Cross-linked surface coatings and interfacial layers for perovskite material photovoltaic devices

Abstract

The photovoltaic device includes a photoactive material including a perovskite material, a cross-linked polymer including a fullerene or a fullerene derivative, and an interfacial layer including a cross-linker and one or more polymers selected from the group consisting of polystyrene, [6,6]-phenyl-C61-butyric acid methyl ester, poly(4-vinylphenol), [6,6]-phenyl-C61-butyric acid, and any combination thereof.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 941,320, filed on November 27, 2019, entitled "Cross - Linked Surface Coating and Interface Layer for Perovskite Material Photovoltaic Devices", the content of which is hereby incorporated by reference in its entirety.

Background Art

[0002]

[0002] Using photovoltaic (PV) to generate electricity from solar energy or radiation can provide many benefits, such as power supply, low - or zero - emissions gas, power production independent of the power grid, a durable physical structure (without moving parts), a stable and reliable system, a modular structure, relatively rapid installation, safe manufacturing and use, and favorable public opinion and acceptance of use.

[0003]

[0003] PV can incorporate a layer of perovskite material as a photoactive layer that generates electricity when exposed to light. Additional layers within the PV device can assist in transporting charges from the photoactive layer. The selection of the charge - transport layer can affect the performance and durability of the PV device.

[0004]

[0004] The features and advantages of the present disclosure will be readily apparent to those skilled in the art. Those skilled in the art can make many modifications, but such modifications are within the scope of the spirit of the present invention.

Summary of the Invention

[0005]

[0005] In one embodiment, a method for manufacturing a perovskite material photovoltaic device includes depositing a perovskite material, depositing a layer of fullerenes, depositing a halosilylalkane, and heating an alkyl hydroxide to bond the halosilylalkane to the fullerenes.

[0006]

[0006] In one embodiment, the crosslinked polymer includes a halosilylalkane and one or more monomers selected from the group consisting of polystyrene, [6,6]-phenyl-C61-butyric acid methyl ester, poly(4-vinylphenol), [6,6]-phenyl-C61-butyric acid, and combinations thereof.

[0007]

[0007] In one embodiment, the photovoltaic device includes a photoactive material including a perovskite material. The photovoltaic device also includes an interfacial layer including a crosslinked polymer including a halosilylalkane and one or more monomers selected from the group consisting of polystyrene, [6,6]-phenyl-C61-butyric acid methyl ester, poly(4-vinylphenol), [6,6]-phenyl-C61-butyric acid, and combinations thereof.

Brief Description of the Drawings

[0008]

Figure 1

[0008] FIG. is a schematic diagram of a conventional photovoltaic (PV) cell including an active layer according to an embodiment of the present disclosure.

Figure 2

[0009] FIG. is a stylized diagram showing the components of an exemplary PV device according to an embodiment of the present disclosure.

Figure 3

[0010] FIG. is a stylized diagram showing the components of an exemplary device according to an embodiment of the present disclosure.

Figure 4

[0011] FIG. is a stylized diagram showing the components of an exemplary device according to an embodiment of the present disclosure.

Figure 5

[0012] FIG. is a stylized diagram showing a Ruddlesden-Popper perovskite.

Figure 6

[0013] FIG. is a stylized diagram showing an illustration of a perovskite material with an alkylammonium cation added according to an embodiment of the present disclosure.

Figure 7

[0014] A stylized diagram showing an illustration of a perovskite material with a 1-butylammonium surface layer, according to an embodiment of the present disclosure.

Figure 8

[0015] A stylized diagram showing an illustration of a perovskite material with a surface layer of multiple bulky organic cations, according to an embodiment of the present disclosure.

[0016] FIG. 8A is a stylized diagram showing an illustration of a perovskite material with a surface layer of multiple bulky organic cations, according to an embodiment of the present disclosure.

Figure 9

[0017] An explanatory diagram by comparison of images taken of perovskite materials with and without a 1-butylammonium ("BAI") surface coating, according to an embodiment of the present disclosure.

Figure 10

[0018] A stylized diagram showing a comparative example of images taken of perovskite materials with and without a 1-butylammonium ("BAI") surface coating, according to an embodiment of the present disclosure.

Figure 11

[0019] A - D show various perylene monoimides and diimides that can be applied to the surface of a perovskite material, according to an embodiment of the present disclosure.

Figure 12

[0020] A stylized diagram showing an explanatory diagram of adding a perylene monoimide ammonium cation to a perovskite material, according to an embodiment of the present disclosure.

Figure 13

[0021] A stylized diagram showing an illustration of 1,4-diammonium butane incorporated into the crystal lattice of a lead iodide perovskite material, according to an embodiment of the present disclosure.

Figure 14

[0022] An explanatory diagram of the X-ray diffraction peaks (XRD) of perovskite with various concentrations of 1,4-diammonium butane, according to an embodiment of the present disclosure.

Figure 15

[0023] Images over time of perovskite material samples with various concentrations of 1,4-diammonium butane are provided, according to an embodiment of the present disclosure.

Figure 16

[0024] A diagram of a polyammonium alkyl cation according to an embodiment of the present disclosure.

[0025] FIG. 16A is a stylized diagram showing an illustration of 1,8-diammonium octane incorporated into the crystal lattice of a formamidinium lead iodide perovskite material according to an embodiment of the present disclosure.

[0026] FIG. 16B is an explanatory diagram of bis(4-aminobutyl)-ammonium incorporated into the crystal lattice of a lead iodide perovskite formamidinium material according to an embodiment of the present disclosure.

[0027] FIG. 16C is an explanatory diagram of tris(4-aminobutyl)-ammonium incorporated into the crystal lattice of a formamidinium lead iodide perovskite material according to an embodiment of the present disclosure.

Figure 17

[0028] A diagram of the structure of a specific organic molecule according to an embodiment of the present disclosure.

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

[0029] It shows the X-ray diffraction pattern of a perovskite material according to an embodiment of the present disclosure.

Figure 30

[0030] It is a stylized diagram of the thickness of the inorganic metal halide sublattice of a perovskite material according to an embodiment of the present disclosure.

Figure 31

[0031] It shows the optical and photoluminescence images of a perovskite material photovoltaic device according to an embodiment of the present disclosure.

Figure 32

[0032] It shows the power output curve of a perovskite material photovoltaic device according to an embodiment of the present disclosure.

Figure 33

[0033] It shows the current-voltage (I-V) scan of a perovskite material photovoltaic device according to an embodiment of the present disclosure.

Figure 34

[0034] It shows a box plot regarding the open-circuit voltage, short-circuit current density, fill factor, and power conversion efficiency of a perovskite material photovoltaic device according to an embodiment of the present disclosure.

Figure 35

[0035] It shows the external quantum efficiency (EQE) curve of a perovskite material photovoltaic device according to an embodiment of the present disclosure.

Figure 36

[0036] It shows the admittance spectroscopic plot of a perovskite material photovoltaic device according to an embodiment of the present disclosure.

Figure 37

[0037] It is a diagram showing the structure of a crosslinked interfacial layer according to an embodiment.

Figure 38

[0038] It shows the structure of a crosslinked interfacial layer according to an embodiment.

Figure 39

[0039] It shows the structure of a crosslinked interfacial layer according to an embodiment.

Figure 40

[0040] It shows the structure of a crosslinked interfacial layer according to an embodiment.

Figure 41

[0041] It is a diagram showing the structure of a crosslinked interface layer according to an embodiment.

Figure 42

[0042] Shows the structure of a crosslinked interface layer according to an embodiment.

Figure 43

[0043] Shows the structure of a crosslinked interface layer according to an embodiment.

Figure 44

[0044] Shows the structure of a crosslinked interface layer according to an embodiment.

Figure 45

[0045] It is a diagram showing the structure of a crosslinked interface layer according to an embodiment.

Mode for Carrying Out the Invention

[0009]

[0046] Improvements in various aspects of PV technologies compatible with organic PV, inorganic PV, and / or hybrid PV are expected to further reduce the costs of both organic PV and other PVs. For example, certain solar cells, such as perovskite PV solar cells, can utilize new alternative components with high cost-effectiveness and stability, such as nickel oxide interface layers. Furthermore, various types of solar cells may advantageously include chemical additives and other materials that are more cost-effective and durable than currently existing conventional options.

[0010]

[0047] The present disclosure generally relates to the use of compositions of substances, devices, and materials in solar cells when generating electrical energy from solar radiation. More specifically, the present disclosure relates to compositions of photoactive and other substances, as well as the devices, use methods, and formation of such compositions of substances.

