VII), which is a cation.

[0011] In certain embodiments, R 1a is a substituted or unsubstituted C1-C8 alkyl, methyl, ethyl, propyl, or butyl. In other embodiments, R 2a is a substituted or unsubstituted alkyl C1-C 36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl, or M + 2a is Na + , K + , or Li + In yet other embodiments, X3 is Cl - , Br - , I - , BF4 - , PF6 - , or CF3SO3 - or R 3a , R 3c , R 3d , and R 3e are the same or different and are H, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted phenyl, or R 3b is H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted phenyl, -C(O)H, -C(O)OH, -C(O)NHR 3f , -CH2OR 3f , -CH2NHR 3f , a quaternary nitrogen salt, a carboxylate, a xanthate, an alkoxide, or a thiolate; 3f In yet another embodiment, X4 is H, substituted or unsubstituted C1-C8 alkyl, or a combination thereof. - , Br - , I - , BF4 -, PF6 - , or CF3SO3 - or R 4a , R 4c , R 4d , R 4e , R 4f , and R 4g are the same or different and are H, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted phenyl, or R 4b is H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted phenyl, -C(O)H, -C(O)OH, -C(O)NHR 4h , -CH2OR 4h , -CH2NHR 4h , a quaternary nitrogen salt, a carboxylate, a xanthate, an alkoxide, or a thiolate; 4h is H, substituted or unsubstituted C1-C8 alkyl, or a combination thereof. In certain embodiments, R 5a , R 5b , and R 5c are the same or different and are H, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted phenyl. In other embodiments, R 6b , R 6c , and R 6d are the same or different and are H, substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted phenyl, or R 6a is H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted phenyl, R 6a A substituted alkyl group may optionally include one or more of -C(O)H, -C(O)OH, -C(O)NHR 6e , -CH2OR 6e , -CH2NHR 6e , quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; R 6a A substituted aryl may optionally include one or more of -C(O)H, -C(O)OH, -C(O)NHR 6e , -CH2OR 6e , -CH2NHR 6e, quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; R 6e is H, substituted or unsubstituted C1-C8 alkyl, or a combination thereof. In other embodiments, R 7a is a substituted or unsubstituted alkyl C1-C 36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl, or M + 7a is Na + , K + , or Li + or a combination thereof.

[0012] In some embodiments, Formula (IIIb) is [ka] It is.

[0013] In certain embodiments, formula (V) is selected from triarylamine (TAA), substituted TAA, triphenylamine, substituted triphenylamine, triethylamine, and substituted triethylamine.

[0014] In other embodiments, the functionalization material is a metal oxide, a doped metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiO x , C 60 , C 70 , P.C. 61 B.M., P.C. 71 or fullerene, each independently comprising: (i) one or more of: 1a is C1-C4 alkyl; or a salt thereof; (ii) one or more of the formula (I) in which R 2a is C1-C 27 is alkyl, M + 2a is Na + , K + , or Li+ In yet another embodiment, the functionalized material is a metal oxide, a doped metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 or fullerene, each independently functionalized with one or more of formula (I) or salts thereof, wherein R 1a is C1-C4 alky. In yet other embodiments, the functionalized material is TiO2, ZnO, Y:SnO2, Cu:NiO x , NiO x or SnO2, each of which is independently selected from acetate, propionate, triethylamine, NaC 18 Alkyl xanthate, Na C 12 In certain embodiments, the functionalized material is TiO, ZnO, NiO, or a combination thereof. x or SnO2, each independently functionalized with one or both of acetate or propionate.

[0015] In some embodiments, the solvent is a protic solvent, anhydrous protic solvent, anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, anhydrous C 1-10 The solvent may include alcohol, THF, dimethyl ether, diethyl ether, anhydrous ether, ether, chlorobenzene (CB), or a combination thereof.

[0016] In certain embodiments, the depositing step is performed by one or more of blade coating, spin coating, slot die, gravure, flexography, spraying, or inkjet, hi yet other embodiments, the depositing step is performed by blade coating.

[0017] In some embodiments, the heating step comprises annealing or intense pulsed light (IPL). In other embodiments, the heating step comprises heating at about 80° C. to about 120° C. for about 5 to about 20 minutes. In yet other embodiments, the heating step removes some or all of the one or more functionalizing compounds.

[0018] In some embodiments, the removing step occurs, hi other embodiments, the removing step occurs by heat or by intense pulsed light (IPL).

[0019] In other embodiments, (i) the heating step removes a portion of the one or more functionalizing compounds, and (ii) the removing step occurs to further remove some or all of the remaining one or more functionalizing compounds.

[0020] In some embodiments, the perovskite layer is CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, CH3NH3SnX3, or Cs a (CH5NH3) b (CH3NH3) c PbI 3(1-y) Br 3y wherein X is a halogen which may be the same or different between or within each formula; a is from about 0 to about 0.5; b is from about 0 to about 0.8; c is from about 0 to about 0.8; and y is from about 0 to about 1.

[0021] In certain embodiments, the PSC is a pin-type device. In other embodiments, the PSC is a nip-type device.

[0022] In some embodiments, the perovskite layer is part of a structure that further comprises one or more of an anode, a hole transport layer (HTL), or a cathode. In other embodiments, the perovskite layer is part of a structure that further comprises one or more of an anode, an electron transport layer (ETL), or a cathode.

[0023] In certain embodiments, the method further comprises adding a cathode. In other embodiments, the method further comprises adding a cathode, and the method for adding the cathode is screen printing, thermal evaporation, sputtering, or atomic layer deposition. In yet other embodiments, the method further comprises adding a cathode, and the method for adding the cathode is thermal evaporation. In some embodiments, the method further comprises adding a cathode, and the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu. In certain embodiments, the method further comprises adding a cathode, and the cathode is Ag, Al, or Cu.

[0024] In some embodiments, the PSC has an open circuit voltage (Voc) of about 0.7 V to about 1.3 V. In certain embodiments, the PSC has a fill factor (FF) of about 35% to about 80%. In other embodiments, the PSC has a fill factor (FF) of about 10 mA / cm 2 ~Approx. 25mA / cm 2 current density (J sc In yet another embodiment, the PSC has a power conversion efficiency (PCE) of about 4% to about 20%.

[0025] In some embodiments, the PSC is a flexible PSC.

[0026] Some embodiments of the invention include a PSC made according to any method disclosed herein. In certain embodiments, the PSC includes an anode, a hole transport layer (HTL), an electron transport layer (ETL) and a perovskite layer prepared according to any method disclosed herein (e.g., original claim 1), and a cathode. In certain embodiments, the anode is ITO / glass or FTL / glass. In other embodiments, the HTL is NiO x, PTAA, or PTAA / PFN. In some embodiments, the perovskite layer is one or more of CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, or CH3NH3SnX3, where X is a halogen that may be the same or different between or within each formula. In still other embodiments, the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu. In yet other embodiments, the cathode is Ag, Al, or Cu.

[0027] Some embodiments of the invention include a PSC made according to any method disclosed herein. In certain embodiments, the PSC includes an anode, an ETL, an HTL and a perovskite layer prepared according to any method disclosed herein (e.g., original claim 1), and a cathode. In some embodiments, the anode is ITO / glass or FTL / glass. In other embodiments, the ETL is SnO2, TiO2, or ZnO. In still other embodiments, the perovskite layer is one or more of CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, or CH3NH3SnX3, where X is a halogen that may be the same or different between or within each formula. In certain embodiments, the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu. In still other embodiments, the cathode is Ag, Al, or Cu.

[0028] Other embodiments of the present invention are also contemplated herein.

[0029] This 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 the necessary fee.

[0030] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the invention. The invention may be better understood by reference to one or more of these drawings in combination with the description of specific embodiments presented herein. [Brief description of the drawings]

[0031] [Figure 1] Schematic of the synthesis of hydrous SnO2 (a), functionalization of hydrous SnO2 with acetic acid to give SnO2-A (b), preparation of a stable colloidal dispersion in absolute ethanol (c), XRD diffraction pattern (d), and FTIR spectra of hydrous SnO2 and SnO2-A (e). [Diagram 2] XRD patterns (a), photoluminescence spectra (b), and time-resolved photoluminescence data (c) of CH3NH3PbI3 perovskite films before and after deposition of SnO2-A. [Diagram 3] Schematic of blade coating of SnO2-A on perovskite (a) and cross-sectional SEM image of the full device (b). [Figure 4] Device structure of pin PSC with SnO2-A on the surface of the perovskite film (a), J-V curve of the champion device (b), and the corresponding photovoltaic parameters (c). [Diagram 5] Stability study JV characteristics of unencapsulated pin devices before (1) and after (2) storage in a nitrogen flow box for 40 days. [Figure 6] Preparation of NiOx ink. [Figure 7] SEM images of NiOx particles. (a) As-prepared NiOx powder showing particle aggregation. (b) NiOx film prepared using 0X ink showing uniform dispersion of small particles. Scale bar is 1 μm. [Figure 8](a) UV-Vis of 12X ligand, 12X ink, and 0X ink in the same solvent system in a 1 mm quartz cell showing the coordination of 12X to NiOx in the ink. (b) FT-IR of 12X ligand as a powder and 12X ink as a film showing the coordination of 12X to NiOx in the ink. [Figure 9] (a) TGA of the 12X ligand as a solid and the 12X ink as a thick film confirming the decomposition of the xanthate at temperatures above 300 °C. (b-d) SEM images of 0X, 12X, and 18X films prepared by blade coating showing the change in film uniformity in the presence of the xanthate ligand. Scale bar is 5 μm. [Figure 10] (a–d) Statistical comparison of photovoltaic parameters of 0.25 cm2 cells prepared with 0X–18X inks. (e) Schematic of the pin device stack with the assumed energy alignment (eV). [Figure 11] JV curves of 1 cm2 devices prepared with 0X and 18X inks. [Figure 12] (a) Schematic of the nip device. (b) Optical image of the 0X coated perovskite. (c) Optical image of the perovskite film before NiOx coating. (d) PXRD of the as-prepared perovskite film (red) and the perovskite film after deposition of the 0X ink (grey) showing the formation of a new peak at 9.5°. [Figure 13] PXRD of Cu-doped and undoped NiOx nanoparticles. The extra peak at 29 is sodium nitrate and is completely removed by further washing. [Figure 14] Change in mean particle size upon one week of intact aging. [Figure 15] JV curves of the highest preformed NiOx and Cu doped films. Values ​​are summarized in Table C1. [Figure 16](a) Energy dispersive X-ray spectroscopy (EDS) spectrum of Y:SnO2. (b) XRD patterns of pristine SnO2 and Y:SnO2. Elemental mapping of (c) tin, (d) oxygen, and (e) yttrium present in the Y:SnO2 nanoparticles. [Figure 17] XPS spectra of SnO2 and Y:SnO2 film. (a) XPS measured spectrum, (b) high-resolution XPS spectrum of Sn 3d (curves represent unfitted Sn 3d curve (solid line), fitted curve (medium dashed line), fitted curve for Sn 3d5 / 2 (long dashed line), and fitted curve for Sn 3d3 / 2 (short dashed line)), and (c) XPS spectrum Y 3d. [Figure 18] (a) Functionalization of Y:SnO2 and dilution of functionalized Y:SnO2 in absolute ethanol, (b) schematic of blade coating, (c) SEM image of the perovskite film before Y:SnO2 deposition, and (d) SEM image of the perovskite film after Y:SnO2 deposition. [Figure 19] (a) XRD diffraction patterns and (b) UV-Vis spectra of the perovskite films before and after deposition of SnO2-A. [Figure 20] Steady-state PL spectra of PET / perovskite, PET / perovskite / SnO2-A and PET / perovskite / Y:SnO2-A samples. [Figure 21] Device performance statistics versus yttrium doping concentration. Photovoltaic parameters (a) VOC, (b) JSC, (c) FF, and (d) PCE. [Figure 22] (a) Digital image of f-PSC, (b) JV curve of Champion 0.1 cm2 device, and (c) JV hysteresis of Y:SnO2-A device. [Figure 23] An exemplary scheme for preparing Y-doped SnO2. [Figure 24] Analysis of JV characteristics of Y doped SnO2-average current density (Jsc) and fill factor (FF) percentage. [Diagram 25]Analysis of JV characteristics of Y doped SnO2-potential (VOC) and power conversion efficiency (PCE) percent. [Figure 26] (a) PXRD of MAPI as deposited with a NiOx top film. (b) Photoemission spectra of MAPI, MAPI / NiOx, and MAPI / NiOx / PA. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Although embodiments embodying the general inventive concept may take a variety of forms, various embodiments are described herein with the understanding that the disclosure should be considered merely as illustrative and that the general inventive concept is not intended to be limited to the disclosed embodiments.

[0033] Some embodiments of the present invention include an inventive method for preparing a perovskite solar cell (PSC). In certain embodiments, the method includes dissolving a functionalization material (e.g., a material that has been functionalized with one or more functionalizing compounds) in a solvent, depositing a deposition composition onto a perovskite layer, the deposition composition including the dissolved functionalization material, heating the deposition composition, and optionally removing some or all of the one or more functionalizing compounds from the deposition composition. Additional embodiments of the present invention are also disclosed herein.

[0034] As used herein (unless otherwise specified), the term "alkyl" refers to a monovalent, straight or branched hydrocarbon chain. For example, the term "C1-C7 alkyl" or "C1-C4 alkyl" refers to a straight or branched saturated hydrocarbon group having 1 to 7 (e.g., 1, 2, 3, 4, 5, 6, or 7) or 1 to 4 (e.g., 1, 2, 3, or 4) carbon atoms, respectively. Examples of C1-C7 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, n-hexyl, and n-septyl. Examples of C1-C4 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, and t-butyl.

[0035] As used herein (unless otherwise specified), the term "alkoxy" means any of the above alkyl groups attached to the remainder of the molecule by an oxygen atom (alkyl-O-). Examples of alkoxy groups include, but are not limited to, methoxy (sometimes referred to as MeO-), ethoxy, isopropoxy, propoxy, and butyloxy.

[0036] As used herein (unless otherwise specified), the term "aryl" refers to a monovalent, monocyclic or bicyclic, 5-, 6-, 7-, 8-, 9-, 10-, 11-, or 12-membered aromatic hydrocarbon group when unsubstituted. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, tolyl, and xylyl. In the case of bicyclic aryls, which are designated as substituted, one or both rings can be substituted.