[0011]

[0048] Some or all of the materials according to certain embodiments of the present disclosure can advantageously be used in any organic or other electronic device, examples of which include, but are not limited to, batteries, field effect transistors (FETs), light emitting diodes (LEDs), nonlinear optical devices, memristors, capacitors, rectenna, and / or rectifying antennas.

[0012]

[0049] In certain embodiments, the present disclosure can provide PV and other similar devices (e.g., batteries, hybrid PV cells, multi-junction PV, FETs, LEDs, X-ray detectors, gamma ray detectors, photodiodes, CCDs, etc.). In certain embodiments, the device may include an improved active material, an interfacial layer (IFL), and / or one or more perovskite materials. The perovskite materials may be incorporated into various ones of one or more aspects of the PV or other devices. Perovskite materials according to certain embodiments may have the general formula CMX 3 where C includes one or more cations (e.g., amines, ammonium, phosphonium, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds), M includes one or more metals (including Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X includes one or more anions. Perovskite materials according to various embodiments will be described in more detail below.

[0013]

[0050] Electronic devices such as solar cells A PV embodiment can be described with reference to an exemplary illustration of a solar cell as shown in FIG. 1. An exemplary PV architecture according to an embodiment may be substantially in the form of a substrate - anode - IFL - active layer - IFL - cathode. The active layer of an embodiment may be photoactive and / or may include a photoactive material. Other layers and materials may be utilized in the cell as is known in the art. Further, it should be noted that when using the term "active layer", it is not meant to explicitly or implicitly limit or otherwise define the characteristics of any other layer. For example, in some embodiments, one or both of the IFLs may be active as long as they can be semiconductors. In particular, referring to FIG. 1, a stylized general PV cell 1000 is shown, demonstrating high interface characteristics of certain layers within the PV. PV 1000 represents a general architecture applicable to a PV device, such as an embodiment of a perovskite material PV. The PV cell 1000 includes a transparent substrate layer 1010, which may be glass (or a material similarly transparent to solar radiation), allowing solar radiation to pass through the layer. The transparent layer of an embodiment may also be referred to as a superstrate or substrate (similar to the substrate layer 3901 in FIG. 2, for example) and may include any one or more of various rigid or flexible materials such as glass, polyethylene, polypropylene, polycarbonate, polyimide, PMMA, PET, PEN, Kapton, or quartz. Generally, the term "substrate" is used to refer to the material on which the device is deposited during manufacturing. The photoactive layer 1040 may be composed of an electron donor or p - type material, and / or an electron acceptor or n - type material, and / or an ambipolar semiconductor exhibiting both p - type and n - type material characteristics, and / or an intrinsic semiconductor not exhibiting n - type or p - type characteristics. The photoactive layer 1040 may be a perovskite material as described herein in some embodiments. As shown in FIG. 1, the active layer or photoactive layer 1040 is sandwiched between two conductive electrode layers 1020 and 1060. In FIG. 1, the electrode layer 1020 may be a transparent conductor such as indium tin oxide (ITO material) or other materials described herein. In other embodiments, the second substrate 1070 and the second electrode 1060 may be transparent.As described above, the active layer of certain embodiments need not necessarily be photoactive, but in the device shown in FIG. 1, it is photoactive. The electrode layer 1060 may be an aluminum material or other metal, or other conductive material such as carbon. As is known in the art, other materials may be used. Cell 1010 also includes an interfacial layer (IFL) 1030 as shown in the example of FIG. 1. The IFL can assist in charge separation. In other embodiments, the IFL 1030 may include a multilayer IFL, which will be described in more detail below. Also, an IFL 1050 may be present adjacent to the electrode 1060. In certain embodiments, the IFL 1050 adjacent to the electrode 1060 may also or instead include a multilayer IFL (again, described in more detail below). The IFL according to certain embodiments may be semiconductor in nature, either intrinsic, bipolar, p-type, or n-type, or may be dielectric in nature. In certain embodiments, the IFL on the cathode side of the device (e.g., IFL 1050 as shown in FIG. 1) may be p-type, and the IFL on the anode side of the device (e.g., IFL 1030 as shown in FIG. 1) may be n-type. However, in other embodiments, the cathode side IFL may be n-type and the anode side IFL may be p-type. Cell 1010 can be attached to an electrical lead by the electrode 1060 and 1020 and a discharge unit such as a battery, motor, capacitor, power grid, or any other electrical load.

[0014]

[0051] According to various embodiments of the present disclosure, improved materials and / or designs in various aspects of solar cells and other devices are provided, including, among other things, active materials (including hole transport and / or electron transport layers), interfacial layers, and overall device design.

[0015]

[0052] Interface layer In certain embodiments, the present disclosure provides advantageous materials and designs for one or more interfacial layers within a PV, including a thin film coated IFL. The thin film IFL can be used in one or more IFLs of a PV according to various embodiments described herein.

[0016]

[0053] In various embodiments, the device may include an interface layer in any manner between any two other layers and / or materials, or the device may not include any interface layer. For example, a perovskite material device may include zero, 1, 2, 3, 4, 5, or more interface layers (e.g., the exemplary device of FIG. 2 includes five interface layers 3903, 3905, 3907, 3909, and 3911). The interface layer may include any suitable material for enhancing charge transport and / or collection between two layers or materials, and also helps to prevent or reduce the possibility of charge recombination after the charge is transferred from one of the materials adjacent to the interface layer. The interface layer can further physically and electrically homogenize the substrate to cause changes in the roughness, dielectric constant, adhesion, defects (e.g., charge traps, surface states), or quenching of the substrate. Suitable interface materials include Ag, Al, Au, B, Bi, Ca, Cd, Ce, Co, Cu, Cu, Fe, Ga, Ge, H, In, Mg, Mn, Mo, Nb, Ni, Pt, Sb, Sc, Si, Sn, Ta, Ti, V, W, Y, Zn, Zr, carbides of any of the above metals (e.g., SiC, Fe 3 C, WC, VC, MoC, NbC), silicides of any of the above metals (e.g., Mg 2 Si, Si 2 , Sn 2 Si), oxides of any of the above metals (e.g., alumina, silica, titania, SnO 2 , ZnO, NiO, ZrO 2 , HfO 2 ), transparent conductive oxides (「TCO(s)」) such as indium tin oxide, aluminum-doped zinc oxide (AZO), cadmium oxide (CdO), fluorine-doped tin oxide (FTO), sulfides of any of the above metals (e.g., for example, CdS, MoS 2 , SnS 2 ), nitrides of any of the above metals (e.g., GaN, Mg 3 N 2 , TiN, BN, Si 3 N 4 ), selenides of any of the above metals (e.g., CdSe, FeSe 2 , ZnSe), tellurides of any of the above metals (e.g., CdTe, TiTe2 , ZnTe), any phosphide of said metal (e.g., InP, GaP, GaInP), any arsenide of said metal (e.g., CoAs 3 , GaAs, InGaAs, NiAs), any antimonide of said metal (e.g., AlSb, GaSb, InSb), any halide of said metal (e.g., CuCl, CuI, BiI 3 ), any pseudohalide of said metal (e.g., CuSCN, AuCN, Fe(SCN) 2 ), any carbonate of said metal (e.g., CaCO 3 , Ce 2 (CO 3 ) 3 ), a functionalized or non-functionalized alkylsilyl group; graphite; graphene; fullerene; carbon nanotube; any mesoporous material and / or interfacial material discussed elsewhere in this specification; and combinations thereof (in certain embodiments, including bilayers, trilayers, or multilayers of the combined materials). In certain embodiments, the interfacial layer may comprise a perovskite material. Further, the interfacial layer may include embodiments in which any of the interfacial materials described herein are doped (e.g., Y-doped ZnO, N-doped single-walled carbon nanotubes). The interfacial layer may also include a compound comprising three of the above materials (e.g., CuTiO 3 , Zn 2 SnO 4 ) or a compound comprising four of the above materials (e.g., CoNiZnO). The above materials can exist in a planar, mesoporous (porous), or other nanostructured form (e.g., rods, spheres, flower shapes, cones (pyramid forms)), or an aerogel structure.

[0017]

[0054] First, as described above, one or more IFLs (e.g., either or both of the IFLs 2626 and 2627 shown in FIG. 1) may include the photoactive organic compound of the present disclosure as a self-assembled monolayer (SAM) or as a thin film. When the photoactive organic compound of the present disclosure is applied as a SAM, it may include a linking group that can be covalently or otherwise bonded to the surface of either or both of the anode and the cathode through it. The linking group of certain embodiments is COOH, SiX 3 (wherein X is Si(OR) 3 and SiCl 3 or any moiety suitable for forming a ternary silicon compound such as), SO 3 , PO 4 H, OH, CH 2X (wherein X may include a Group 17 halide), and may include any one or more of O, and the linking group may be covalently bonded or otherwise bonded to an electron-withdrawing moiety, an electron-donating moiety, and / or a core moiety. The linking group may adhere to the electrode surface so as to form an organized layer with a thickness of a single molecule (or, in some embodiments, multiple molecules) in a directional manner (i.e., in the case where a plurality of photoactive organic compounds are bonded to the anode and / or cathode). As described above, the SAM may adhere via covalent bonding interactions, but in some embodiments, it may adhere via ionic, hydrogen bonding, and / or dispersion force (i.e., van der Waals) interactions. Further, in some embodiments, upon photoexposure, the SAM enters an zwitterionic excited state, thereby generating a high-polarity IFL that can induce charge carriers from the active layer to the electrode (e.g., anode or cathode). In some embodiments, this enhanced charge carrier injection is achieved by electronically poling the cross-section of the active layer, and thus, the drift velocity of the charge carriers increases towards each electrode (e.g., holes to the anode, electrons to the cathode). The molecule for anode application in some embodiments includes a primary electron-donating moiety bonded to the core moiety, and the core moiety may include a tunable compound that is bonded to an electron-withdrawing moiety and is bonded to the linking group. For cathode applications according to some embodiments, the IFL molecule may include a tunable compound including an electron-deficient moiety bonded to the core moiety, and the core moiety is bonded to an electron-donating moiety and is bonded to the linking group. When the photoactive organic compound is used as the IFL according to this embodiment, it may retain the photoactive properties, but in some embodiments, it may not be photoactive.

[0018]

[0055] The metal oxide can be used in the thin-film IFL of some embodiments, and may include a semiconductor metal oxide, such as NiO, SnO 2 WO 3 、V 2 O 5 、or MoO 3 。A second (e.g., n-type) active material is TiO 2 O 3 coated with a thin-film coated IFL including Al 2Embodiments including, for example, Al(NO 3 ) 3 ·xH 2 O and other precursor materials, or Al 2 O 3 can be formed of any other material suitable for deposition on TiO 2 , and then thermal annealing and dye coating are performed. In an exemplary embodiment where a MoO 3 coating is used instead, the coating may be formed of a precursor material such as Na 2 MO 4 ·2H 2 O, etc. According to some embodiments, a V 2 O 5 coating may be formed of a precursor material such as NaVO 3 , etc. According to some embodiments, a WO 3 coating may be formed of a precursor material such as NaWO 4 ·H 2 O, etc. The concentration of the precursor material (e.g., Al(NO 3 ) 3 ·xH 2 O) may affect the final film thickness deposited on TiO 2 or other active materials (here, the film thickness of Al 2 O 3 ). Therefore, changing the concentration of the precursor material can be a way to control the final film thickness. For example, increasing the concentration of the precursor material may result in a thicker film thickness. Even if the film thickness is large, the PCE of a PV device including a metal oxide coating does not necessarily increase. Therefore, the method of an embodiment may include coating a TiO 2 (or other mesoporous) layer with a precursor material having a concentration in the range of about 0.5 to 10.0 mM. Other embodiments may include coating the layer with a precursor material having a concentration in the range of about 2.0 to 6.0 mM, or other embodiments may include coating the layer with a precursor material having a concentration of about 2.5 to 5.5 mM.

[0019]

[0056] Furthermore, herein, Al 2 O3 and / or alumina, it should be noted that various ratios of aluminum and oxygen can be used to form alumina. Thus, certain embodiments described herein are Al 2 O 3 are described with reference to, but the description is not intended to define a particular ratio of aluminum in oxygen. Rather, embodiments may each include any one or more aluminum oxide compounds where the aluminum oxide ratio is AlxOy, where x can be any value, integer or non-integer, between about 1 and 100. In certain embodiments, x can be between about 1 and 3 (and again, need not be an integer). Similarly, y can be any value, integer or non-integer, between 0.1 and 100. In certain embodiments, y can be between 2 and 4 (and again, need not be an integer). Further, in various embodiments, various crystalline forms of AlxOy, such as alpha, gamma, and / or amorphous forms of alumina, may be present.

[0020]

[0057] Similarly, NiO, MoO 3 , WO 3 , and V 2 O 5The compounds can alternatively or additionally be represented as NixOy, MoxOy, WxOy, and VxOy, respectively. For each of MoxOy and WxOy, x can be any value, integer or non-integer, between about 0.5 and 100, and in certain embodiments, can be between about 0.5 and 1.5. Similarly, y can be any value, integer or non-integer, between about 1 and 100. In certain embodiments, y can be any value between about 1 and 4. For VxOy, x can be any value, integer or non-integer, between about 0.5 and 100, and in certain embodiments, can be between about 0.5 and 1.5. Similarly, y can be any value, integer or non-integer, between about 1 and 100, and in certain embodiments, it can be an integer or non-integer value between about 1 and 10. In certain embodiments, x and y can be values that are non-stoichiometric. It should be noted that any IFL material written as a stoichiometric formulation in the present disclosure can also exist in the non-stoichiometric formulations of the above examples.

[0021]

[0058] In certain embodiments, the IFL may include a titanate. A titanate according to certain embodiments may have the general formula M'TiO 3 and herein, M' can include any 2 + cations. In certain embodiments, M' can include cationic forms of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In certain embodiments, the IFL may include a single species of titanate, and in other embodiments, the IFL may include two or more different species of titanate. In one embodiment, the titanate has the formula SrTiO 3 . In other embodiments, the titanate may be represented by the formula BaTiO 3 . In yet another embodiment, the titanate may be represented by the formula CaTiO 3 .

[0022]

[0059] For purposes of illustration and not limitation, titanates have a perovskite crystal structure, and perovskite materials (e.g., methylammonium lead iodide (MAPbI 3 ) and formamidinium lead iodide (FAPbI3 Strongly seed the growth conversion process of )). Titanates generally also meet other IFL requirements such as ferroelectric behavior, sufficient charge carrier mobility, light transmissivity, matching energy levels, and high dielectric constant.

[0023]

[0060] In other embodiments, the IFL may include zirconates. In certain embodiments, the zirconate may have the general formula M’ZrO 3 and M’ may be any two + cations. In certain embodiments, M’ may include cations in the form of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In certain embodiments, the IFL may include a single species of zirconate, and in other embodiments, the IFL may include two or more different species of zirconate. In one embodiment, the zirconate is represented by the formula SrZrO 3 In another embodiment, the zirconate may be represented by the formula BaZrO 3 In yet another embodiment, the zirconate may be represented by the formula CaZrO 3

[0024]

[0061] For illustration purposes and without any limitation, zirconates (zirconates) have a perovskite crystal structure and strongly seed the growth conversion process of perovskite materials (e.g., MAPbI 3 , FAPbI 3 ). Zirconates generally also meet other IFL requirements such as ferroelectric behavior, sufficient charge carrier mobility, light transmissivity, matching energy levels, and high dielectric constant.

[0025]

[0062] In other embodiments, the IFL may include stannates. Stannates according to certain embodiments may have the general formula M’SnO 3 , or M’ 2 SnO 4 and M’ may be any two + ​It contains cations. In certain embodiments, M’ may include cations of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In certain embodiments, the IFL may include a single species of stannate, and in other embodiments, the IFL may include two or more different species of stannate. In one embodiment, the stannate has the formula SrSnO 3 as represented. In another embodiment, the stannate may be represented by the formula BaSnO 3 . In yet another embodiment, the stannate may be represented by the formula CaSnO 3 .

[0026]

[0063] For illustration purposes and without any limitation, the stannate has a perovskite crystal structure and strongly seeds the perovskite material (e.g., MAPbI 3 , FAPbI 3 ) growth conversion process. The stannate generally also meets other IFL requirements such as behavior as a ferroelectric, sufficient charge carrier mobility, light transmissivity, matching energy levels, and high dielectric constant.