[0037] As used herein (unless otherwise specified), the term "halogen" means monovalent Cl, F, Br, or I.

[0038] As used herein (unless otherwise specified), the term "heteroatom" means an atom selected from a nitrogen atom, an oxygen atom, or a sulfur atom.

[0039] As used herein (unless otherwise specified), the term "hydroxy" or "hydroxyl" denotes the presence of a monovalent --OH group.

[0040] As used herein (unless otherwise specified), the term "Lewis base" refers to any chemical species having a filled orbital containing an electron pair that is not involved in bonding but can form a coordinate bond (i.e., a two-center, two-electron covalent bond in which both electrons come from the same atom) with another chemical (e.g., a chemical with an empty orbital that can accept an electron pair). Some Lewis bases can be traditional amines (e.g., ammonia and alkylamines) or pyridine and its derivatives. Some classes of Lewis bases are (a) amines (e.g., NR3, where R is independently H, alkyl, or aryl), (b) phosphines (e.g., PR3, where R is independently alkyl or aryl), or (c) compounds of O, S, Se, and Te in the oxidation state -2 (e.g., water, ethers, or ketones). Other examples of Lewis bases include (a) H - and F - (b) simple anions such as H2O, NH3, and HO - and CH3 - (c) complex anions such as sulfate, and (d) electron-rich π-systems such as ethyne, ethene, and benzene. Other examples of Lewis bases include EtN, quinuclidine, pyridine, acetonitrile, EtO, THF, acetone, EtOAc, DMA, DMSO, tetrahydrothiophene, and trimethylphosphine. The Lewis base can be a monovalent moiety. The Lewis base can be substituted or unsubstituted.

[0041] As used herein (unless otherwise specified), the term "substituted" (e.g., as in substituted alkyl) means that one or more hydrogen atoms of a chemical group (having one or more hydrogen atoms) may be replaced by one or more non-hydrogen substituents selected from a specified selection. The substitution may occur at one or more positions. The term "optionally substituted" means that one or more hydrogen atoms of a chemical group (having one or more hydrogen atoms) may, but need not, be replaced. Non-hydrogen substituents include, but are not limited to, halogen (e.g., F, Cl, Br, or I), hydroxy (-OH), methanoyl (-COH), -COCH, carboxy (-COH), ethynyl (-CCH), cyano (-CN), sulfo (-SOH), methyl, ethyl, perfluoromethyl, perfluoroethyl, amine, alcohol, ether, thiol, thioether, amide, Lewis base, quaternary nitrogen salt, carboxylate, xanthate, alkoxide, thiolate, aldehyde, C(O)OH, C(O)NHR, -CHOR, or -CHNHR, where R is H, unsubstituted. It can be an alkyl (e.g., a C1, C2, C3, C4, C5, C6, C7, or C8 alkyl) or an alkyl (e.g., a C1, C2, C3, C4, C5, C6, C7, or C8 alkyl) substituted (e.g., with one or more of halogen (e.g., F, Cl, Br, or I), hydroxy (-OH), methanoyl (-COH), -COCH3, carboxy (-CO2H), ethynyl (-CCH), cyano (-CN), sulfo (-SO3H), methyl, ethyl, perfluoromethyl, perfluoroethyl, amine, alcohol, ether, thiol, thioether, amide, or aldehyde).

[0042] Methods for preparing perovskite solar cells (PSCs) Some embodiments of the present invention include a method for preparing a perovskite solar cell (PSC) as disclosed herein. In certain embodiments, the method includes: (a) dissolving a functionalization material in a solvent, where the functionalization material is a material that has been functionalized with one or more functionalizing compounds; (b) depositing (e.g., layering) a deposition composition (e.g., ink) on a perovskite layer, where the deposition composition includes the dissolved functionalization material; (c) heating the deposition composition on the perovskite layer; and (d) optionally removing some or all of the one or more functionalizing compounds.

[0043] In some embodiments, the material of the functionalization material can be any suitable material. In certain embodiments, the material of the functionalization material is an organic material, a metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 It may be one or more of: NiO, BM, or fullerenes. x is NiO(Ni 2+ ), Ni2O3(Ni 3+ ) and / or a mixture of NiO and Ni2O3. In some embodiments, the functionalized material may be an organic material, a metal oxide, a doped metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiO x , C 60 , C 70 , P.C. 61 B.M., P.C. 71 In other embodiments, the material may be doped using one or more of any suitable doping substances (e.g., Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo). The doped material may be Cu:NiO xIn some embodiments, the material may be, but is not limited to, SnO2, NiO x , Cu:NiO x , or Y:SnO2. In some embodiments, the material (e.g., the doped material) may be functionalized with one or more functionalizing compounds (e.g., one or more suitable functionalizing compounds) (e.g., the material is bonded to one or more functionalizing compounds using covalent and / or ionic bonds). In other embodiments, the material (e.g., the doped material) may be functionalized with one or more of the following functionalizing compounds (e.g., one or more selected from formulas (I), (II), (IIIa), (IIIb), (IVa), (IVb), (V), (VI), or (VI)) (e.g., the material is bonded to one or more functionalizing compounds using covalent bonds, ionic bonds, or both).

[0044] (1)R 1a -CO-OH(I), or a salt thereof (e.g., where the cation is, for example, Na + , K + , Li + , Mg 2+ , Ca 2+ or any suitable cation, 1a may be substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl, or methyl, ethyl, propyl, or butyl); (I); (2)R 2a -O-CS2 - M + 2a (II) In the formula, R 2a is a substituted or unsubstituted alkyl (e.g., C1-C 18 Alkyl, C1-C 27 Alkyl, C1-C 36 Alkyl, or C1, C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14, C 15 , C 16 , C 17 , C 18 , C 19 , C 20 , C 21 , C 22 , C 23 , C 24 , C 25 , C 26 , C 27 , C 28 , C 29 , C 30 , C 31 , C 32 , C 33 , C 34 , C 35 , or C 36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl), M + 2a is any suitable cation (e.g., Na + , K + , or Li + ), (II), [ka] (e.g., imidazole and its imidazolium salts) where X3 is Cl - , Br - , I - , BF4 - , PF6 - , CF3SO3 - or any suitable anion, (IIIa) or (IIIb). 3a , R 3c , R 3d , and R 3e R can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). 3b is H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), substituted or unsubstituted aryl (e.g., phenyl), (e.g., -C(O)H, C(O)OH, -C(O)NHR3f , -CH2OR 3f , or -CH2NHR 3f R may be a substituted or unsubstituted Lewis base (e.g., with an amine, alcohol, ether, thiol, thioether, amide, or aldehyde), or a charged functional group (e.g., a quaternary nitrogen salt, a carboxylate, a xanthate, an alkoxide, or a thiolate). 3f can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl). Some examples of formula (IIIb) include, but are not limited to, the following: [ka] In the formula, R 3c is H or unsubstituted alkyl (e.g., C, C, C, C, C, C, C, C, or C alkyl), and R 3f is H or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), and X3 is Cl - , Br - , I - , BF4 - , PF6 - , or CF3SO3 - and [ka] (e.g., benzimidazole and its benzimidazolium salts). X4 is Cl - , Br - , I - , BF4 - , PF6 - , CF3SO3 - , or any suitable anion. 4a , R 4c , R 4d , R 4e , R 4f , and R 4gR can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). 4b is H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), substituted or unsubstituted aryl (e.g., phenyl), (e.g., -C(O)H, -C(O)OH, -C(O)NHR 4h , -CH2OR 4h , or -CH2NHR 4h R may be a substituted Lewis base (such as an amine, alcohol, ether, thiol, thioether, amide, or aldehyde), or a charged functional group (such as a quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate). 4h can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl); [ka] R 5a , R 5b , and R 5c can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). Examples of formula (V) include triarylamine (TAA), substituted TAA, triphenylamine, substituted triphenylamine, triethylamine, and substituted triethylamine; [ka] (e.g., 2-pyrrolidinone), R 6b , R 6c , and R 6d R can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). 6aR can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), substituted or unsubstituted aryl (e.g., phenyl). 6a The substituted alkyl is optionally substituted (e.g., -C(O)H, -C(O)OH, -C(O)NHR 6e , -CH2OR 6e , or -CH2NHR 6e R may be substituted with one or more Lewis bases (e.g., amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes) or charged functional groups (e.g., quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates). 6a Substituted aryl is optionally substituted (e.g., -C(O)H, -C(O)OH, -C(O)NHR 6e , -CH2OR 6e , or -CH2NHR 6e R may be substituted with one or more Lewis bases (e.g., amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes) or charged functional groups (e.g., quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates). 6e can be H, substituted or unsubstituted alkyl (e.g., C1, C2, C3, C4, C5, C6, C7, or C8 alkyl), or (7)R 7a -NH-CS2 - M + 7a (VII), In the formula, R 7a is a substituted or unsubstituted alkyl (e.g., C1-C 18 Alkyl, C1-C 27 Alkyl, C1-C 36 Alkyl, or C1, C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14 , C 15 , C 16 , C 17 , C 18 , C 19 , C20 , C 21 , C 22 , C 23 , C 24 , C 25 , C 26 , C 27 , C 28 , C 29 , C 30 , C 31 , C 32 , C 33 , C 34 , C 35 , or C 36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl), M + 7a is any suitable cation (e.g., Na + , K + , or Li + ).

[0045] In certain embodiments, the functionalization material is an organic material, a metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 In yet other embodiments, the functionalized material includes one or more of a metal oxide, a doped metal oxide, TiO2, SnO2, NiO, or a BM, each of which may be independently functionalized with one or more of R-CO-OH, where R may be a C1-C4 alkyl or salt thereof. x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiO x , C 60 , C 70 , P.C. 61 B.M., P.C. 71 or fullerene, each independently being one or more of (i) formula (I), or a salt thereof, wherein R 1a is one or more of compounds (i), (ii) formula (II), wherein R2a is C1-C 27 is alkyl, M + 2a is Na + , K + , or Li + In yet another embodiment, the functionalized material is a metal oxide, a doped metal oxide, TiO2, SnO2, NiO x , CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 or fullerene, each independently functionalized with one or more of formula (I) or salts thereof, wherein R 1a is C1-C4 alkyl. In certain embodiments, the functionalized material is TiO2, ZnO, Y:SnO2, Cu:NiO x , NiO x or SnO2, each of which is independently selected from acetate, propionate, triethylamine, NaC 18 Alkyl xanthate, Na C 12 The functionalized material is functionalized with alkyl xanthate, Na C4 xanthate, Na xanthate, or a combination thereof. In certain embodiments, the functionalized material is TiO2, ZnO, Y:SnO2, Cu:NiO x , NiO x or SnO2, each of which is independently selected from acetate, propionate, triethylamine, NaC 18 Alkyl xanthate, Na C 12 In other embodiments, the functionalized material is TiO2, ZnO, NiO x or SnO2, each independently functionalized with one or both of acetate or propionate. In some embodiments, the functionalized material is 18 Acetate-functionalized NiOx Does not include.

[0046] In other embodiments, the solvent is any suitable protic solvent, any suitable anhydrous protic solvent, anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, anhydrous C1, C2, C3, C4, C5, C6, C7, C8, C9, or C 10 The solvent may include any suitable solvent, such as, but not limited to, alcohol, THF, dimethyl ether, diethyl ether, any suitable anhydrous ether, any suitable ether, chlorobenzene (CB), or combinations thereof. In some embodiments, the solvent includes anhydrous ethanol, anhydrous isopropanol, chlorobenzene (CB), or combinations thereof. In other embodiments, the solvent does not decompose (e.g., does not significantly and / or deleteriously decompose) the perovskite layer. In some embodiments, the solvent does not include CB. In some embodiments, the solvent does not include isopropanol.

[0047] In certain embodiments, the deposition composition includes a dissolved functionalization material, and the dissolved (e.g., completely dissolved or partially dissolved) functionalization material includes the functionalization material and a solvent. In some embodiments, the functionalization material can be completely dissolved in the solvent. In still other embodiments, the functionalization material can be partially dissolved in the solvent (e.g., at least 80%, at least 90%, or at least 99% by weight of the total functionalization material is dissolved, or 99.9%, 99%, 98%, 95%, 90%, 85%, or 80% by weight of the total functionalization material is dissolved). In certain embodiments, the concentration of the functionalizing material in the deposition composition can be any suitable concentration (e.g., 0.01-90.0, 0.01-50.0, 0.01-10.0, 0.1-5.0, 0.5-3.0% (m / v), or 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 1.10, 1.12, 1.14, 1.16, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.30, 1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.39, 1.39, 1.34, 1.35, 1.39 ... 5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.5, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, or 90.0% (m / v) (or g / 100 mL). In other embodiments, the concentration of the functionalizing material in the deposition composition can be any suitable concentration (e.g., 0.01-99.9, 0.01-50.0, 0.01-10.0, 0.1-5.0, 0.5-3.0 wt / wt%, or 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 ...0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2 4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.5, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, 90.0, 95.0, 99.0, or 99.9 wt / wt%).In yet other embodiments, the deposition composition (e.g., ink) further comprises one or more of any suitable doping substances (e.g., Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo). As described herein, the deposition composition can include a functionalized material, which can be a material that is functionalized with one or more functionalizing compounds. In other embodiments, the material can include a material that is doped with one or more of any suitable doping substances (e.g., Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo). The doped material can be Cu:NiO. x or Y:SnO2, but is not limited to these. In some embodiments, the material (e.g., the doped material) can be functionalized with one or more suitable functionalizing compounds (e.g., the material is bonded to one or more functionalizing compounds using covalent and / or ionic bonds). In some embodiments, the deposition composition can be C dissolved in CB. 18 Acetate-functionalized NiO x Does not include.

[0048] In other embodiments, the depositing may be performed by one or more of any suitable deposition methods. In still other embodiments, the depositing may be performed by one or more of blade coating, spin coating, pulsed laser deposition, electron beam evaporation, spray pyrolysis, co-sputtering, atomic layer deposition, slot die, gravure, flexography, spray, or inkjet. In other embodiments, the depositing may be performed by one or more of blade coating, spin coating, slot die, gravure, flexography, spray, or inkjet. In yet other embodiments, the depositing may be performed by blade coating. In certain embodiments, the deposition composition is layered on the perovskite layer. In some embodiments, the deposition composition is layered on the perovskite layer such that the perovskite layer is at least partially covered by the deposition composition or completely covered by the deposition composition. In other embodiments, the solvent does not decompose (e.g., does not significantly and / or deleteriously decompose) the perovskite layer during deposition. In certain embodiments, the depositing does not use vacuum techniques, such as, but not limited to, atomic layer deposition, sputtering, or evaporation.