[0027]

[0064] In other embodiments, the IFL may include plumbate. The plumbate according to certain embodiments may have the general formula M’PbO 3 , where M’ contains any divalent + cation. In certain embodiments, M’ may include cations of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In certain embodiments, the IFL may include a single species of plumbate, and in other embodiments, the IFL may include two or more different types of plumbate. In one embodiment, the plumbate has the formula SrPbO 3 as represented. In other embodiments, the plumbate may be represented by the formula BaPbO 3 . In still another embodiment, the plumbate may be represented by the formula CaPbO 3 . In yet another embodiment, the plumbate may be represented by the formula Pb II Pb IV O 3 .

[0028]

[0065] For illustration purposes and without any limitation, the plumbate has a perovskite crystal structure and strongly seeds the growth conversion process of perovskite materials (e.g., MAPbI 3 , FAPbI 3 ). Also, plumbates generally satisfy other IFL requirements such as behavior as a ferroelectric, sufficient charge carrier mobility, light transmissivity, matching energy levels, and high dielectric constant.

[0029]

[0066] Furthermore, in other embodiments, the IFL may include a combination of zirconates and titanates in the general formula M’[ZrxTi 1-x O 3 (where X is greater than 0 but less than 1 and M’ includes any two + cations). In certain embodiments, M’ may include cationic forms of Be, Mg, Ca, Sr, Ba, Ni, Zn, Cd, Hg, Cu, Pd, Pt, Sn, or Pb. In certain embodiments, the IFL may include a single species of zirconate, and in other embodiments, the IFL may include two or more different species of zirconates. In one embodiment, the zirconate / titanate combination is represented by the formula Pb[ZrxTi 1-x O 3 . In another embodiment, the zirconate / titanate combination is represented by the formula Pb[Zr 0.52 Ti 0.48 O 3 .

[0030]

[0067] For illustration and without any limitation, the zirconate / titanate combination has a perovskite crystal structure and strongly seeds the growth conversion process of perovskite materials (e.g., MAPbI 3 , FAPbI 3 ). The zirconate / titanate combination generally satisfies other IFL requirements such as behavior as a ferroelectric, sufficient charge carrier mobility, light transmissivity, matching energy levels, and high dielectric constant.

[0031]

[0068] In other embodiments, the IFL may include niobate. The niobate according to certain embodiments may have the general formula M’NbO 3 and M’ may include any monovalent + cation. In certain embodiments, M’ may include the cationic form of Li, Na, K, Rb, Cs, Cu, Ag, Au, Tl, ammonium, or H. In certain embodiments, the IFL may include a single species of niobate, and in other embodiments, the IFL may include two or more different species of niobate. In one embodiment, the niobate is represented by the formula LiNbO 3 . In another embodiment, the niobate may be represented by the formula NaNbO 3 . In yet another embodiment, the niobate can be represented by the formula AgNbO 3 .

[0032]

[0069] For illustration and without any limitation, niobates generally meet the IFL requirements such as piezoelectric behavior, non-linear optical susceptibility, photoelasticity, ferroelectricity, Pockels effect, sufficient charge carrier mobility, light transmissivity, aligned energy levels, and high dielectric constant.

[0033]

[0070] In one embodiment, the perovskite material device can be formulated by casting PbI 3 onto a SrTiO 2 coated ITO substrate. PbI 2 can be converted to MAPbI 3 by an immersion process. This process will be described in more detail below. The conversion of the resulting PbI 2 to MAPbI 3 is more complete (as observed by optical spectroscopy) compared to the preparation of substrates that do not include SrTiO 3 .

[0034]

[0071] The interfacial materials described herein may further include a doped composition. To modify the properties (e.g., electrical, optical, mechanical) of the interfacial materials, stoichiometric or non-stoichiometric materials may be doped in an amount ranging from 1 ppb% to 50 mol% of one or more elements (e.g., Na, Y, Mg, N, P). Some examples of interfacial materials include NiO, TiO 2 , SrTiO 3 , Al 2 O 3 , ZrO 2 , WO 3 , V 2 O 5 , MO 3 , ZnO, graphene, and carbon black. Examples of possible dopants for these interfacial materials include Li, Na, Be, Mg, Ca, Sr, Ba, Sc, Y, Nb, Ti, Fe, Co, Ni, Cu, Ga, Sn, In, B, N, P, C, S, As, halides, pseudohalides (e.g., cyanides, cyanates, isocyanates, fulminates, thiocyanates, isothiocyanates, azides, tetracarbonylcobaltates, carbamoyldicyanomethanides, dicyanonitrosomethanides, dicyanamide, and tricyanomethanides), and Al in any of its oxidation states. Here, the reference to a doped interfacial material is not intended to limit the ratio of components in the interfacial material compound.

[0035]

[0072] In certain embodiments, a plurality of IFLs made from different materials can be arranged adjacent to each other to form a composite IFL. This configuration may include two different IFLs, three different IFLs, or even more different IFLs. The resulting multilayer IFL or composite IFL can be used in place of a single-material IFL. For example, the composite IFL can use any of the IFLs shown in the example of FIG. 2, such as IFL3903, IFL3905, IFL3907, IFL3909, or IFL3911. The composite IFL is different from a single-material IFL, but an assembly of perovskite material PV cells with a multilayer IFL is not substantially different from an assembly of perovskite material PV cells with only a single-material IFL.

[0036]

[0073] Generally, the composite IFL can be made suitable for the IFL using any of the materials described herein. In one embodiment, the IFL is Al 2 O 3 layer and a layer of ZnO or M:ZnO (doped ZnO, e.g., Be:ZnO, Mg:ZnO, Ca:ZnO, Sr:ZnO, Ba:ZnO, Sc:ZnO, Y:ZnO, Nb:ZnO). In one embodiment, the IFL is ZrO 2 layer and a layer of ZnO or M:ZnO. In certain embodiments, the IFL includes a plurality of layers. In certain embodiments, the multilayer IFL generally has a conductor layer, a dielectric layer, and a semiconductor layer. In certain embodiments, the layers can, for example, repeat a conductor layer, a dielectric layer, a semiconductor layer, a dielectric layer, and a semiconductor layer. Examples of multilayer IFLs include an ITO layer, an Al 2 O 3 layer, a ZnO layer, an IFL having a second Al 2 O 3 layer, an ITO layer, an Al 2 O 3 layer, a ZnO layer, an IFL having a second Al 2 O 3 layer, a second ZnO layer, an ITO layer, an Al 2 O 3 layer, a ZnO layer, an IFL having a second Al 2 O 3 layer, a second ZnO layer, and a third Al 2 O 3 layer, an IFL having the number of layers necessary to achieve the desired performance characteristics. As noted above, the reference to a specific stoichiometric ratio is not intended to limit the ratio of components in the IFL layers according to various embodiments.

[0037]

[0074] When two or more adjacent IFLs are arranged as a composite IFL, the attributes of each IFL material may be utilized in a perovskite material PV cell that exceeds a single IFL. For example, in an architecture having an ITO layer, an Al 2 O 3 layer, and a ZnO layer, the ITO is a conductive electrode, and the Al 2O 3 is a dielectric material, ZnO is an n-type semiconductor, and ZnO acts as an electron acceptor with good electron transport properties (e.g., mobility). Further, Al 2 O 3 is a physically robust material that has excellent adhesion to ITO, homogenizes the surface by capping surface defects (e.g., charge traps), suppresses dark current, and thereby improves the characteristics of the device diode.

[0038]

[0075] Furthermore, a certain perovskite material PV cell may include a so-called "tandem" PV cell having two or more perovskite photoactive layers. For example, both the photoactive materials 3908 and 3906 in FIG. 2 may be perovskite materials. In the tandem PV cell, an interface layer between two photoactive layers, such as the IFL 3907 (i.e., recombination layer) in FIG. 2, may include a multilayer or composite IFL. In certain embodiments, the layer sandwiched between two photoactive layers of a tandem PV device may include an electrode layer.

[0039]

[0076] A tandem PV device may include the following layers described in that order or the reverse order: a first substrate, a first electrode, a first interface layer, a first perovskite material, a second interface layer, a second electrode, a third interface layer, a second perovskite material, a fourth interface layer, and a third electrode. In certain embodiments, the first and third interface layers may be hole transport interface layers, and the second and fourth interface layers may be electron transport interface layers. In other embodiments, the first and third interface layers may be electron transport interface layers, and the second and fourth interface layers may be hole transport interface layers. In still other embodiments, the first and fourth interface layers may be hole transport interface layers, and the second and third interface layers may be electron transport interface layers. In other embodiments, the first and fourth interface layers may be electron transport interface layers, and the second and third interface layers may be hole transport interface layers. In a tandem PV device, the first and second perovskite materials may have different band gaps. In certain embodiments, the first perovskite material is formamidinium lead bromide (FAPbBr 3) and the second perovskite material may be formamidinium lead iodide (FAPbI 3 ). In other embodiments, the first perovskite material may be methylammonium lead bromide (MAPbBr 3 ), and the second perovskite material may be formamidinium lead iodide (FAPbI 3 ). In other embodiments, the first perovskite material may be methylammonium lead bromide (MAPbBr 3 ), and the second perovskite material may be methylammonium lead iodide (MAPbI 3 ).

[0040]

[0077] Perovskite material The perovskite material may be incorporated into one or more aspects of a PV or other device. The perovskite material according to certain embodiments may have the general formula CwMyXz, where C includes one or more cations (e.g., amines, ammonium, phosphonium, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds), M includes one or more metals (examples including Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), X includes one or more anions, and w, y, and z represent real numbers from 1 to 20. In certain embodiments, C may include one or more organic cations. In certain embodiments, each organic cation C may be larger than each metal M, and each anion X may be capable of binding to both the cation C and the metal M. In certain embodiments, the perovskite material may have the formula CMX 3 .

[0041]

[0078] In certain embodiments, C is ammonium, with the general formula [NR4] +may contain an organic cation, where the R groups may be the same or different. Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; any alkane, alkene, or alkyne CxHy (where x = 1 to 20, y = 1 to 42, cyclic, branched, or linear); alkyl halide CxHyXz, (where x = 1 to 20, y = 0 to 42, z = 1 to 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., pyridine, pyrrole, pyrrolidine, piperidine, tetrahydroquinoline); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid) including α, β, γ and higher derivatives; any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (where x = 0 to 20, y = 1 to 42), but are not limited thereto.

[0042]

[0079] In one embodiment, C is formamidinium, of the general formula [R2NCRNR2] +may contain the organic cation, where the R group is the same or different groups (e.g., acetic acid, propanoic acid). Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; any alkane, alkene, or alkyne CxHy (where x = 1 to 20, y = 1 to 42, cyclic, branched, or straight-chain); alkyl halide CxHyXz, (where x = 1 to 20, y = 0 to 42, z = 1 to 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., imidazole, benzimidazole, (azolidinylidene methyl)pyrrolidine, triazole); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid containing α, β, γ and more derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid); any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (where x = 0 to 20, y = 1 to 42), but are not limited to these.

[0043]

[0080]

Chemical formula

[0044]

Chemical formula

[0045]

[0081] ​In one embodiment, C may include a guanidinium, general formula [(R 2 N) 2 C=NR 2 + organic cation, where the R groups may be the same or different. Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; any alkane, alkene, or alkyne CxHy (x = 1 to 20, y = 1 to 42, cyclic, branched, or straight-chain); alkyl halide CxHyXz, (where x = 1 to 20, y = 0 to 42, z = 1 to 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., octahydropyrimido[1,2-a]pyrimidine, pyrimido[1,2-a]pyrimidine, hexahydroimidazo[1,2-a]imidazole, hexahydroimine-2-imine); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (phosphoric acid); any boron-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid) including α, β, γ and higher derivatives; any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (where x = 0 to 20, y = 1 to 42), but are not limited thereto.

[0046]

[0082]

Chemical formula

[0047]

Chemical formula

[0048]

[0083] In one embodiment, C may include an ethylenetetramine cation, i.e., a general formula [(R 2 N) 2 C=C(NR 2 ) 2 + organic cation, where the R groups may be the same or different groups. Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; any alkane, alkene, or alkyne CxHy (x = 1 to 20, y = 1 to 42, cyclic, branched, or straight-chain); alkyl halide CxHyXz, (where x = 1 to 20, y = 0 to 42, z = 1 to 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., 2-hexahydropyrimidine, octahydropyrazino[2,3-b]pyrazine, pyrazino[2,3-b]pyrazine, quinoxaline); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (phosphoric acid); any boron-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid) including α, β, γ and higher derivatives; any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (where x = 0 to 20, y = 1 to 42), but are not limited thereto.

[0049]

[0084]

Chemical formula

[0050]

Chemical Formula

[0051]

[0085] In certain embodiments, C may include an imidazolium cation, an aromatic cyclic organic cation of the general formula [CRNRCRNRCR] + where the R groups may be the same or different. Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; alkanes, alkenes or alkynes CxHy (x = 1 - 20, y = 1 - 42, cyclic, branched or straight-chain); haloalkyls, alkyl halides CxHyXz, (where x = 1 - 20, y = 0 - 42, z = 1 - 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., 2-hexahydropyrimidine, octahydropyrazino[2,3-b]pyrazine, pyrazino[2,3-b]pyrazine, quinoxaline[2,3-b]quinoxaline); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (phosphoric acid); any boron-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid) including α, β, γ and higher derivatives; any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (where x = 0 - 20, y = 1 - 42), but are not limited thereto. ​

[0052]

[0086] In one embodiment, C may include a pyridinium cation, an aromatic cyclic organic cation of the general formula [CRCRCRCRNR] + wherein the R groups may be the same or different. Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; alkanes, alkenes or alkynes CxHy (x = 1 to 20, y = 1 to 42, cyclic, branched or straight chain); halogenated alkyls, alkyl halides CxHyXz, (wherein x = 1 to 20, y = 0 to 42, z = 1 to 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., 2-hexahydropyrimidine, octahydropyrazino[2,3-b]pyrazine, pyrazino[2,3-b]pyrazine, quinoxaline[2,3-b]quinoxaline); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (phosphoric acid); any boron-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid including α, β, γ and higher derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid); any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (wherein x = 0 to 20, y = 1 to 42), but are not limited thereto.

[0053]

Chemical formula

[0087] In certain embodiments, X may include one or more halides. In certain embodiments, X may alternatively or instead include a Group 16 anion. In certain embodiments, the Group 16 anion may be an oxide, sulfide, selenide, or telluride. In certain embodiments, X may alternatively or instead include one or more pseudohalides (e.g., cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide, and tricyanomethanide).

[0054]

[0088] In one embodiment, the perovskite material may include the empirical formula CMX 3 wherein C includes one or more of the above cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds, M includes one or more metals (examples including Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X includes one or more of the above anions.

[0055]

[0089] In another embodiment, the perovskite material may include the empirical formula C’MX 2 X 6 wherein C’ includes a cation having a 2 + charge and including one or more of the above cations, diammonium butane, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds, M includes one or more metals (examples including Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X includes one or more of the above anions.

[0056]

[0090] In another embodiment, the perovskite material may include the empirical formula C’MX 4may include, where C’ includes one or more of the above cations, diammonium butane, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds2 + and includes cations having a charge of 2, M includes one or more metals (examples include Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X includes one or more of the above anions. In such embodiments, the perovskite material may have a two-dimensional structure.

[0057]

[0091] In one embodiment, the perovskite material has the empirical formula C 3 M 2 X 9 and may include, where C includes one or more of the above cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds, M includes one or more metals (examples include Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X includes one or more of the above anions.

[0058]

[0092] In one embodiment, the perovskite material can have the empirical formula CM 2 X 7 and includes, where C includes one or more of the above cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds, M includes one or more metals (including, for example, Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zrn), and X includes one or more of the above anions.

[0059]

[0093] In one embodiment, the perovskite material has the empirical formula C 2 MX 4may include, where C includes one or more of the above cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds, M includes one or more metals (including examples such as Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X includes one or more of the above anions.

[0060]

[0094] The perovskite material may also be a mixed ion formulation in which C, M, or X includes two or more species, for example, Cs 0.1 FA 0.9 Pb(I 0.9 Cl 0.1 ) 3 ; Rb 0.1 FA 0.9 Pb(I 0.9 Cl 0.1 ) 3 Cs 0.1 FA 0.9 PbI 3 ; FAPb 0.5 Sn 0.5 I 3 ; FA 0.83 Cs 0.17 Pb(I 0.6 Br 0.4 ) 3 ; FA 0.83 Cs 0.12 Rb 0.05 Pb(I 0.6 Br 0.4 ) 3 and FA 0.85 MA 0.15 Pb(I 0.85 Br 0.15 ) 3 may be included.