[0049] In some embodiments, the heating can be accomplished using any suitable heating method, such as, but not limited to, a hot plate, an oven (e.g., a convection oven), or intense pulsed light (IPL) (details and examples of IPL methods are disclosed in U.S. Patent No. 10,950,794, issued March 16, 2021, and incorporated herein by reference in its entirety). In still other embodiments, the heating includes annealing (e.g., by IPL). In still other embodiments, the heating includes heating by intense pulsed light (IPL). In still other embodiments, the heating includes heating (e.g., using a hot plate, an oven (e.g., a convection oven), or IPL) at about 80°C to about 120°C (e.g., about 80°C, about 90°C, about 100°C, about 110°C, or about 120°C) for about 5 to about 20 minutes (e.g., about 5, about 8, about 10, about 12, about 15, or about 20 minutes). In still other embodiments, the heating may heat other layers of the PSC (or the PSC being made). In yet other embodiments, the heating does not significantly heat other layers of the PSC (or the PSC being made). In certain embodiments, the heating may remove some or all of the one or more functionalizing compounds. In other embodiments, the removal of some of the one or more functionalizing compounds occurs during the heating step, and the removal of more of the one or more functionalizing compounds (e.g., removing the remainder of the one or more functionalizing compounds, removing the remainder of the heating step) occurs during the removing step (e.g., as described below). In some examples, the heating does not remove any of the one or more functionalizing compounds. In other embodiments, the solvent does not decompose (e.g., does not significantly and / or deleteriously decompose) the perovskite layer during heating.

[0050] In some embodiments, the removing step occurs and can be by any suitable method for removing some or all of the one or more functionalizing compounds, removing some or all of the one or more functionalizing compounds (e.g., removing acetate or propionate). In certain embodiments, removing some or all of the one or more functionalizing compounds occurs by intense pulsed light (IPL), by further heating (e.g., using a hot plate, an oven (e.g., a convection oven), or IPL) (e.g., heating includes heating at about 80°C to about 120°C (e.g., about 80°C, about 90°C, about 100°C, about 110°C, or about 120°C) for about 5 to about 20 minutes (e.g., about 5, about 8, about 10, about 12, about 15, or about 20 minutes), or both. In other embodiments, the solvent does not decompose (e.g., does not significantly and / or deleteriously decompose) the perovskite layer during removal.

[0051] In certain embodiments, the perovskite layer can be any suitable perovskite layer (e.g., a perovskite film). In other embodiments, the perovskite layer can be CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, CH3NH3SnX3, or Cs a (CH5NH3) b (CH3NH3) c PbI 3(1-y) Br 3y where X is a halogen (e.g., iodide, bromide, or chloride) that may be the same or different between or within each formula, a may be from about 0 to about 0.5, b may be from about 0 to about 0.8, c may be from about 0 to about 0.8, and y may be from about 0 to about 1. Other suitable perovskite layers (e.g., perovskite films) include those disclosed in U.S. Pat. No. 10,950,794, issued March 16, 2021, which is incorporated herein by reference in its entirety.

[0052] In some embodiments, the PSC is a pin-type device. In other embodiments, the PSC is a nip-type device. Examples of various layers, such as HTL or ETL, in these devices (and methods of making them) can be found, for example, in (a) Pitchaiya et al. (2020) "A review on the classification of organic / inorganic / carbonaceous hole transporting materials for perovskite solar cell application" Arab. J. Chem., Vol. 13, pp. 2526-2557 (incorporated herein in its entirety by reference) and (b) Foo et al. (2022) "Recent review on electron transport layers in perovskite solar cells" International Journal of Energy Research, 2022, pp. 1-11 (incorporated herein in its entirety by reference).

[0053] In other embodiments, the PSC is a flexible PSC. Examples of flexible PSCs and methods for making them can be found, for example, in (a) Tang et al. (2021) "Recent progress of flexible perovskite solar cells" Nano Today, Vol. 39, Article 101155 (incorporated herein in its entirety by reference) and (b) Di Giacomo (2016) "Progress, challenges and perspectives in flexible perovskite solar cells" Energy and Environmental Science, 2016, Vol. 9, pp. 3007-3035 (incorporated herein in its entirety by reference).

[0054] In certain embodiments, the perovskite layer is coupled to an anode (e.g., any suitable anode, such as ITO / glass or FTL / glass), a hole transport layer (HTL) (e.g., PTAA or NiO x In one embodiment, the cathode may be part of a structure that further includes one or more of a HTL, a SiO2 layer, a SiO2 layer, a SiO2 layer, or a cathode (e.g., any suitable cathode such as Fe, C, Ni, Pt, Ag, Al, or Cu).

[0055] In other embodiments, the perovskite layer may be part of a structure that further includes one or more of an anode (e.g., any suitable anode, such as ITO / glass or FTL / glass), an electron transport layer (ETL) (e.g., any suitable ETL, such as SnO2, TiO2, or ZnO), or a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu).

[0056] In some embodiments, the method further comprises adding a cathode. Any suitable method of adding a cathode can be used, including but not limited to screen printing, thermal evaporation, sputtering, or atomic layer deposition. In certain embodiments, the method of adding a cathode comprises thermal evaporation. The added cathode can be any suitable cathode, including but not limited to Fe, C, Ni, Pt, Ag, Al, or Cu. In other embodiments, the cathode is Ag, Al, or Cu.

[0057] In certain embodiments, the PSC has an open circuit voltage (Voc) of about 0.7 V to about 1.3 V or about 0.8 V to about 1.1 V (e.g., about 0.7, about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, or about 1.3 V).

[0058] In some embodiments, the PSC has a fill factor (FF) of about 35 to about 80% or about 39 to about 77% (e.g., about 35, about 40, about 45, about 50, about 55, about 56, about 57, about 58, about 59, about 60, about 61, about 62, about 63, about 64, about 65, about 70, about 75, or about 80%).

[0059] In certain embodiments, the PSC has a current density of about 10 to about 25 mA / cm 2 , or about 12 to about 24 mA / cm 2 (e.g., about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, or about 25 mA / cm 2 ) current density (J sc ).

[0060] In other embodiments, the PSC has a power conversion efficiency (PCE) of about 4 to about 20% or about 4 to about 15% (e.g., about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, or about 20%).

[0061] Some embodiments of the invention include a PSC made as disclosed herein (e.g., as disclosed above, in original claim 1, or as disclosed in the Examples). In other embodiments, the PSC is a flexible PSC.

[0062] Other embodiments of the invention include organic materials, metal oxides, TiO2, SnO2, ZnO, NiO (e.g., when the material is in the electron transport layer). x , Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 The present invention also includes a PSC (e.g., as disclosed herein) that includes a material selected from one or more of a BM, or a fullerene. In certain embodiments, the material can be functionalized according to any manner disclosed herein (e.g., as disclosed above, as disclosed in original claim 1, or as disclosed in the Examples). In some embodiments, the material includes SnO2, functionalized SnO2 (e.g., functionalized with acetate), or both. In other embodiments, the PSC is a flexible PSC.

[0063] Another embodiment of the invention is a photoresist-based thin-film transistor comprising: (a) an anode (e.g., any suitable anode, such as ITO / glass or FTL / glass); (b) a hole transport layer (HTL) (e.g., NiO x , PTAA, or PTAA / PFN); (c) a perovskite layer (e.g., any suitable perovskite such as one or more of CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, or CH3NH3SnX3, where X is a halogen (e.g., iodide, bromide, or chloride) that may be the same or different between or within each formula); (d) an electron transport layer (ETL) (e.g., an organic material, a metal oxide, TiO2, SnO2, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C 60 , C 70 , P.C. 61 B.M., P.C. 71 In another embodiment, the PSC comprises a PSC (e.g., as disclosed herein) comprising a material selected from a BM, or a fullerene, or a functionalized material thereof, or SnO2 or a functionalized SnO2 (e.g., functionalized with acetate), and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In another embodiment, the PSC is a flexible PSC.

[0064] Some embodiments of the invention include a photovoltaic device comprising: (a) an anode (e.g., any suitable anode, such as ITO / glass or FTL / glass); (b) an electron transport layer (ETL) (e.g., any suitable ETL, such as SnO2, TiO2, or ZnO); (c) a perovskite layer (e.g., any suitable perovskite, such as one or more of CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, or CH3NH3SnX3, where X is a halogen (e.g., iodide, bromide, or chloride) that may be the same or different between or within each formula); (d) a hole transport layer (HTL) (e.g., an organic material, a metal oxide, NiO x or CuO, or a functionalized material thereof, or NiO x or functionalized NiO (e.g., acetate-functionalized).x ), and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.

[0065] Another embodiment of the invention is a photoresist-based thin-film transistor comprising: (a) an anode (e.g., any suitable anode, such as ITO / glass or FTL / glass); (b) a hole transport layer (HTL) (e.g., NiO x , PTAA, or PTAA / PFN), (c) a perovskite layer (e.g., any suitable perovskite such as one or more of CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, or CH3NH3SnX3, where X is a halogen (e.g., iodide, bromide, or chloride) that may be the same or different between or within each formula), (d) an electron transport layer (ETL) (prepared as disclosed herein, such as in original claim 1 or by any of the methods disclosed herein), and (e) a cathode (e.g., any suitable cathode such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.

[0066] Some embodiments of the invention include a PSC (e.g., as disclosed herein) that includes: (a) an anode (e.g., any suitable anode, such as ITO / glass or FTL / glass); (b) an electron transport layer (ETL) (e.g., any suitable ETL, such as SnO2, TiO2, or ZnO); (c) a perovskite layer (e.g., any suitable perovskite, such as one or more of CH3NH3PbX3, CH3NH3PbI3, H2NCHNH2PbX3, or CH3NH3SnX3, where X is a halogen (e.g., iodide, bromide, or chloride) that can be the same or different between or within each formula); (d) a hole transport layer (HTL) (prepared as disclosed herein, such as in original claim 1 or by any of the methods disclosed herein); and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.

[0067] The subject matter of the present disclosure is further illustrated by the following specific, but non-limiting examples. The following examples may include compilations of data representative of data collected at various times during the course of development and experimentation related to the present invention. EXAMPLES

[0068] Example Set A - Direct Deposition of Non-Aqueous SnO2 Dispersions by Blade Coating on Perovskite for Scalable Fabrication of Perovskite Solar Cells The device architecture of a perovskite solar cell (PSC) may include a perovskite absorber sandwiched between n-type and p-type semiconductors in either a planar nip or inverted pin structure. The n-type semiconductor serves as an electron transport layer (ETL) in extracting photogenerated electrons from the active perovskite material, transporting the electrons to the electrodes, and blocking hole transport during the conversion of light to electricity. It may therefore be desirable for the ETL material to have a suitable band gap and appropriate energy alignment with the perovskite, along with high electron mobility and conductivity.

[0069] Direct deposition of fully solution-processed SnO2 onto a perovskite absorber layer in a pin structure has not yet been reported. The absence of solution-processed SnO2 ETL in the pin structure may be due, in part, to solvent incompatibility between SnO2 and perovskites. The library of perovskite-compatible solvents is limited and typically excludes the highly polar solvents used to prepare SnO2 dispersions. This is further complicated when using scale-up coating techniques such as blade coating, where the evaporation kinetics result in prolonged exposure of the perovskite to the solvent. Thus, metal oxide dispersions that are more suitable for blade coating onto perovskites should be prepared using non-polar or less polar organic solvents.

[0070] In this example, we report the direct deposition of SnO2 thin films as ETL on perovskite in pin device structures by blade coating under ambient conditions. To enable direct deposition of SnO2 on perovskite, SnO2 nanoparticles synthesized using a sol-gel method were functionalized with acetic acid to obtain particles of tin oxide acetate (SnO2-A). Functionalization of SnO2 with acetate allowed the formation of a stable colloidal dispersion of SnO2-A in absolute ethanol, which was directly deposited on the perovskite film. The SnO2-based devices exhibited an average PCE of 12.27% and a champion PCE of 14.1%. The devices maintained an average initial PCE of 95.8% after 40 days.

[0071] Results and Discussion Perovskite-compatible SnO2 inks were prepared by functionalization of SnO2 nanoparticles to improve their dispersibility in non-aqueous solvents (Figures 1a-c). Aqueous SnO2 was prepared from tin chloride and sodium hydroxide following established literature procedures (Fuller et al., The catalytic oxidation of carbon monoxide on tin(IV) oxide. J. Catal. 1973, 29, 441-450; McManus et al., Highly soluble ligand stabilized tin oxide nanocrystals: gel formation and thin film production. Cryst. Growth Des. 2014, 14, 4819-4826). The aqueous SnO2 nanoparticle particles were then reacted with acetic acid to yield acetate-functionalized SnO2 (SnO2-A) through ligand exchange. The X-ray diffraction (XRD) patterns of hydrous SnO2 and SnO2-A (Fig. 1d) both show peaks at 26°, 34°, 52°, and 65°, which are assigned to the (110), (101), (211), and (112) planes of the rutile crystal structure of SnO2. The similarity of the XRD patterns indicates that the ligand exchange reaction is simply a surface modification of hydrous SnO2, with no observable change in the crystal structure. The coordination of acetate ligands to the metal oxide surface was confirmed by Fourier transform infrared (FT-IR) spectroscopy. The possible bonding modes of the carboxylate ligands include monodentate, bidentate, or bridging (Deacon et al., Relationships between the carbon-oxygen stretching frequencies of carboxylato complexes and the type of carboxylate coordination. Coord. Chem. Rev. 1980, 33, 227-250). The FT-IR spectra of hydrous SnO2 and SnO2-A (Fig. 1e) show the 650 cm -1 The spectrum of hydrous SnO2 shows a common feature at 3300 cm associated with the OH stretching of adsorbed water on the surface of hydrous SnO2. -1Broadband and 1640cm -1 The OH stretching band is reduced in SnO2-A, indicating that the hydroxyl groups on the surface of hydrous SnO2 are replaced. The acetate coordination in SnO2-A shows a sharp band at 1715 cm associated with the C=O stretching and acetate scissoring vibrations of the acetate ligand. -1 and 1380cm -1 This is supported by the presence of a band in

[0072] In contrast to aqueous SnO2, SnO2-A nanoparticles are easily dispersed in protic organic solvents such as ethanol and isopropanol. Without being bound by theory, the enhanced dispersibility of SnO2-A particles in protic organic solvents may be due to the formation of hydrogen bond networks between surface-bound acetate, excess acetic acid, and ethanol. In some instances, long-chain carboxylates may more effectively prevent aggregation of SnO2 nanoparticles, allowing the formation of stable colloidal dispersions of SnO2 in perovskite-compatible nonpolar organic solvents, while in other instances, residual long-chain ligands in the ETL may hinder the charge transfer process and reduce the overall efficiency of the PSC.

[0073] We chose to functionalize SnO2 with short-chain carboxylic acids, even though this limits the choice of solvent for the ink formulation to absolute ethanol. To study the affinity of the perovskite with the dispersion medium, a dispersion of SnO2-A in absolute ethanol was directly deposited on top of a perovskite layer of CH3NH3PbI3 (MA = methylammonium) via blade coating. The XRD patterns of the perovskite before and after deposition of SnO2 on the perovskite are shown in Figure 2a. The XRD pattern of the perovskite before deposition shows a single prominent peak at 14.1°, as expected for CH3NH3PbI3. The XRD pattern does not change after deposition of SnO2, indicating that the perovskite layer remains intact. If moisture-mediated decomposition occurs, an additional peak is observed at 12.7° due to the formation of PbI2. The XRD patterns confirm that a dispersion of SnO2-A in absolute ethanol can be directly dispensed onto the perovskite and deposited without detectable degradation of the perovskite surface.

[0074] The kinetics of charge carrier activity of solution-phase deposited SnO2 layers on perovskite was studied using photoluminescence (PL) and time-resolved PL (TRPL) spectroscopy. Steady-state PL spectra of perovskite and perovskite / SnO2 on glass substrate are shown in Figure 2b. The photoluminescence of perovskite is strongly quenched in the presence of SnO2-A, indicating a significant decrease in charge carrier density, which is consistent with efficient charge transfer from the perovskite layer to the ETL. TRPL measurements of perovskite before and after deposition of SnO2-A on the perovskite support the results of the PL analysis. In Figure 2c, TRPL spectra obtained from the glass side of glass / perovskite and glass / perovskite / SnO2-A samples show a significant decrease in photoluminescence lifetime after deposition of SnO2-A. Such a decrease in photoluminescence lifetime confirms effective charge extraction by the ETL from the perovskite absorber layer.

[0075] Based on the promising XRD, PL, and TRPL results, we fabricated PSCs with pin architecture using SnO2-A as the ETL. A series of planar PSCs were fabricated on indium tin oxide (ITO)-coated glass with a polytriarylamine (PTAA) hole transport layer (HTL) and a poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-ortho-2,7-(9,9-dioctylfluorene)] (PFN) interfacial layer. The overall device architecture is ITO / PTAA / PFN / CH3NH3PbI3 / SnO2-A / Ag. A schematic diagram of the device architecture is shown in Figure 3a, which highlights the solution-phase blade coating of SnO2-A as the ETL on top of the perovskite. The PTAA, PFN, and CH3NH3PbI3 layers were also deposited using blade coating in ambient conditions. The SnO2-A layer was annealed at 100°C for 10 min to remove the solvent, and finally, silver was thermally evaporated as the top contact layer. The annealing process was optimal at 100°C and 10 min.

[0076] The deposition of SnO2-A on the fully converted perovskite gives rise to a uniform layer with a reflective surface. Figure 3b shows a cross-sectional scanning electron microscope (SEM) image of the proposed pin device structure. Each of the individual layers can be clearly identified. Notably, there is no visible physical deformation of the perovskite layer due to the deposition of the SnO2-A ink directly on the perovskite. In addition, the SnO2-A layer is compact, uniform, and pinhole-free. The optimized thickness of the SnO2 ETL was measured to be 36.7 ± 3.4 nm.

[0077] The JV characteristics of the fabricated cells were measured under one solar condition (AM1.5G, 100 mW / cm 2 ) and the power conversion efficiency (PCE), fill factor (FF), and short circuit current density (J sc ), and open circuit voltage (V oc Their corresponding photovoltaic parameters, including the temperature, humidity, and photovoltaic power generation, were recorded. sc is 22.61mA / cm 2 , Voc The device exhibited a PCE of 14.1%, with a gate capacitance of 1.023 V and a gate offset of 61% (Fig. 4). 60 A standard device of J / BCP / Ag (BCP = bathocuproine) was fabricated and evaluated under the same conditions. sc is 18.88mA / cm 2 , V oc The V = 1.024 and FF = 76.76%, yielding a PCE of 15.11% (data not shown). Both devices have very similar V oc values, indicating that SnO2-A is effective for charge collection. However, the SnO2-A device has a lower FF compared to the control device, which may suggest charge recombination at the interface or a larger ETL thickness. Interestingly, J sc The values ​​are higher for the SnO2-A device, which may be an artifact of the perovskite layer thickness.

[0078] To understand the stability of the fabricated devices, sample devices were stored in a nitrogen flow box after the initial JV measurements were recorded. The devices were stored without encapsulation and after 40 days, the JV characteristics were re-evaluated. Figure 5 shows the device performance statistics of the stability test. After 40 days, 95.8% of the average initial efficiency was retained. The efficiency loss was mainly due to the JV loss, which decreased by an average of 15.59%. sc Interestingly, the average V oc and FF values ​​increased by 4.85% and 8.42%, respectively, after storage.

[0079] conclusion In summary, solution-phase deposition of a non-aqueous dispersion of SnO2 nanoparticles onto CH3NH3PbI3 perovskite by blade coating technique was demonstrated in a pin device architecture. Acetate-functionalized nanoparticles, SnO2-A, were synthesized using an aqueous reaction route that allowed for the formulation of a stable dispersion in absolute ethanol. After ink deposition on CH3NH3PbI3, no PbI2 peaks were observed in the XRD spectrum, indicating no observable damage to the perovskite thin film. Photoluminescence results demonstrate that electrons are transported out of the perovskite layer, and cross-sectional SEM shows a smooth interface between the CH3NH3PbI3 and SnO2 films. Champion PSCs have an active area of ​​0.25 cm 2 The patient achieved a PCE of 14.1% and maintained 95.8% of this at 40 days.

[0080] Experimental Section Synthesis of hydrous SnO2 Tin oxide nanoparticles were prepared using a sol-gel method by neutralizing an aqueous tin chloride solution with sodium hydroxide (McManus et al.,Highly soluble ligand stabilized tin oxide nanocrystals: gel formation and thin film production. Cryst. Growth Des. 2014, 14, 4819-4826). In general, a 0.5 M aqueous solution of SnCl4 was prepared by adding anhydrous SnCl4 dropwise into deionized (DI) water. A freshly prepared 5 M NaOH solution in DI water was added dropwise to a vigorously stirred aqueous solution of SnCl4 until the pH reached pH 6.5. The resulting white precipitate of hydrous SnO2 was aged for 12 h, collected by centrifugation, and washed repeatedly by dispersion in DI water / centrifuge until the aqueous layer was chloride-free. The washed hydrous SnO2 tin oxide particles were dried at room temperature for 24 h. XRD analysis confirmed the formation of SnO2. The actual mass of SnO2 present in the hydrous SnO2 was calculated to be 70% from TGA analysis.

[0081] Synthesis of SnO2-A and ink formulation Acetate-functionalized nanoparticles, SnO2-A, were prepared based on literature procedures (McManus et al., Highly soluble ligand stabilized tin oxide nanocrystals: gel formation and thin film production. Cryst. Growth Des. 2014, 14, 4819-4826). Generally, aqueous SnO2 and glacial acetic acid were mixed in a 1:1 mass:volume ratio. In a typical preparation, 4 grams of aqueous SnO2 were mixed with 4 mL of glacial acetic acid. The mixture was then heated at reflux for 1 hour in a closed vessel. The mixture initially formed a milky white colloidal dispersion that became colorless and transparent upon the formation of SnO2-A. If the reaction mixture did not become completely colorless and transparent, undissolved aqueous SnO2 could be removed via centrifuge. The percentage of SnO2 in the solution was determined from TGA analysis. An aliquot of the SnO2-A solution was dispersed in absolute ethanol to produce an ink containing 2% (m / v) SnO2 suitable for direct deposition onto perovskites by blade coating. For XRD and FT-IR analysis, the initial SnO2-A solution was transferred to an evaporating dish and the solvent was allowed to evaporate overnight. The solid product was dried in a vacuum oven at 100 °C for 2 h before analysis.

[0082] Device fabrication ITO precoated glass substrates were cut to 1 inch x 2 inch size and cleaned using Liquinox detergent solution, acetone, isopropanol, and nitrogen flush. After treating the cleaned glass substrate with UV-ozone for 15 minutes, PTAA, PFN, CH3NH3PbI3, and SnO2-A were sequentially deposited by blade coating in ambient environment. PTAA solution was prepared by dissolving 8 mg of PTAA in 1 ml of toluene. An aliquot of 12 μL of the PTAA solution was used for blade coating with a coating speed of 10 mm / s and a blade gap of 100 μm, followed by heating at 100 °C for 10 minutes and then cooling to room temperature. Then, 12 μL of a 0.4 mg / mL PFN solution in methanol was blade coated onto the PTAA layer with a coating speed of 7.5 mm / s and a blade gap of 100 μm. The perovskite precursor solution was prepared by dissolving methylammonium iodide and PbI2 in a mixture of DMF:DMSO:NMP with a volume ratio of 0.91:0.07:0.02 to obtain a 1.2 M solution (Ouyang et al., Toward scalable perovskite solar modules using blade coating and rapid thermal processing. ACS Appl. Energy Mater. 2020, 3, 3714-3720). A 20 μL aliquot of the perovskite precursor solution was deposited at a coating speed of 7.5 mm / s by blade coating with a blade gap of 150 μm. Immediately after deposition of the perovskite precursor solution, the wet film was pre-dried using a N2 air knife and subsequently hotplate annealed at 140 °C for 2 min. Finally, 20 μL of SnO2-A dispersion in absolute ethanol was deposited on the perovskite with a blade gap height of 100 μm and a coating speed of 7.5 mm / s, followed by annealing at 100 °C for 10 min. The fabrication of PSCs with a device architecture of glass-ITO / PTAA / PFN / CH3NH3PbI3 / SnO2-A / Ag was completed by depositing 100 nm of silver on the ETL of SnO2-A using thermal evaporation. After silver deposition, the devices were fabricated into a 300 nm thick PSC with an active area of ​​0.25 cm2.2 The scribed area was mechanically scribed.

[0083] physical method Powder X-ray diffraction (PXRD) patterns were measured using a Bruker D8 Discover X-ray diffractometer. Infrared spectra were collected using a Thermo Nicolet Avatar 360 FT-IR equipped with a Smart iTR. Cross-sectional SEM images were recorded using a JEOL7000 field emission scanning electron microscope (SEM). PL analysis was performed using a Renishaw Via Raman microscope equipped with a CCD detector and a 632 nm He-Ne laser source. Current density-voltage (JV) characteristics of the devices were measured under one sun conditions (AM1.5G, 100 mW / cm 2 The measurements were performed using a class AAA solar simulator with a xenon arc lamp of 1000 mA. Prior to device measurements, the solar simulator was calibrated using an NREL-certified Si reference cell. The devices were tested from 1.2 to 0 V with a scan rate of 100 mV / s and a step size of 10 mV.

[0084] Example Set B - NiO for the Deposition of Hole Transport Layer in Perovskite Solar Cells (PSC) x Solvation of A series of nickel oxides (NiO) in perovskite antisolvent chlorobenzene (CB) containing 15% ethanol x A ) ink was prepared for the fabrication of pin perovskite solar cells by blade coating. The ink contained NiO xTriethylamine (Et3N) and an alkyl xanthate salt were included as ligands to disperse particle aggregates and stabilize the suspension. A total of four inks were evaluated: 0X (Et3N without alkyl xanthate), 4X (Et3N + potassium n-butyl xanthate), 12X (Et3N + potassium n-dodecyl xanthate), and 18X (Et3N + potassium n-octadecyl xanthate). The inks were characterized by UV-Visible and FT-IR spectroscopy, and the resulting films were analyzed by thermogravimetry and scanning electron microscopy. The device prepared using the 0X ink had a peak power conversion efficiency (PCE) of 14.47% (at 0.25 cm). 2 ) and 9.96% (1cm 2 ) The 0X device showed no significant loss of PCE after 100 days in the nitrogen flow box. Devices prepared with inks containing alkyl xanthate ligands had lower PCE that decreased with decreasing chain length (18X > 12X > 4X).

[0085] In this example, we demonstrate the synthesis of soluble NiO for solution-phase deposition of inorganic HTL for use in scalable PSCs. x We report the development of particles. Some PSC devices contain a perovskite active layer between an electron transport layer (ETL) and a hole transport layer (HTL) on an indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) substrate with a metal (Ag or Au) top electrode. The device architecture can be nip or pin, depending on the relative order of the ETL (n), perovskite (i), and HTL (p). The HTL and ETL layers can have a role in improving the photovoltaic performance of the PSC through modulation of charge carrier recombination and charge extraction capabilities.

[0086] In some aspects of this embodiment, NiO is produced with reduced presence of residual organic ligands. X To obtain films, ligands with variable alkyl chain lengths were used to obtain chlorobenzene (CB)-philic NiO xWe explore the development of nanoparticles. - A series of inks with xanthates (Cu, Cd, Cl, Cl) and triethylamine (Et3N) have been prepared (Figure 6). Xanthates were chosen as an alternative to carboxylates due to their exceptionally high degree of instability, while still being structurally equivalent to carboxylates and easier to prepare from low-cost materials. The Et3N additive was included because it was found to improve the stability of the dispersion. One objective of this example was to identify potential alkyl chain lengths to obtain CB-stable inks for the fabrication of functional PSCs by blade coating.