[0061]

[0095] Composite perovskite material device design In one embodiment, the present disclosure can provide a composite design of PV and other similar devices (e.g., batteries, hybrid PV cells, FETs, LEDs, nonlinear optical systems (NLOs), waveguides, etc.) that includes one or more perovskite materials. For example, the one or more perovskite materials can function as either or both of the first and second active materials of one embodiment (e.g., active materials 3906a and 3908a of FIG. 3). More generally, one embodiment of the present disclosure provides a PV or other device having an active layer that includes one or more perovskite materials. In such an embodiment, the perovskite material (i.e., a material that includes any one or more perovskite materials) can be used in active layers of various architectures. Further, the perovskite material can function as any one or more of the components of the active layer (e.g., charge transport materials, mesoporous materials, photoactive materials, and / or interfacial materials), each of which will be described in more detail below. In one embodiment, the same perovskite material can perform multiple such functions, while in other embodiments, multiple perovskite materials can be included in the device, and each perovskite material can have one or more of the above functions. In one embodiment, regardless of what function the perovskite material performs, it can be prepared and / or present in the device in various states. For example, in one embodiment, it can be substantially solid. A solution or suspension can be coated onto (e.g., on another component of the device such as a mesoporous layer, interfacial layer, charge transport layer, photoactive layer, or other layer, and / or on an electrode) or otherwise deposited within the device. In one embodiment, the perovskite material can be formed in situ on the surface of another component of the device (e.g., by vapor deposition as a thin film solid). Any other suitable means for forming a layer that includes the perovskite material can be used.

[0062]

[0096] Generally, a perovskite material device can include a first electrode, a second electrode, and an active layer including a perovskite material, and the active layer is at least partially disposed between the first electrode and the second electrode. In certain embodiments, the first electrode can be one of an anode and a cathode, and the second electrode can be the other of the anode and the cathode. The active layer according to certain embodiments can include any one or more of an active layer component including a charge transport material, a liquid electrolyte, a mesoporous material, a photoactive material (e.g., a dye, silicon, cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, gallium arsenide, indium germanium phosphide, a semiconductor polymer, and other photoactive materials), and an interfacial material. One or more of these active layer components can include one or more perovskite materials. In certain embodiments, some or all of the active layer components can be disposed as sub-layers, either wholly or in part. For example, the active layer can include one or more of an interfacial layer including an interfacial material, a mesoporous layer including a mesoporous material, and a charge transport layer including a charge transport material. Further, the interfacial layer can be included between any two or more other layers of the active layer and / or between the active layer component and the electrode in certain embodiments. References to layers herein can mean the placement during the construction of the device, by reference to the final placement (e.g., the substantially discrete portions of each material that can be separately defined within the device) and / or references to layers, although the materials within each layer may subsequently be intermixed. In certain embodiments, the layers can be discrete and include substantially adjacent materials (e.g., the layers can be like those schematically shown in FIG. 2).

[0063]

[0097] In certain embodiments, the perovskite material device can be a field effect transistor (FET). The FET perovskite material device can include a source electrode, a drain electrode, a gate electrode, a dielectric layer, and a semiconductor layer. In certain embodiments, the semiconductor layer of the FET perovskite material device can be a perovskite material.

[0064]

[0098] A perovskite material device according to an embodiment may optionally include one or more substrates. In some embodiments, either or both of the first and second electrodes may be coated or otherwise disposed on the substrate such that the electrodes are substantially disposed between the substrate and the active layer. The materials of the device's composition (e.g., substrate, electrodes, active layer, and / or active layer components) may be either rigid or flexible, in whole or in part, in various embodiments. In some embodiments, the electrode functions as the substrate, thereby eliminating the need for a separate substrate.

[0065]

[0099] Furthermore, a perovskite material device according to an embodiment may optionally include an anti-reflection layer or anti-reflection coating. Additionally, the perovskite material device may include any one or more of the above additives with respect to certain embodiments of the present disclosure.

[0066]

[0100] A description of the various materials that may be included in the perovskite material device is given in part with reference to FIG. 2. FIG. 2 is a schematic diagram of a perovskite material device 3900 according to an embodiment. Although the various components of device 3900 are shown as discrete layers including adjacent materials, it should be understood that FIG. 2 is a schematic diagram, and thus embodiments according thereto may include such discrete layers and / or substantially mixed non-adjacent layers consistent with the use of "layers" described above herein. Device 3900 includes first and second substrates 3901 and 3913. First electrode 3902 is disposed on the inner surface of first substrate 3901, and second electrode 3912 is disposed on the inner surface of second substrate 3913. Active layer 3950 is sandwiched between two electrodes 3902 and 3912. Active layer 3950 includes a mesoporous layer 3904, first and second photoactive materials 3906 and 3908, a charge transport layer 3910, and an interface layer. Further, FIG. 2 illustrates an exemplary device 3900 according to an embodiment in which sub-layers of active layer 3950 are separated by interface layers, and the interface layers are disposed on each of electrodes 3902 and 3912. In particular, second, third, and fourth interface layers 3905, 3907, and 3909 are each disposed between mesoporous layer 3904, first photoactive material 3906, second photoactive material 3908, and charge transport layer 3910, respectively. First and fifth interface layers 3903 and 3911 are each disposed between (i) first electrode 3902 and mesoporous layer 3904, and (ii) charge transport layer 3910 and second electrode 3912. Thus, the architecture of the exemplary device shown in FIG. 2 can be characterized as substrate - electrode - active layer - electrode - substrate. The architecture of active layer 3950 can be characterized as interface layer - mesoporous layer - interface layer - photoactive material - interface layer - photoactive material - interface layer - charge transport layer - interface layer. As noted above, in some embodiments, interface layers need not be present, or one or more interface layers may be included only between, but not all of, the components of a particular active layer and / or the components of the device.

[0067]

[0101] Substrates, such as either or both of the first and second substrates 3901 and 3913, may be either rigid or flexible. If two substrates are included, at least one should be transparent or translucent to electromagnetic (EM) radiation (e.g., ultraviolet, visible light, or infrared). If one substrate is included, a portion of the device may be similarly transparent or translucent, but need not be, as long as EM radiation can reach the active layer 3950. Suitable substrate materials include glass, sapphire, magnesium oxide (MgO), mica, polymers (e.g., PEN, PET, PEG, polyolefin, polypropylene, polyethylene, polycarbonate, PMMA, polyamide, vinyl, Kapton), ceramics, carbon, composites (e.g., glass fiber, Kevlar, carbon fiber), fabrics (e.g., cotton, nylon, silk, wool), wood, drywall, tiles (e.g., ceramic, composite, or clay), metals, steel, silver, gold, aluminum, magnesium, concrete, and one or more of combinations thereof.

[0068]

[0102] As described above, the electrode (e.g., one of the electrodes 3902 and 3912 in FIG. 2) may be either an anode or a cathode. In certain embodiments, one electrode may function as a cathode and the other electrode may function as an anode. One or both of the electrodes 3902 and 3912 may be coupled to a lead, cable, wire, or other means that enables charge transport to and / or from the device 3900. The electrode can be composed of any conductive material, and at least one electrode should be transparent or translucent to EM radiation and / or should be arranged such that the EM radiation can contact at least a portion of the active layer 3950. Suitable electrode materials may include any one or more of indium tin oxide or tin-doped indium oxide (ITO); fluorine-doped tin oxide (FTO); cadmium oxide (CdO); zinc indium tin oxide (ZITO); aluminum zinc oxide (AZO); aluminum (Al); gold (Au); silver (Ag); calcium (Ca); chromium (Cr); copper (Cu); magnesium (Mg); titanium (Ti); steel; carbon (and its allotropes); doped carbon (e.g., nitrogen-doped); nanoparticles having a core-shell structure (e.g., a silicon-carbon core-shell structure); and combinations thereof.

[0069]

[0103] The mesoporous material (e.g., the material included in the mesoporous layer 3904 of FIG. 2) may include any pore-containing material. In certain embodiments, the pore diameter may range from about 1 to about 100 nm, and in other embodiments, the pore diameter may range from about 2 to about 50 nm. Suitable mesoporous materials include any interfacial material and / or mesoporous material described elsewhere herein; aluminum (Al); bismuth (Bi); cerium (Ce); hafnium (Hf); indium (In); molybdenum (Mo); niobium (Nb); nickel (Ni); silicon (Si); titanium (Ti); vanadium (V); zinc (Zn); zirconium (Zr); any one or more oxides of the foregoing metals (e.g., alumina, ceria, titania, zinc oxide, zirconia, etc.); any one or more sulfides of the foregoing metals; any one or more nitrides of the foregoing metals; and any one or more of combinations thereof. In certain embodiments, any material disclosed herein as an IFL may be a mesoporous material. In other embodiments, the apparatus shown in FIG. 2 may not include a mesoporous material layer and may include only a non-mesoporous thin film or “compact” IFL.