[0087] Experimental Section Materials and Methods NiO x The particles were synthesized by a known solvothermal method (Beach et al, Chem. Phys. 2009, 115, 371-377). Briefly, nickel acetylacetonate (Ni(acac)2) was dissolved in methyl ethyl ketone (MEK) to form a 0.1 M solution. The resulting solution was sparged with N2 gas for 30 min and then sealed in a Teflon-lined Parr reactor. The reactor was heated at 225 °C for 16-18 h. The reactor was cooled to room temperature and the resulting product was isolated from the solution by centrifugation for 15 min. Crude NiO xThe product was washed by repeated suspension / isolation with MEK and isopropanol (IPA). Potassium xanthate salts were prepared from potassium hydroxide, carbon disulfide, and the appropriate alcohol using reported methods. Xanthates with 4- and 12-carbon chains were isolated as yellow solids as described by Carta (Carta et al., J. Med. Chem. 2013, 56, 4691-4700). 18-carbon chain xanthates were prepared as white solids as reported by Sawant (Sawant et al., Langmuir 2001, 17, 2913-2917). The sodium carbonate salts were prepared as flaky white solids from sodium phenoxide, carbon dioxide, and the appropriate alcohol according to the method reported by Ichiro (Ichiro et al., B. Chem. Soc. Jpn. 1976, 49, 2775-2779).

[0088] physical method NiO x Powder X-ray diffraction (PXRD) patterns of the powders were measured using a Bruker Discovery D8 high-resolution X-ray diffractometer with Cu Kα radiation (1.54 Å, 40 KV, step speed 0.7 sec / step, 25°-85°). Films were deposited using a Zehntner ZAA2300 automatic film applicator and a ZUA2000 universal applicator equipped with an air knife. x The surface morphology of the powders and films was characterized using a top-view scanning electron microscope (SEM, Thermo-Fisher Scientific Apreo C LoVac FESEM). The thickness and roughness of the films were measured using a Veeco Dektak8M surface profilometer. Absorption spectra of NiO x was measured using an ultraviolet-visible spectrophotometer (Agilent 8453). xThe stability and particle size of the inks were characterized by performing Zeta potential measurements (Brookhaven Instrument Corporation 90Plus particle size analyzer). Infrared spectra of the organics and inks were collected using a Thermo Nicolet Avatar360 FT-IR with Smart iTR. Thermal decomposition of the xanthates and associated inks was identified by thermogravimetric analysis (TGA, differential scanning calorimeter Q20 30 °C-800 °C, 20 °C / min). Current density-voltage (JV) characteristics of the devices were characterized under one sun conditions (AM1.5G, 100 mW / cm). 2 The measurements were performed using a class AAA solar simulator with a xenon arc lamp of 1000 mA. Prior to device measurements, the solar simulator was calibrated using an NREL-certified Si reference cell. The devices were tested from 1.2 to 0 V with a scan rate of 100 mV / s and a step size of 10 mV.

[0089] Device fabrication Devices were fabricated with the following pin architecture: glass / ITO / NiO x / PFN / MAPbI3 / C 60 / BCP / Ag, where PFN and BCP are poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-ortho-2,7-(9,9-dioctylfluorene)] and bathocuproine, respectively. The ITO coated glass was cut into 1" x 2" substrates and cleaned with a N2 flash, followed by UV-O3 treatment for 15 minutes and a second N2 flash. No further steps were taken to clean the ITO substrates. The cleaned ITO substrates were then coated with NiO by blade coating. x It was immediately used for the sequential deposition of NiO, PFN, and MAPbI. x The ink was prepared by dissolving NiO in 200 μL of a 3:1 (v / v) EtN / EtOH mixture. x Particles (20 mg) were prepared by sonication in a closed vial for 60 min at 65° C. The resulting suspension was diluted with 700 μL of CB and 100 μL of EtOH to obtain NiO xA 20 mg / mL solution was prepared. NiO containing xanthate ligands x For the inks, 0.125 equivalents of ligand were added to the CB in the dilution step. After dilution, the suspensions were heated at 65 °C and sonicated. During this step, the inks containing the xanthate ligand underwent a color change, as shown in Figure 6. Prior to blade coating, the hot ink suspension was filtered through 0.2 μm PTFE. x Ink 40μL -2 At a speed of 5 mm / sec -1 The films were deposited by blade coating using an optimized blade gap of 225 μm at 400 rpm and subsequently annealed on a hotplate at 300 °C for 20 min. Then, the films were heated at a speed of 7.5 mm s -1 A layer of PFN (4 mg / mL in methanol) was deposited by blade coating with a blade gap of 100 μm at 37°C. The perovskite ink was prepared by dissolving PbI2 and MAI in dimethylsulfoxide (DMSO, 7%), N-methyl-2-pyrrolidone (NMP, 2%), and dimethylformamide (DMF, 91%) to make a 1.2 M solution by gentle stirring. The perovskite was deposited by blade coating with a blade gap of 100 μm at a speed of 7.5 mm s at room temperature. -1 After perovskite deposition, the film was dried using a N2 knife at 40 psi and then annealed at 140 °C for 2 min. 60 , BCP, and Ag were thermally evaporated, followed by 0.25 and 1 cm 2 This was accomplished by mechanically scribing the active area of ​​the cell.

[0090] Glass / ITO / SnO2 / MAPbI3 / NiO x The initial nip device with Au / Ag architecture was prepared by mixing 20 µL of 3% (wt%) commercial SnO2 nanoparticles in -2 The optimized SnO2 film was fabricated using the ETL as the ETL. -1The layer was deposited using blade coating at 1000 .mu.m with a blade gap of 100 .mu.m, followed by annealing at 150.degree. C. for 1 hour. All other layers were deposited in the same manner as above.

[0091] Results and Discussion Ink formulation and property evaluation A series of NiO that can be suspended in chlorobenzene (CB) as inks for the preparation of hole transport layers in perovskite photovoltaics x Nanoparticles have been prepared. x The particles were treated with alkyl xanthate (ROCS2 - The xanthate was first coupled with the Lewis base triethylamine (Et3N) to form a xanthate ligand (Figure 6). The alky substituents on the xanthate were varied to evaluate the effect of the carbon chain length on the ink properties and device performance. x Particles are identified based on the length of the alkyl chain as follows: 0X (no xanthate), 4X (n-butyl xanthate), 12X (n-dodecyl xanthate), 18X (n-octadecyl xanthate).

[0092] The first NiO x The particles were prepared by solvothermal synthesis as described by Beach (Beach et al., Mater. Chem. Phys. 2009, 115, 371-377). The identity and purity of the synthesized nanoparticles were confirmed by powder X-ray diffraction (PXRD) studies, which showed the expected peaks at 36.8° (111), 42.8° (200), 62.3° (220), 74.7° (311), and 78.8° (222). From the PXRD, the crystal size was estimated to be about 8 nm based on the Scherrer formula. These small particles tend to aggregate in the solid phase and form large aggregates, as shown in the SEM image in Figure 7a. The initially prepared NiO xThe nanoparticles were dispersed in a 3:1 (v / v) Et3N / EtOH solution and sonicated at 65 °C for 1 h. Et3N, a Lewis base with high donor number and entropic alkyl groups, was added as a weakly coordinating ligand to help break up aggregates and prevent reagglomeration by altering the energy and steric forces of the particle surface. After sonication, the dispersion was diluted with a 7:1 (v / v) CB / EtOH solution supplemented with xanthates, if used. The resulting ink suspension was then filtered through a 0.2 μm PTFE filter, resulting in a clear suspension (Figure 6). SEM images of films prepared using 0X ink show the NiO ionization by Et3N. x It showed the formation of a uniform film, confirming the breakdown of aggregates into smaller nanoparticles (Figure 7b). Dynamic light scattering on the sonicated 0X ink found the particle size to be 8.3 ± 2.1 nm, which is consistent with the PXRD size estimates.

[0093] NiO x To quantify the effect of Et3N on the dispersion stability of the particles, the ζ-potential was measured for the 0X solution. The ζ-potential measures the potential difference between the dispersed particles and the medium in which the suspension is stable, generally with a value of ±30 mV. The ζ-potential may depend on the composition of the particles and their chemical environment. Before the addition of Et3N, the initially prepared NiO x The ζ-potential of the particles was 6.19 ± 3.0 mV, consistent with their observed aggregation. Addition of 15% Et3N to produce OX particles increased the ζ-potential to 27.29 ± 3.9 mV. The results show that Et3N can effectively disperse NiO in CB even in the absence of additional alkyl xanthate ligands. x It has been shown that the amount of glycerol in the suspension is sufficient to stabilize the suspension.

[0094] The addition of alkyl xanthates to the 0X ink resulted in the formation of NiO in xanthates, as observed by UV-visible spectroscopy. x A ligand exchange process occurs with coordination to the particles. The 0X ink has a primary exciton peak centered at 300 nm, and the ink is visually light brown in CB.x When added to the particles, it produces a dark brown suspension after heating and filtering (Figure 6). A comparison of the UV-Vis spectra of alkyl xanthates and their corresponding inks shows that the color change is due to the alkyl xanthates' NiO x The UV-visible spectra of 12X alkyl xanthate salts in CB show that the 12X alkyl xanthate salts are related to the coordination of the NiO x The inks show an interligand band at 380 nm that shifts to 420 nm upon addition of (Figure 8a). In addition, there is a new band at 480 nm in the ink associated with ligand / metal charge transfer from the xanthate to nickel. Similar bands are observed at 476 nm and 414 nm in the molecular nickel xanthate complex. The UV-visible spectra of the 4X and 18X xanthate salts and their inks show similar features (data not shown).

[0095] NiO x The coordination of alkylxanthate ligands to the particles was further confirmed by FT-IR spectroscopy. The spectrum of 12X alkylxanthate was similar to that of NiO x When added, the ink has a temperature of 1030 cm -1 Shift to 1070cm -1 C=S stretching at 1120cm -1 ~1230cm -1 The COC stretching in (see Figure 8b) is shown, along with the coordination of the related alkyl carbonates (ROCO2 - Attempts to prepare a series of inks based on 0X NiO x Failure was due to decomposition of the alkyl carbonate upon addition to the suspension (data not shown).

[0096] Thermogravimetric analysis (TGA) was performed on the alkyl xanthate ligands and their corresponding inks to determine their stability under annealing conditions. x Residual long-chain compounds in the layers have been shown to reduce the PCE of PSCs, so ligands that decompose during annealing may offer an advantage. xPrevious TGA studies on particles yielded an annealing temperature of 300°C (Beach et al., Mater. Chem. Phys. 2009, 115, 371-377). The TGA of the 12X salt, as a powder, shows an initial slight mass loss due to dehydration, followed by a rapid and substantial mass loss associated with xanthate decomposition at 210-315°C (Figure 9a). The TGA of a film prepared from the 12X ink shows similar decomposition characteristics at 135-350°C (Figure 9a). Results for the 4X and 18X ligands and inks are similar with xanthate decomposition occurring at 210-320°C (data not shown). Notably, all xanthates are NiO x The particle decomposes at annealing temperatures below 300 °C, and under the present conditions, xanthate is converted to NiO x It is shown to be completely removed from the film.

[0097] Film Deposition 0X~18X ink is applied by blade coating with a blade gap of 225μm at a speed of 5mm / sec. -1 The 0X film was deposited as a thin film on ITO glass at 200° C. The film was annealed at 300° C. for 20 min. Using these parameters, a film thickness of approximately 40 nm was reproducibly obtained as determined with a Dektak profilometer. The roughness of the 0X film is measured by Dektak to be 5.9 nm. SEM imaging of the 0X film shows a dense film with no visible pinholes (FIG. 9b). The denseness of the film is due to the presence of volatile Et3N in the ink. Et3N dissolves NiO in the ink. x Once the ink is deposited, evaporation of the Et3N results in the NiO x This allows the particles to pack tightly within the film.

[0098] For inks containing xanthate ligands, the film quality depends on the length of the carbon chain. SEM imaging of the 18X film shows uniform coverage with the presence of some pinholes (Figure 9d). The surface roughness is found to be about 6.5 nm. Imaging of the 12X film shows the film with significant pinholes, and the presence of aggregated particles (Figure 9c). These defects result in a roughness of 12.9 nm. The 4X ink was unable to produce a uniform film, with only a small amount of aggregates observed on the surface (data not shown). Without being bound by theory, it is believed that the uniform coverage of the long chain xanthate ligands (18X) induces alignment of the hydrophobic alkyl chains, which results in the NiO x This may be due to the strong dispersion forces, which allow for tighter packing of the particles. Removal of the xanthate ligands during annealing results in the formation of some pinholes as the xanthates decompose into gaseous products. Without wishing to be bound by theory, it has been suggested that the short-chain xanthate ligands (4X) are unable to induce film formation and the NiO on the surface is not stable. x It is assumed that this results in a random distribution of particles, which degrades film quality upon annealing, resulting in significant aggregation. Films formed with the intermediate length xanthate (12X) show both pinholes and significant particle aggregation, but are still able to form films.

[0099] Device performance To evaluate the effect of xanthate ligands on PSC performance, a glass / ITO / NiO x / PFN / MAPbI3 / C 60 A series of devices with NiO / BCP / Ag architecture were x , PFN, and MAPbI3 blade coatings, and C 60 The cells were constructed by thermal evaporation of ZnO, BCP, and Ag. The cells had an active area of ​​0.25 cm. 2The 0X devices were mechanically scribed into a 100 nm diameter and tested under one sun condition. PFN was incorporated to improve surface wetting of the perovskite deposition using known blade coating parameters. Figure 10 shows the distribution of device performance parameters across multiple samples of different ligand conditions investigated. The device performance results show that 0X is clearly superior to xanthate coated particles. However, for xanthate containing devices, the performance decreases as the xanthate chain length decreases. The bright and dark current-voltage (JV) curves of the champion devices and their corresponding photovoltaic parameters are summarized in Table B1. The highest 0X device exhibits a PCE of 14.47% and a current density (J sc ) 19.23mA / cm 2 , open circuit voltage (V oc ) 1049.32 mV, and fill factor (FF) 71.72%. Table B1. Champion Device Photovoltaic Parameters [Table 1]

[0100] J sc The relative value of NiO observed in the SEM image x This is consistent with the difference in film quality, which may affect the quality of the perovskite layer. sc The values ​​are highest for OX and decrease with decreasing chain length for films containing xanthate ligands. This is consistent with the increase in pinhole size and density in the HTL. sc This is consistent with previous studies showing that a decrease in V oc can depend on the total surface coverage, which is approximately constant when there is at least 80% surface coverage. oc The V falls from 0X to 18X to 12X, consistent with the decrease in surface coverage within this series, and then drops significantly in the 4X, which was implemented as a photoresistor, due to a decrease in film quality. Overall, the high V oc and J scindicates a high level of uniformity in the HTL and subsequent perovskite deposition. sc The variations in are due to slight variations in the perovskite itself, but do not have an overall effect on the observed trends.

[0101] Further confirming the significant effect of film quality, FF shows a drop of almost 20% from the 0X to 18X devices. FF is the shunt (R sh ) and series (R s ) resistance. The series resistance in these two films is similar (0X: 8.0 Ω cm) despite the inclusion of long-chain xanthate ligands in the 18X ink. 2 18X: 6.9Ωcm 2 ). This is due to the removal of xanthate ligands during the annealing step. However, the shunt resistance of the 0X film is more than twice that of the 18X film (0X: 728 Ω cm 2 18X: 316Ωcm 2 ), resulting in improved FF in the 0X devices. The lower shunt resistance in the 18X devices is consistent with the increased pinhole presence noted above.

[0102] Next, 0X and 18X are 1 cm 2 The JV curves are shown in Figure 11 and the data are summarized in Table B1. 2 For this device, 0X and 18X have similar V oc , F.F., R. s , and R sh However, between the 18X and 0X samples, J sc Approximately 4mA / cm 2 This difference results in a larger PCE for the 0X device. sc is 0.25 cm 2 This was also observed in the 0.25 cm device and can be attributed to pinholes, which are more prominent in the 18X film. 2 and 1 cm 2The comparison of 0X performance in cells is due to the presence of more pinholes over a larger area. sc and R sh The results show a 4.9 ± 0.3% decrease in PCE due to a decrease in

[0103] The long-term stability of the 0X and 18X devices was evaluated after 100 days of storage in a nitrogen flow box exposed to laboratory lighting. The device performance is summarized in Table B2. The 18X device sc , R sh , and a general degradation with a decrease in FF, resulting in a decrease in PCE after 100 days. The 0X devices show better stability. V oc and FF are decreasing, but J sc and R sh There is also an unexpected increase in the PCE, which does not result in a statistical change in PCE. Without being bound by theory, this increase may be due to the removal of more Et3N from the device interface, which has a vapor pressure of 7.2 kPa at 20 °C and will evaporate further as the device ages. Without being bound by theory, the increased stability of the 0X devices compared to the 18X devices may be due to the NiO x The quality of the films and the resulting perovskite can be attributed to fewer trap states that lead to film degradation. Table B2. 0.25 cm before and after 100 days of storage in a nitrogen flow box 2 Photovoltaic parameters of the device [Table 2]

[0104] Considering the performance of pin devices using 0X ink, the construction of nip devices is glass / ITO / SnO2 / MAPbI3 / NiO x The ETL, HTL and perovskite layers were deposited by blade coating using the parameters described in the experimental section. xUpon deposition, the appearance of the stack changed from a black mirror finish to a metallic blue color while retaining its reflective properties (Figures 12b and 12c). However, upon photovoltaic testing, no functional devices were found. MAPbI3-NiO by PXRD x Evaluation of the interface shows the appearance of a peak at 9.5° (Figure 12d) upon deposition of the 0X ink onto the perovskite. The same peak is observed when the ink solvent mixture (CB, EtOH, Et3N) is deposited onto the perovskite (data not shown). This suggests the formation of an Et3N adduct peak with the perovskite similar to that observed with DMSO. Notably, no peak is observed at 12.7°, indicating that MAPbI3 does not decompose to PbI2.

[0105] conclusion Perovskite in mixtures containing EtOH with Et3N (0X) or Et3N / alkyl xanthates (4X, 12X, 18X) x A series of ink formulations have been developed that successfully suspend nanoparticles. The carbon chain length of the alkyl xanthate was varied to investigate its effect on the ink performance. Hydrophobic chelating ligands were used to suspend NiO nanoparticles for the fabrication of PSCs. x Although EtN has previously been used to make NiO soluble, we have found that EtN alone can x We found that sonication was sufficient to stabilize the nanoparticles in solution and disperse the aggregates upon sonication. In fact, the 0X ink had a champion PCE of 14.47% (0.25 cm 2 ) and 9.96% (1cm 2 ) yielded the best film quality and device performance. The 0X cells were stable for 100 days in a nitrogen flow box with no significant change in PCE. For PSCs containing alkylxanthate ligands, the best film quality and device performance was obtained at 18X. Without being bound by theory, this is believed to be due to the dispersion interactions of the long carbon chains and the decomposition of the alkylxanthates during thermal annealing, resulting in the formation of NiO on the surface. xHowever, the 18X ink led to more pinholes than the 0X ink, resulting in a decrease in PCE. The short-chain alkyl xanthates performed less well, as the 4X ink was unable to form a film. Overall, the results suggest that the perovskite antisolvent CB based on the volatile and weakly coordinating Et3N ligand is a promising candidate for the formation of NiO in the perovskite antisolvent CB. x A new formulation for preparing inks is provided that offers several advantages over non-volatile charged ligands with long carbon chains.

[0106] Example set C-NiO x and Cu-doped NiO x Nanoparticles A 5 M solution of Ni(NO3)2·6H2O was prepared by dissolving Ni(NO3)2·6H2O in 25 mL of deionized water. Under vigorous stirring, a 10 M solution of NaOH was added by dropwise addition until the pH was adjusted to 10. The resulting precipitated Ni(OH)2 was then collected by centrifugation and washed repeatedly with deionized water. After washing, the Ni(OH)2 was thoroughly dried at 80 °C. The dried Ni(OH)2 was then collected and annealed at 270 °C for 15 min to obtain NiO x was converted to Cu-doped particles prepared in the same manner with 5 mol% Cu(NO3)2·3H2O substitution in the original Ni(NO3)2·6H2O solution.

[0107] Powder X-ray diffraction shows that upon addition of copper, cubic NiO x The results confirm the retention of structure (Figure 13). A slight loss of signal intensity is observed indicating a low level of crystallinity in the copper doped particles. From the Scherrer equation, the crystalline domain in the copper doped particles is found to be 6.9 nm and in the undoped particles 11.2 nm. The peak at 29° is associated with nitrate and could be successfully removed by further washing. The composition was confirmed by X-ray fluorescence to be Cu 5.6 ± 1.3%.

[0108] Doped and undoped nanoparticles were suspended in a 2:1 HO:isopropyl alcohol solution by brief sonication, then filtered by centrifuge for 2 h, followed by filtration through a 0.2 μm nylon filter. The resulting suspension was found to be stable for up to 3 days by dynamic light scattering (FIG. 14). Using fresh ink films deposited by roll-to-roll coating and intense pulsed light (IPL) annealing, 0.25 cm nanoparticles were obtained. 2 For the device, 8.85% NiO and 11.15% Ni 0.94 Cu .06 O x The peak device of PET / ITO / NiO was obtained (Table C1, Figure 15). x / MAPbI3 / C 60 A completed device constructed using the / BCP / Ag architecture. Perovskite films were deposited by blade coating using 2-methoxyethanol:ACN ink and annealed using IPL. Table C1. Cell performance parameters and IPL conditions [Table 3]

[0109] Example Set D - Yttrium-doped SnO2 as an efficient barrier layer in inverted flexible perovskite solar cells (f-PSCs) In this example, we investigated the direct deposition of tin(IV) oxide as an electron transport layer on top of perovskite for high performance f-PSCs. We synthesized SnO2 nanoparticles using a sol-gel method and functionalized them with acetate through ligand exchange that allowed them to be dispersed in absolute ethanol. In addition, we investigated in situ yttrium doping of SnO2 during synthesis to improve its performance as an ETL. Non-aqueous dispersions of pristine SnO2 and yttrium-doped SnO2 were directly deposited on perovskite by blade coating followed by air knife processing. There was no detectable damage to the underlying perovskite layer as evidenced by X-ray diffraction and scanning electron microscopy. Photoluminescence spectroscopy and device performance statistics confirm more electron extraction by yttrium-doped SnO2 compared to pristine SnO2. After yttrium doping, the champion power conversion efficiency increases from 14.40% to over 18%, which is unprecedented for an inverted device in a flexible ITO-PET substrate using SnO2 as the ETL. This example demonstrates that scalable direct deposition of fully solution-processed metal oxide charge transfer layers on perovskite should achieve highly efficient large-area flexible perovskite solar cells.

[0110] Perovskite solar cell (PSC) device architectures may include a thin perovskite layer sandwiched between two charge transport layers, which can be classified as nip or pin, where n represents the electron transport layer (ETL) and p represents the hole transport layer (HTL). The ETL can play roles in the PSC, including extracting and transporting photogenerated electrons, and preventing electron-hole recombination as a hole blocking layer. Thus, the ETL material may have a suitable band gap and appropriate energy alignment with the perovskite, along with high electron mobility and conductivity.

[0111] In this example, we synthesized yttrium-doped SnO2 nanoparticles (Y:SnO2) by a sol-gel method, in part to improve the electronic properties of low-temperature processed SnO2. The Y:SnO2 nanoparticles were functionalized with acetic acid to obtain acetate-functionalized Y:SnO2 (Y:SnO2-A). Functionalization of Y:SnO2 with acetate allowed the formation of a stable colloidal dispersion of Y:SnO2-A in absolute ethanol, which was directly deposited on the perovskite film by blade coating. Y-doping modified the electronic properties of the ETL, leading to efficient extraction and transport of charge from beneath the perovskite layer. The champion power conversion efficiency (PCE) of Y:SnO2 devices on flexible PET substrates was increased by 14.40%-18.2% compared to pristine SnO2. This work includes analysis of Y-doping, thin film, and device characterization. This example demonstrates that it is possible to scale up PSC using inexpensive inorganic ETL with a high throughput process.

[0112] Results and Discussion Pristine tin(IV) oxide (SnO2) and yttrium-doped tin(IV) oxide (Y:SnO2) nanoparticles were synthesized using a sol-gel process as previously described (Chapagain et al. (2021) “Direct Deposition of Nonacoustic SnO2 Dispersion by Blade Coating on Perovskites for the Scalable Fabrication of pin Perovskite Solar Cells” ACS Appl. Energy Mater., Vol. 4, No. 10, pp. 10477-10483), however, yttrium doping was achieved in situ by adding yttrium chloride to the precursor of SnO2 (i.e., anhydrous SnCl4) during the synthesis process. Energy dispersive X-ray spectroscopy (EDS) spectrum of Y:SnO2 reveals the presence of Y in SnO2 along with Sn and O (Figure 16a). Elemental mapping of bulk Y:SnO2 shows a uniform distribution of yttrium in the matrix of Y:SnO2 (Figures 16c, 16d, and 16e). Powder X-ray diffraction (PXRD) was used to analyze the crystal structure of SnO2 and Y:SnO2 nanoparticles (Figure 16b).

[0113] The XRD peaks present at 26.4, 33.75, 51.86, and 64.37° are assigned to the (110), (101), (211), and (301) planes of the tetragonal rutile crystal structure of SnO2 and Y:SnO2. The XRD diffraction pattern of Y:SnO2 does not show extra peaks of impurities which implies that the amount of yttrium is not sufficient to change the crystal structure or is present as a separate phase.

[0114] The elemental composition of the SnO2 and Y:SnO2 thin films was characterized by X-ray photoelectron spectroscopy (XPS). The measured spectrum of Y:SnO2 shows the presence of C1, O1, and Sn 3d peaks along with other associated peaks (Figure 17a). The high-resolution core-level spectrum of Sn 3d shows that the Sn 3d 5 / 2 and Sn3d 3 / 2The doublet peaks at 487.4 eV and 495.8 eV correspond to Sn 3d 5 / 2 and Sn3d 3 / 2 The doublet splitting of SnO2 is 4+ Here, the curves in Fig. 17b are the unfitted Sn 3d curve (solid line), the fitted curve (dashed line), and the Sn 3d 5 / 2 The fitted curves for Sn 3d (long dashed line) and Sn 3d 3 / 2 The curves (short dashed lines) are fitted to the Sn 3d 5 / 2 There is no significant difference in the lineshape of Y:SnO2 (data not shown). Figure 17c shows the presence of an yttrium 3d peak in Y:SnO2 at BE 158.8 eV, which is absent in SnO2. The EDS and XPS results demonstrate good doping of SnO2 with yttrium.

[0115] Direct deposition of SnO2 and Y:SnO2 nanoparticles onto perovskite thin films can be achieved by dispersion of the nanoparticles in perovskite-compatible organic solvents. In Example A above, we functionalized SnO2 with acetate ligands to produce functionalized SnO2 (SnO2-A) dispersible in absolute ethanol. Here, we employed the same strategy for functionalization of Y:SnO2 nanoparticles with acetate to give rise to Y:SnO2-A. Functionalization of Y:SnO2 with acetate transforms the white amorphous tin oxide powder into a colorless, transparent solution of functionalized tin oxide (Y:SnO2-A). The X-ray diffraction (XRD) patterns of Y:SnO2 before and after functionalization (data not shown) have similar peaks at 26.4, 33.75, 51.86, and 64.37°, which are assigned to the (110), (101), (211), and (301) planes of the tetragonal rutile crystal structure of Y:SnO2. XRD analysis shows that there is no change in the crystal structure of Y:SnO2 after functionalization. The FTIR spectrum of SnO2 before functionalization shows a peak at 3300 cm, which is associated with the OH stretching of adsorbed water on the surface of Y:SnO2. -1 Broadband and 1640cm-1 The OH stretching bands are decreased in the FTIR spectrum of Y:SnO2-A, indicating that the hydroxyl groups on the surface of Y:SnO2 are replaced by acetate ligands, and the coordination of acetate in Y:SnO2-A shows sharp bands at 1715 and 1380 cm associated with the CO stretching and scissoring vibrations of acetate ligands. -1 In addition, the FT-IR spectra of Y:SnO2 and Y:SnO2-A show a band at 650 cm associated with the Sn-O stretching. 1 Therefore, the functionalization process of SnO2 and Y:SnO2 is simply a ligand exchange process, as revealed by XRD and FT-IR analyses.

[0116] A general scheme for functionalizing Y:SnO2 nanoparticles with acetate to obtain Y:SnO2-A and ink formulations from Y:SnO2 in absolute ethanol is shown in Figure 18a. In contrast to Y:SnO2, Y:SnO2-A nanoparticles are easily dispersed in protic organic solvents such as ethanol, isopropanol, and butanol. Without being bound by theory, the improved dispersibility of Y:SnO2-A nanoparticles in protic organic solvents may be due to the formation of hydrogen bond networks between surface-bound acetate, excess acetic acid, and alcohol.