[0070]

[0104] The photoactive material (e.g., the first or second photoactive material 3906 or 3908 in FIG. 2) may include any one or more of the following photoactive compounds: silicon (e.g., polycrystalline silicon, single-crystalline silicon, or amorphous silicon), cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, copper indium selenide, copper zinc tin sulfide, gallium arsenide, germanium, indium germanium phosphide, indium phosphide, one or more semiconductor polymers (e.g., polythiophene) (3-hexylthiophene) and its derivatives, or P3HT; carbazole-based copolymers such as polyheptadecanylcarbazole dithienylbenzothiadiazole and its derivatives (e.g., PCDTBT); other polymers such as polycyclopentadithiophene benzothiadiazole and its derivatives (e.g., PCPDTBT) and polybenzodithiophenyl thienothiophenediyl and its derivatives (e.g., PTB6, PTB7, PTB7-th, PCE-10); poly(triarylamine) compounds and their derivatives; polyphenylene vinylene and its derivatives (e.g., MDMO-PPV, MEH-PPV), and combinations thereof.

[0071]

[0105] In some embodiments, the photoactive material may alternatively or additionally include a dye (e.g., N719, N3, other ruthenium-based dyes). In some embodiments, the dye (of any composition) may be coated on another layer (e.g., a mesoporous layer and / or an interfacial layer). In some embodiments, the photoactive material may include one or more perovskite materials. The photoactive material containing perovskite material may be a solid, or in some embodiments, may be in the form of a suspension or solution containing a perovskite material and a dye. The solution or suspension may be coated on other device components in the same manner as other dyes. In some embodiments, the solid perovskite-containing material may be deposited by any suitable means (e.g., vapor deposition, solution deposition, direct placement of a solid material). Devices according to various embodiments may include one, two, three, or more photoactive compounds (e.g., one, two, three, or more perovskite materials, dyes, or combinations thereof). In some embodiments including multiple dyes or other photoactive materials, each of the two or more dyes or other photoactive materials may be separated by one or more interfacial layers. In some embodiments, the multiple dyes and / or photoactive compounds may be at least partially mixed.

[0072]

[0106] The charge transport material (e.g., the charge transport material of the charge transport layer 3910 in FIG. 2) may include a solid charge transport material (i.e., a so-called solid electrolyte), or may include a liquid electrolyte and / or an ionic liquid. Any of a liquid electrolyte, an ionic liquid, and a solid charge transport material may be referred to as a charge transport material. As used herein, "charge transport material" refers to any material, solid, liquid, or otherwise, that can collect and / or transport charge carriers. For example, in a PV device according to some embodiments, the charge transport material can transport charge carriers to the electrodes. The charge carriers may include holes (transport of which may cause the charge transport material to be appropriately designated as a "hole transport material") and electrons. The holes are transported towards the anode and the electrons are transported towards the cathode, which is due to the arrangement of the charge transport material with respect to either the cathode or the anode of the PV or other device. Suitable examples of charge transport materials according to some embodiments are perovskite materials; I- / I 3 - ; Co complex; polythiophene (e.g., poly(3-hexylthiophene) and its derivatives, or P3HT); carbazole-based copolymers such as polyheptadecanylcarbazole dithienylbenzothiadiazole and its derivatives (e.g., PCDTBT); polycyclopentadithiophene benzothiadiazole and its derivatives (e.g., PCTBPDT), polybenzodithiophenyl thienothiophenediyl and its derivatives (e.g., PTB6, PTB7, PTB7-th, PCE-10); poly(triarylamine) compounds and their derivatives (e.g., PTAA); Spiro-OMeTAD; polyphenylene vinylene and its derivatives (e.g., MDMO-PV, MEH-PV); fullerene and / or fullerene derivatives (e.g., C60, PCBM); carbon nanotubes; graphite; graphene; carbon black; amorphous carbon; vitreous carbon; carbon fiber; and any one or more combinations thereof may be included. In certain embodiments, the charge transport material may include any solid or liquid material that can collect charge carriers (electrons or holes) and / or transport charge carriers. Thus, the charge transport material of certain embodiments may be an n-type or p-type active, bipolar, and / or intrinsic semiconductor material. The charge transport material may be disposed proximate to one of the electrodes of the device. In certain embodiments, it may be disposed adjacent to the electrode, but in other embodiments, an interfacial layer may be disposed between the charge transport material and the electrode (e.g., having a fifth interfacial layer 3911 as shown in FIG. 2). In certain embodiments, the type of charge transport material may be selected based on the electrode to which it is proximate. For example, if the charge transport material collects and / or transports holes, it may be proximate to the anode to transport holes to the anode. However, the charge transport material may instead be disposed proximate to the cathode and selected or configured to transport electrons to the cathode.

[0073]

[0107] As described above, the devices according to various embodiments may optionally include an interfacial layer between any two other layers and / or materials, although in some embodiments, the devices may not include any interfacial layer. Thus, for example, a perovskite material device may include zero, 1, 2, 3, 4, 5, or more interfacial layers (e.g., the exemplary device of FIG. 2 includes five interfacial layers 3903, 3905, 3907, 3909, and 3911). The interfacial layer may include a thin film interfacial layer according to the above embodiments herein (e.g., including alumina and / or other metal oxide particles, and / or a titanium oxide / metal oxide bilayer, and / or other compounds according to the thin film interfacial layers described elsewhere herein). An interfacial layer according to some embodiments may include any suitable material for enhancing charge transport and / or collection between two layers or materials, and may serve to prevent or reduce the likelihood of charge recombination after charge has been transported from one of the materials adjacent to the interfacial layer. Suitable interfacial materials include any mesoporous materials and / or interfacial materials described elsewhere herein; Ag, Al, Au, B, Bi, Ca, Cd, Ce, Co, Cu, Fe, Ga, Ge, H, In, Mg, Mn, Mo, Nb, Ni, Pt, Sb, Sc, Si, Sn, Ta, Ti, V, W, Y, Zn, Zr, carbides of any of the foregoing metals (e.g., SiC, Fe 3 C, WC); silicides of any of the foregoing metals (e.g., Mg 2 Si, SrSi 2 、Sn 2 Si); oxides of any of the foregoing metals (e.g., alumina, silica, titania, SnO 2 、ZnO; sulfides of any of the foregoing metals (e.g., CdS, MoS 2 、SnS 2 ); nitrides of any of the foregoing metals (e.g., Mg 3 N 2 、TiN, BN, Si 3 N 4 ); selenides of any of the foregoing metals (e.g., CdSe, FeSe 2 、ZnSe), tellurides of any of the foregoing metals (e.g., CdTe, TiTe 2, ZnTe), any phosphide of said metal (e.g., InP, GaP), any arsenide of said metal (e.g., CoAs 3 , GaAs, InGaAs, NiAs), any antimonide of said metal (e.g., AlSb, GaSb, InSb), any halide of said metal (e.g., CuCl) CuI, BiI 3 ; any pseudohalide of said metal (e.g., CuSCN, AuCN 2 ); any carbonate of said metal (e.g., CaCO 3 , Ce 2 (CO 3 ) 3 ); functionalized or non-functionalized alkylsilyl groups; graphite; graphene; fullerenes; carbon nanotubes; any mesoporous material and / or interfacial material described elsewhere herein; and any combination thereof (in certain embodiments, including two, three or more layers of composite materials). In certain examples, the interfacial layer may comprise a perovskite material. Further, the interfacial layer may include a doped embodiment of any interfacial material described herein (e.g., Y-doped ZnO, N-doped single-walled carbon nanotubes). The interfacial layer may also include a compound comprising three of the above materials (e.g., CuTiO 3 , Zn 2 SnO 4 ) or a compound comprising four of the above materials (e.g., CoNiZnO).