[0117] A dispersion of Y:SnO2-A nanoparticles can be deposited directly on top of the perovskite layer via blade coating. After deposition, excess solvent can be quickly removed using a dry air knife. Annealing at 100 °C for 2-3 minutes now ensures complete removal of the solvent. See Figure 18b.

[0118] Figures 18c and 18d are top-view SEM images of the perovskite before and after Y:SnO2-A deposition, revealing a continuous and uniform layer of SnO2. In addition, no formation of lead iodide peaks was observed, indicating that the perovskite was not damaged during deposition.

[0119] The XRD patterns of the perovskite before and after deposition of a Y:SnO2-A dispersion in absolute ethanol on the perovskite (Figure 19a) further demonstrate that the deposition does not affect the perovskite. The XRD pattern of the perovskite before deposition of Y:SnO2-A shows a single prominent peak at 14.1°, as expected for CH3NH3PbI3. The XRD pattern does not change after deposition of Y:SnO2-A, indicating that the perovskite layer remains intact. No additional peak is observed at 12.7°, indicating that no moisture-mediated decomposition leading to the formation of PbI2 has occurred. Figure 19b shows the UV-Vis absorption spectra of the perovskite before and after deposition of Y:SnO2-A. The UV-Vis absorption spectra of the perovskite before and after deposition of Y:SnO2-A on the perovskite are comparable, with no significant change in the optical absorption of the perovskite film. In addition, there is no change in the band edges of the absorption spectrum. The UV-Vis analysis results indicate that Y:SnO2-A does not affect the crystallinity and grain size of the perovskite.

[0120] Steady-state photoluminescence (PL) measurements were carried out to understand the charge carrier dynamics between the perovskite active layer and SnO2-A and Y:SnO2-A (FIG. 20). The perovskite film on the PET substrate exhibited the highest PL intensity, while the perovskite films with SnO2-A and Y:SnO2-A show significant PL quenching. It was observed that the Y:SnO2-A ETL showed higher PL quenching compared to pristine SnO2-A, indicating that the charge transfer at the perovskite / Y:SnO2-A interface is more efficient than that at the perovskite / SnO2-A interface.

[0121] To analyze the effect of yttrium concentration in Y:SnO2-A on the photovoltaic performance of PSCs, a series of planar PSCs were fabricated on flexible PET / ITO-based substrates (f-PSCs) using diluted SnO2-A and Y:SnO2-A as ETLs. The overall device structures are ITO / PTAA / PFN / CH3NH3PbI3 / SnO2-A / BCP / Ag and ITO / PTAA / PFN / CH3NH3PbI3 / Y:SnO2-A / BCP / Ag, where polytriarylamine (PTAA) is used as the hole transport layer (HTL) and poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-ortho-2,7-(9,9-dioctylfluorene)] (PFN) is used as the interfacial layer. Here, the PTAA, PFN, perovskite, and SnO2 layers were deposited by one-step blade coating method, while the BCP and silver were deposited by thermal evaporation. These fabricated f-PSCs were measured under simulated sunlight of AM1.5. Before the measurements, the solar simulator was calibrated using an NREL-certified silicon reference photodiode using a KG5 filter.

[0122] The device performance statistics of f-PSCs versus yttrium doping concentration are shown in Figure 21. The PCE increases with increasing yttrium concentration, with optimal performance achieved at 2 mol% yttrium in Y:SnO2. The increase in PCE is proportional to the open circuit voltage (V oc ) and fill factor (FF). oc The increase in indicates the improved conductivity after yttrium doping. The photovoltaic performance statistics of f-PSCs with SnO2 and Y:SnO2 ETLs are summarized in Table D1. Table D1. Effective area 0.1 cm 2 Summary of average photovoltaic performance statistics of f-PSCs with 0, 1, 2, and 3 mol% yttrium in the SnO2 ETL [Table 4]

[0123] The image of the blade-coated f-PSC is shown in Figure 22a. It is noteworthy that the PCE of the champion f-PSC with 2% Y:SnO2-A is about 4% higher than that of the champion f-PSC with pristine SnO2-A. The device with 2% Y:SnO2-A has a J sc is 24.34mA / cm 2 and V oc It exhibited a champion PCE of 18.19%, with a Vref of 1.08 V and a FF of 68.77% (Fig. 22b). Figure 22c highlights the minimal hysteresis between forward and reverse scans for the f-PSC with 2% Y:SnO2 as the ETL.

[0124] conclusion We synthesized yttrium-doped tin(IV) oxide (Y:SnO2) via in-situ addition of yttrium chloride to the sol-gel synthesis of SnO2. Both pristine SnO2 and Y:SnO2 nanoparticles were functionalized with acetate and diluted with absolute ethanol to give rise to non-aqueous dispersions of SnO2-A and Y:SnO2-A. As revealed by XRD and UV-Vis, the non-aqueous dispersions of SnO2-A and Y:SnO2-A induced no observable damage to the perovskite during deposition by blade coating. PL analysis indicates that Y:SnO2-A has better charge carrier motion states than pristine SnO2-A. We successfully fabricated inverted f-PSCs on PET substrates by directly depositing fully solution-processed SnO2-A and Y:SnO2-A on the perovskite by a scalable blade coating method. The f-PSCS with Y:SnO2-A as the ETL exhibits improved performance compared to the pristine SnO2-A. The optimal yttrium concentration is 2 mol%, which results in a 20% increase in average performance, and V oc It was found that both the ZnO content and FF increased. The low-temperature synthesized Y:SnO2-A is a promising ETL and blocking layer that is fully solution-processed. This material has various cost, scalability, and manufacturing advantages compared to traditional organic ETLs that can improve the competitiveness of commercial perovskite solar modules.

[0125] Experimental Section Synthesis of SnO2 and Y:SnO2 Both SnO2 and Y:SnO2 nanoparticles were synthesized by the sol-gel method by neutralizing 1 M tin(IV) chloride aqueous solution with 5 M sodium hydroxide solution. SnO2 and Y:SnO2 nanoparticles were synthesized similarly, but yttrium doping was achieved in situ by adding yttrium precursor to the tin oxide precursor during the synthesis process. 1 M tin(IV) chloride aqueous solution was prepared by adding anhydrous tin(IV) chloride dropwise to deionized (DI) water. Freshly prepared aqueous solution of 5 M sodium hydroxide was added dropwise to the continuously stirred tin(IV) chloride aqueous solution until the pH reached 6.5. The resulting white precipitate of SnO2 was aged for 12 h, collected by centrifuge, and repeatedly washed by dispersion in DI water and in a 1:1 mixture of DI water and ethanol by centrifuge until the aqueous layer was chloride-free. The washed SnO2 nanoparticles were dried at room temperature. To prepare 1, 2, and 3 mol.% yttrium-doped SnO2, respectively, a calculated amount of yttrium(III) chloride hydrate was added to a 1 M tin(IV) chloride aqueous solution.

[0126] Functionalization of SnO2 and Y:SnO2 with acetate Both SnO2 and Y:SnO2 were functionalized with acetate based on the examples discussed herein. Here, SnO2 or Y:SnO2 were mixed with glacial acetic acid in a 1:1 mass to volume ratio. The mixture of SnO2 and glacial acetic acid or Y:SnO2 and acetic acid was then heated at reflux for 1 hour in a closed vessel equipped with a condenser and a thermometer. The mixture initially forms a milky colloidal dispersion, which becomes clear once functionalization is complete. The presence of undissolved SnO2 nanoparticles leaves a milky coloration that can be removed via centrifugation. The percentage of SnO2 in the clear solution of functionalized SnO2 was determined from TGA analysis, and the functionalized SnO2 nanoparticles were characterized by XRD, FT-IR, and UV-Vis methods. For XRD and FTIR analysis, any solvent present in the functionalized tin(IV) oxide nanoparticles was evaporated and the solid product was dried in a vacuum oven at 100°C for 2 hours before analysis. Functionalized SnO2 and Y:SnO2 were diluted with absolute ethanol to obtain 1.5% (m / v) SnO2 suitable for blade coating on perovskites.

[0127] Device fabrication ITO-PET substrates were cut to a size of 6×8 inches, sprayed with an air gun, and wiped with IPA. Immediately after treating these cleaned PET substrates with UV-ozone for 15 minutes, PTAA, PFN, CH3NH3PbI3, and SnO2 or Y:SnO2 dispersions were sequentially deposited by blade coating inside a dry box. The PTAA solution was prepared by dissolving 8 mg of PTAA in 1 mL of toluene. 60 μL of the PTAA solution was used for blade coating with a coating speed of 10 mm / s and a blade gap of 100 μm, followed by heating at 100 °C for 10 minutes and then cooling to room temperature. Next, 60 μL of a 0.4 mg / mL PFN solution in methanol was blade coated onto the PTAA layer with a coating speed of 10 mm / s and a blade gap of 100 μm. Perovskite precursor solutions were prepared by dissolving methylammonium iodide and lead iodide in a mixture of DMF / DMSO / NMP in a volume ratio of 0.91:0.07:0.02 to obtain a 1.2 M solution. 70 μL of the perovskite precursor solution was deposited by blade coating with a blade gap of 150 μm at a coating speed of 10 mm / s. Immediately after deposition of the perovskite precursor solution, the wet film was pre-dried using a N2 air knife and subsequently hotplate annealed at 140 °C for 2 min. Finally, 60 μL of SnO2-A or Y:SnO2-A dispersion in absolute ethanol was deposited on the perovskite at a blade gap height of 100 μm and a coating speed of 10 mm / s, followed by annealing at 100 °C for 2–3 min. Device architectures and active areas of 0.1 cm for PET-ITO / PTAA / PFN / CH3NH3PbI3 / BCP / SnO2-A / Ag and PET-ITO / PTAA / PFN / CH3NH3PbI3 / BCP / Y:SnO2-A / Ag 2 The fabrication of a PSC with was completed by depositing 5 nm of BCP and 100 nm of silver using thermal evaporation.

[0128] physical method X-ray photoelectron spectroscopy (XPS): VG Scientific MultiLab 3000

[0129] Energy dispersive X-ray spectroscopy (EDS) spectrum: TESCAN Vega3 SEM with EDS detector

[0130] Powder XRD patterns were obtained using a Bruker D8 Discover X-ray diffractometer.

[0131] Infrared spectra were collected using a Thermo Nicolet Avatar 360 FT-IR spectrometer equipped with a Smart iTR.

[0132] UV-Vis analysis was performed on an Agilent 8453 UV-Vis spectrometer.

[0133] Top cross-sectional SEM images were obtained using a JEOL7000 field emission scanning electron microscope. PL analysis was performed using a Renishaw Via Raman microscope equipped with a CCD detector and a 632 nm He-Ne laser source. The current density-voltage (JV) characteristics of the devices were measured using a class AAA solar simulator with a xenon arc lamp under one sun condition (AM1.5G, 100 mW / cm2). Prior to device measurements, the solar simulator was calibrated using an NREL certified Si reference cell. The devices were tested from 1.2 to 0 V with a scan rate of 100 mV / s and a step size of 10 mV.

[0134] Example E - Yttrium doping of SnO2 A series of yttrium-doped tin(IV) oxide (Y:SnO2) nanoparticles (NPs) were synthesized using a slight modification of the sol-gel process we recently reported for the synthesis of the original tin(IV) oxide (SnO2) particles (Chapagain et al. (2021) “Direct Deposition of Nonaqueous SnO2 Dispersion by Blade Coating on Perovskites for the Scalable Fabrication of pin Perovskite Solar Cells” ACS Appl. Energy Mater., Vol. 4, No. 10, pp. 10477-10483). For the synthesized Y:SnO nanoparticles, yttrium chloride was added in an appropriate ratio to an aqueous solution of anhydrous SnCl4 during the synthesis process to obtain Y:SnO2 1%, Y:SnO2 2%, and Y:SnO2 3% (Figure 23).

[0135] To enhance dispersibility in perovskite-affinity organic solvents, Y:SnO2NPs were functionalized with acetate to yield Y:SnO2-A. Acetate functionalization converts the amorphous white powder of Y:SnO2 into a colorless, transparent solution of functionalized tin oxide (Y:SnO2-A) in glacial acetic acid. Here, Y:SnO2 was mixed with glacial acetic acid in a 1:1.25 mass volume ratio, as shown in Figure 23. However, the ratio of Y:SnO2 to acetic acid varies depending on the application. The mixture of Y:SnO2 and glacial acetic acid was then heated at reflux for 1 hour in a closed vessel equipped with a condenser and thermometer. The mixture initially forms a milky white colloidal dispersion, which becomes transparent once functionalization is complete. The presence of undissolved Y:SnO2 nanoparticles leaves a milky white coloration that can be removed via centrifugation. The percentage of Y:SnO2 in the clear solution of functionalized Y:SnO2 (Y:SnO2) was determined from TGA analysis, and the Y:SnO2-A nanoparticles were characterized by XRD, FT-IR, and UV-Vis techniques. For XRD and FTIR analysis, any solvent present in the functionalized tin(IV) oxide nanoparticles was evaporated and the solid product was dried in a vacuum oven at 100 °C for 2 h before analysis. Y:SnO2-A was diluted with absolute ethanol to obtain 1.5% (m / v) SnO2 suitable for blade coating on perovskites.

[0136] The photovoltaic performance of perovskite solar cells versus concentration Y:SnO2 is shown in Figures 24 and 25 for forward (F) and reverse (R) measurements.

[0137] Example Set F The perovskite ink was prepared by dissolving PbI2 and MAI in dimethylsulfoxide (DMSO, 7%), N-methyl-2-pyrrolidone (NMP, 2%), and dimethylformamide (DMF, 91%) to make a 1.2 M solution by gentle stirring. The perovskite was applied by blade coating with a blade gap of 100 μm at a speed of 10 mm s at room temperature. -1After perovskite deposition, the films were dried using a N2 knife at 40 psi pressure and then annealed at 140 °C for 2 min. x The ink was prepared by dissolving NiO in 200 μL of a 3:1 (v / v) EtN / EtOH mixture. x Particles (20 mg) were prepared by sonication in a closed vial for 60 min at 65° C. The resulting suspension was diluted with 700 μL of CB and 100 μL of EtOH to obtain NiO x A 20 mg / mL solution was made. After dilution, the suspension was heated at 65°C and sonicated. Prior to blade coating, the hot ink suspension was filtered through 0.2 μm PTFE. NiO x Ink 40μL -2 At a speed of 5 mm / sec -1 was deposited on the perovskite by blade coating using an optimized blade gap of 225 μm.

[0138] Pure NiO x The results (without added PA) confirm successful solution-phase deposition on perovskite. The XRD patterns of methylammonium lead iodide (MAPI) on ITO before and after deposition (Figure 26a) are nearly identical with a prominent MAPI peak at 14.1 and no detectable PbI2 decomposition peak at 12.7. x Photoluminescence (PL) studies with and imidazolium PA (Figure 26b) confirm the additional benefit of including a multifunctional passivator. Imidazolium was deposited on the perovskite surface by blade coating. Imidazolium was suspended in EtOH at a concentration of 0.04 mg / mL solution and coated at 10 mm / s with a blade height of 100 μm. NiO on MAPI x The deposition of NiO on our multifunctional imidazolium PA reduces the PL intensity associated with charge extraction. x The charge extraction is improved by adding 14.47% (0.25 cm 2 ) and 9.60% (1.0 cm 2 ) efficiency, NiO xThe NiO nanoparticles on MAPI were prepared using solution-phase deposition. The JV curves show that the series and shunt resistances affect the device performance. In particular, the same solvent system was used to fabricate NiO nanoparticles on MAPI. x and SnO2 deposition, only the latter of which has provided functional devices so far. In these two cases, there may be surface differences that can be mediated by the inclusion of an interfacial passivation layer.

[0139] A heading used in this disclosure is not meant to imply that all disclosure relating to the heading is found in the section beginning with that heading, but rather that disclosure of any subject matter may be found throughout the entire specification.

[0140] It should be noted that terms such as "preferably," "generally," and "typically" are not used herein to limit the scope of the claimed invention or to imply that a particular feature is critical, essential, or essential to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the invention.

[0141] As used in this disclosure, "a" or "an" means one or more unless otherwise specified. When used in the claims, when used with the word "comprising", the word "a" or "an" can mean one or more than one unless otherwise specified. When used in this disclosure or claims, "another" means at least a second or more unless otherwise specified. When used in this disclosure, the words "such as", "for example", and "eg" mean "for example, but not limited to", in that the list following that term ("such as", "for example", or "eg") provides some examples, but the list is not necessarily an entirely exhaustive list. The word "comprising" means that the items following the word "comprising" may include additional unrecited elements or steps, i.e., "comprising" does not exclude additional unrecited steps or elements.

[0142] Unless otherwise indicated, all numbers expressing properties such as quantities of ingredients, reaction conditions, and the like used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought by the presently disclosed subject matter.

[0143] As used herein, the term "about," when referring to a value or amount of mass, weight, time, volume, concentration, or percentage, is meant to encompass variations in some embodiments of ±20%, in some embodiments of ±10%, in some embodiments of ±5%, in some embodiments of ±1%, in some embodiments of ±0.5%, and in some embodiments of ±0.1%, as appropriate for carrying out the disclosed methods.

[0144] A detailed description of one or more embodiments is provided herein. However, it should be understood that the present invention can be embodied in various forms. Therefore, the specific details disclosed herein (even if specified as preferred or advantageous) should not be construed as limiting, but rather should be used as an exemplary basis for the claims and as a representative basis for teaching a person skilled in the art to use the present invention in any suitable manner. Indeed, various modifications of the present invention in addition to those described herein will become apparent to a person skilled in the art from the foregoing description and the accompanying drawings. Such modifications are intended to fall within the scope of the appended claims.

Claims

1. 1. A method for preparing a perovskite solar cell (PSC), the method comprising: - dissolving a functionalized material in a solvent, said functionalized material being a material that has been functionalized with one or more functionalizing compounds; - depositing a deposition composition onto the perovskite layer, said deposition composition comprising a dissolved functionalizing material; - heating the deposition composition; - optionally removing some or all of the one or more functionalizing compounds from the deposition composition.

2. 10. The functionalized material of claim 1, wherein the functionalized material comprises: (a) Organic materials, metal oxides, TiO ２ , SnO ２ , NiO ｘ , CuO, ZnO, Zn ２ SO ４ , W.O. ３ , In ２ O ３ , SrTiO ３ , Nb ２ O ５ , BaSnO ３ , C ６０ , C ７０ , PC ６１ BM, PC ７１ BM or fullerene; and / or (b) an organic material, a metal oxide, a doped metal oxide, TiO2, SnO2, NiOx, CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiOx, C60, C70, PC61BM, PC71BM, or a fullerene; and / or (c) a metal oxide, a doped metal oxide, TiO2, SnO2, NiOx, CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, Cu:NiOx, C60, C70, PC61BM, PC71BM, or a fullerene; and / or (d) TiO2, SnO2, NiOx, CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, Y:SnO2, or Cu:NiOx; and / or (e) SnO2, NiOx, Y:SnO2, or Cu:NiOx, The method of claim 1 , comprising:

3. The material comprises one or more of the following doping substances:

10. The method of claim 1, wherein the one or more doping materials comprise Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo.

4. the one or more functionalizing compounds (1)R １ａ -CO-OH(I)、 or a salt thereof, wherein R １ａ is substituted or unsubstituted alkyl, (I) or a salt thereof; (2) R ２ａ -O-CS ２ － M ＋ ２ａ (II) In the formula, R ２ａ is a substituted or unsubstituted alkyl; M ＋ ２ａ is a cation, (II), 【Chemical 1】 And, In the formula, X ３ is an anion, and R ３ａ , R ３ｃ , R ３ｄ , and R ３ｅ are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R ３ｂ is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted Lewis base, quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; (IIIa) or (IIIb), 【Chemistry 2】 And, In the formula, X ４ is an anion, and R ４ａ , R ４ｃ , R ４ｄ , R ４ｅ , R ４ｆ , and R ４ｇ are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R ４ｂ is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted Lewis base, quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; (IVa) or (IVb), 【Chemistry 3】 And, In the formula, R ５ａ , R ５ｂ , and R ５ｃ are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; (V); 【Chemistry 4】 And, In the formula, R ６ｂ , R ６ｃ , and R ６ｄ are the same or different and are H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R ６ａ is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, R ６ａ the substituted alkyl is optionally substituted with one or more substituted or unsubstituted Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; R ６ａ The substituted aryl is optionally substituted with one or more substituted or unsubstituted Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; (VI); or (7) R ７ａ -NH-CS ２ － M ＋ ７ａ (VII) In the formula, R ７ａ is a substituted or unsubstituted alkyl; M ＋ ２ａ is one or more of (VII), R 1a is substituted or unsubstituted C 1 -C 8 alkyl, methyl, ethyl, propyl, or butyl; and / or R 2a is substituted or unsubstituted alkyl C 1 -C 36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl, or M + 2a is Na + , K + , or Li + , or a combination thereof; and / or X 3 is Cl − , Br − , I − , BF 4 − , PF 6 − , or CF 3 SO 3 − , R 3a , R 3c , R 3d , and R 3e are the same or different and are H, substituted or unsubstituted C 1 -C 8 alkyl, or substituted or unsubstituted phenyl, R 3b is H, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted phenyl, —C(O)H, —C(O)OH, —C(O)NHR 3f , —CH 2 OR 3f , —CH 2 NHR 3f , quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate, and R 3f is H, substituted or unsubstituted C 1 -C 8 alkyl, or a combination thereof; and / or X 4 is Cl − , Br − , I − , BF 4 − , PF 6 − or CF 3 SO 3 − ; R 4a , R 4c , R 4d , R 4e , R 4f and R 4g are the same or different and are H, substituted or unsubstituted C 1 -C 8 alkyl or substituted or unsubstituted phenyl; R 4b is H, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted phenyl, —C(O)H, —C(O)OH, —C(O)NHR 4h , —CH 2 OR 4h , —CH 2 NHR 4h , quaternary nitrogen salt, carboxylate, xanthate, alkoxide or thiolate; alkyl, or combinations thereof; and / or R 5a , R 5b and R 5c are the same or different and are H, substituted or unsubstituted C 1 -C 8 alkyl, or substituted or unsubstituted phenyl; and / or R 6b , R 6c and R 6d are the same or different and are H, substituted or unsubstituted C 1 -C 8 alkyl, or substituted or unsubstituted phenyl; or R 6a is H, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted phenyl, said R 6a substituted alkyl optionally being substituted with one or more of -C(O)H, -C(O)OH, -C(O)NHR 6e , -CH 2 OR 6e , -CH 2 NHR 6e , quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate; and said R 6a substituted aryl optionally being substituted with one or more of -C(O)H, -C(O)OH, -C(O)NHR 6e , -CH 2 OR 6e , -CH 2 NHR 6e , quaternary nitrogen salt, carboxylate, xanthate, alkoxide, or thiolate, and R 6e is H, substituted or unsubstituted C 1 -C 8 alkyl, or a combination thereof; and / or R 7a is substituted or unsubstituted alkyl C 1 -C 36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl, or M + 7a is Na + , K + , or Li + , or a combination thereof; Optionally, formula (IIIb) is: 【Chemistry 5】 and / or optionally, 2. The method of claim 1, wherein formula (V) is selected from triarylamine (TAA), substituted TAA, triphenylamine, substituted triphenylamine, triethylamine, and substituted triethylamine.

5. the functionalized material is (a) Metal oxides, doped metal oxides, TiO ２ , SnO ２ , NiO ｘ , CuO, ZnO, Zn ２ SO ４ , W.O. ３ , In ２ O ３ , SrTiO ３ , Nb ２ O ５ , BaSnO ３ , Y: SnO ２ , Cu:NiO ｘ , C ６０ , C ７０ , PC ６１ BM, PC ７１ BM, or fullerene, each independently represents (i) a group of formula １ａ is C １ -C ４ (ii) one or more of formula (I) or a salt thereof, wherein R ２ａ is C １ -C ２７ is alkyl, and M ＋ ２ａ is Na ＋ , K. ＋ , or Li ＋ (iii) triethylamine, or (iv) a combination thereof; and / or (b) comprising one or more of a metal oxide, a doped metal oxide, TiO2, SnO2, NiOx, CuO, ZnO, Zn2SO4, WO3, In2O3, SrTiO3, Nb2O5, BaSnO3, C60, C70, PC61BM, PC71BM, or a fullerene, each independently functionalized with one or more of formula (I) or a salt thereof, wherein R1a is C1-C4 alkyl; and / or (c) one or more of TiO2, ZnO, Y:SnO2, Cu:NiOx, NiOx, or SnO2, each independently functionalized with acetate, propionate, triethylamine, NaCi8 alkyl xanthate, NaCi2 alkyl xanthate, or combinations thereof; and / or (d) one or more of TiO 2 , ZnO, NiO x , or SnO 2 , each independently functionalized with one or both of acetate or propionate; The method of claim 1.

6. (a) The solvent is a protic solvent, an anhydrous protic solvent, anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, anhydrous C １－１０ alcohol, THF, dimethyl ether, diethyl ether, anhydrous ether, ether, chlorobenzene (CB), or a combination thereof; and / or 10. The method of claim 1, wherein (b) the depositing step is performed by one or more of blade coating, spin coating, slot die, gravure, flexography, spraying, or inkjet, such as blade coating.

7. The heating step comprises: (a) annealing or intense pulsed light (IPL); and / or (b) heating at about 80°C to about 120°C for about 5 to about 20 minutes; and / or (c) removing some or all of the one or more functionalizing compounds; The method of claim 1.

8. The method of claim 1 , wherein the removing step occurs, for example, by heat or by intense pulsed light (IPL).

9. 10. The method of claim 1, wherein (i) the heating step removes a portion of the one or more functionalizing compounds, and (ii) the removing step occurs to further remove some or all of the remaining one or more functionalizing compounds.

10. The perovskite layer is (a) one or more of CH 3 NH 3 PbX 3 , CH 3 NH 3 PbI 3 , H 2 NCHNH 2 PbX 3 , CH 3 NH 3 SnX 3 , or Cs a (CH 5 NH 3 ) b (CH 3 NH 3 ) c PbI 3(1-y) Br 3y , where X is a halogen which may be the same or different between or within each formula, a is from about 0 to about 0.5, b is from about 0 to about 0.8, c is from about 0 to about 0.8, and y is from about 0 to about 1; and / or (b) is part of a structure further comprising one or more of an anode, a hole transport layer (HTL), or a cathode; and / or (c) is part of a structure further comprising one or more of an anode, an electron transport layer (ETL), or a cathode; The method of claim 1.

11. The method comprises: (a) further comprising adding a cathode; and / or (b) further comprising adding a cathode, wherein the method for adding the cathode is screen printing, thermal evaporation, sputtering, or atomic layer deposition; and / or (c) further comprising adding a cathode, wherein the method for adding the cathode is thermal evaporation; and / or (d) further comprising adding a cathode, wherein the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu; and / or (e) further comprising adding a cathode, wherein the cathode is Ag, Al, or Cu; The method of claim 1.

12. The PSC is (a) an open circuit voltage (Voc) of about 0.7 V to about 1.3 V; and / or (b) having a fill factor (FF) of about 35% to about 80%; and / or (c) having a current density (J sc ) of about 10 mA / cm 2 to about 25 mA / cm 2 ; and / or (d) having a power conversion efficiency (PCE) of between about 4% and about 20%; and / or (e) is a flexible PSC; The method of claim 1.

13. A PSC produced according to claim 1.

14. The PSC of claim 13, comprising an interface layer.

15. 13. A device comprising an anode, a hole transport layer (HTL), an electron transport layer (ETL) and a perovskite layer prepared according to any one of claims 1 to 12; and a cathode, optionally comprising: The anode is ITO / glass or FTL / glass, and optionally, C. the HTL is NiO x , PTAA or PTAA / PFN, and optionally the perovskite layer is one or more of CH 3 NH 3 PbX 3 , CH 3 NH 3 PbI 3 , H 2 NCHNH 2 PbX 3 or CH 3 NH 3 SnX 3 , where X is a halogen which may be the same or different between or within each formula, and optionally 14. The PSC of claim 13, wherein the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu; and / or Ag, Al, or Cu.

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