[0074]

[0108] As an example, FIG. 3 shows an embodiment of a perovskite material device 3900a having a structure similar to the perovskite material device 3900 shown in FIG. 2. FIG. 3 is a stylized view of a perovskite material device 3900a according to an embodiment. Although the various components of device 3900a are shown as discrete layers including adjacent materials, it should be understood that FIG. 3 is a stylized view. Accordingly, embodiments thereof may include such discrete layers, and / or substantially mixed non-adjacent layers, consistent with the use of the above “layers” herein. FIG. 3 includes active layers 3906a and 3908a. In certain embodiments, one or both of active layers 3906a and 3908a may include any of the perovskite photoactive materials described above with respect to FIG. 2. In other embodiments, one or both of active layers 3906a and 3908a may include any photoactive material described herein, such as thin film semiconductors (e.g., CdTe, CZTS, CIGS), photoactive polymers, dye-sensitized photoactive materials, fullerenes, low molecular weight photoactive materials, and crystalline and polycrystalline semiconductor materials (e.g., silicon, GaAs, InP, Ge). In still other embodiments, one or both of active layers 3906a and 3908a may include a light emitting diode (LED), a field effect transistor (FET), a thin film battery layer, or a combination thereof. In a low molecular weight photoactive material embodiment, one of active layers 3906a and 3908a may include a photoactive material and the other may include a light emitting diode (LED), a field effect transistor (FET), a thin film battery layer, or a combination thereof. For example, active layer 3908a may include a perovskite material photoactive layer and active layer 3906b may include a field effect transistor layer. Other layers shown in FIG. 3, such as layers 3901a, 3902a, 3903a, 3904a, 3905a, 3907a (i.e., recombination layer), 3909a, 3910a, 3911a, 3912a, and 3913a may be similar to the corresponding layers as described herein with respect to FIG. 2.

[0075]

[0109] Furthermore, in certain embodiments, the perovskite material may have three or more active layers. As an example, FIG. 4 shows an embodiment of a perovskite material device 3900b having a structure similar to the perovskite material device 3900 shown in FIG. 2. FIG. 3 is a schematic diagram of a perovskite material device 3900b according to certain embodiments. Although the various components of device 3900b are illustrated as discrete layers including adjacent materials, it should be understood that FIG. 4 is a schematic diagram. Accordingly, embodiments thereof may include such discrete layers and / or substantially mixed non-adjacent layers that are consistent with the use of the "layers" described above herein. FIG. 4 includes active layers 3904b, 3906b, and 3908b. In certain embodiments, one or more of active layers 3904b, 3906b, and 3908b may include any of the perovskite photoactive materials described above with respect to FIG. 2. In other embodiments, one or more of active layers 3904b, 3906b, and 3908b may include any photoactive material described herein, such as thin film semiconductors (e.g., CdTe, CZTS, CIGS), photoactive polymers, dye-sensitized photoactive materials, fullerenes, small molecule photoactive materials, and crystalline and polycrystalline semiconductor materials (e.g., silicon, GaAs, InP, Ge). In still other embodiments, one or more of active layers 3904b, 3906b, and 3908b may include a light emitting diode (LED), a field effect transistor (FET), a thin film battery layer, or a combination thereof. In embodiments, one or more of the active layers of active layers 3904b, 3906b, and 3908b may include a photoactive material, while the other may include a light emitting diode (LED), a field effect transistor (FET), a thin film battery layer, or a combination thereof. For example, both active layers 3908a and 3906b may include perovskite material photoactive layers, and active layer 3904b may include a field effect transistor layer. Other layers shown in FIG. 3, such as layers 3901b, 3902b, 3903b, 3904b, 3905b (i.e., recombination layer), 3907b (i.e., recombination layer), 3909b, 3910b, 3911b, 3912b, and 3913b, may be similar to the corresponding layers as described herein with respect to FIG. 2.

[0076]

[0110] Further, more specific, exemplary embodiments of the perovskite device are described with respect to a further stylized depiction of the exemplary device. The stylized nature of these depictions, FIGS. 1-4, is not, in like manner, in one embodiment, intended to limit the types of devices that may be constituted by any one or more of FIGS. 1-4. That is, it is constructed in accordance with the architecture of any one or more of FIGS. 1-4. FIGS. 1-4 can be adapted to provide other BHJ, battery, FET, hybrid PV cells, serial multi-cell PV, parallel multi-cell PV, and other similar devices of other embodiments of the present disclosure by any suitable means (including both those explicitly described elsewhere in this specification and other suitable means that will be apparent to those skilled in the art having the benefit of the present disclosure).

[0077]

[0111] Formation of the perovskite material active layer As described above, in one embodiment, the perovskite material in the active layer is CMX 3-y X’ y (0≧y≧3), where C includes one or more cations (e.g., amine, ammonium, group 1 metal, group 2 metal, formamidinium, guanidinium, tetramine, phosphonium, imidazolium, and / or other cations or cation-like compounds), M includes one or more metals (e.g., Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr), and X and X’ include one or more anions. In one embodiment, the perovskite material may include CPbI 3-y Cl y . In certain embodiments, the perovskite material can be deposited as an active layer on a substrate layer using the processes described below, for example, by drop casting, spin casting, slot die printing, screen printing, or inkjet printing.

[0078]

[0112] First, a precursor ink of lead halide is formed. The amount of lead halide can be masked in a clean and dry container in a controlled atmosphere environment (for example, an environment without air can be achieved by a controlled atmosphere box equipped with a port hole including gloves for handling substances). Suitable lead halides include, but are not limited to, lead(II) iodide, lead(II) bromide, lead(II) chloride, and lead(II) fluoride. The lead halide may be composed of a single lead halide species or may be composed of a mixture of lead halides in an exact ratio. In certain embodiments, the lead halide mixture may be composed of any binary, ternary, or quaternary ratio of 0.001 to 100 mol% iodide, bromide, chloride, or fluoride. In one embodiment, the lead halide mixture may contain lead(II) chloride and lead(II) iodide in a molar ratio of about 10:90. In other embodiments, the lead halide mixture may contain lead(II) chloride and lead(II) iodide in a molar ratio of about 5:95, about 7.5:92.5, or about 15:85.

[0079]

[0113] Alternatively, other lead salt precursors can be used, either together with or in place of the lead halide salt, to form the precursor ink. Suitable precursor salts may include any combination of lead(II) or lead(IV) with the following anions: nitrate, nitrite, carboxylate, acetate, acetylacetonato, formate, oxalate, sulfate, sulfite, thiosulfate, phosphate, tetrafluoroborate, hexafluorophosphate, tetra(perfluorophenyl)borate, hydride, oxide, peroxide, hydroxide, arsenate, arsenite, perchlorate, carbonate, bicarbonate, chromate, dichromate, iodate, bromate, chlorate, chlorite, hypochlorite, hypobromite, cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide and tricyanomethanide, tricyanomethane, amide, and permanganate.

[0080]

[0114] The precursor ink may further contain, as the salt of the anion, a lead (II) salt or a lead (IV) salt having a molar ratio of 0 to 100% with respect to the following metal ions Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr.

[0081]

[0115] Next, a solvent can be added to the container to dissolve the lead solid and form a lead halide precursor ink. Suitable solvents include, but are not limited to, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the lead solid is dissolved in dry dimethylformamide (DMF). The lead solid can be dissolved at a temperature of about 20 to 150 °C. In one embodiment, the lead solid is dissolved at about 85 °C and can be dissolved only as much as necessary to form a solution, which may occur up to about 72 hours. The resulting solution forms the basis of the lead halide precursor ink. In certain embodiments, the lead halide concentration of the lead halide precursor ink may be from about 0.001 M to about 10 M. In one embodiment, the lead halide concentration of the lead halide precursor ink may be about 1 M.

[0082]

[0116] In some cases, specific additives can be added to the lead halide precursor ink to affect the final perovskite crystallinity and stability. In certain embodiments, the lead halide precursor ink may further comprise an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrogen halide (e.g., 5-aminovalerate hydrochloride), an IFL surface modification (SAM) agent (e.g., those described above in the specification), or combinations thereof. Suitable amino acids for the lead halide precursor ink include, but are not limited to, α-amino acids, β-amino acids, γ-amino acids, δ-amino acids, and any combination thereof. In one embodiment, formamidinium chloride may be added to the lead halide precursor ink. In other embodiments, halides of any of the cations described above in this specification can be used. In certain embodiments, for example, a combination of additives can be added to the lead halide precursor ink, including a combination of formamidinium chloride and 5-aminovalerate chloride.

[0083]

[0117] For purposes of explanation, and without limiting the present disclosure to any particular theory of mechanism, formamidinium chloride and 5-aminovaleric acid have been found to improve the stability of perovskite PV devices when used as additives or counter cations in the one-step fabrication of perovskite devices. Also, chloride has been found to improve the performance of two-step perovskite PV devices when added to the PbI 2 precursor solution in the form of PbCl 2 . The two-step perovskite thin film deposition process can be improved by directly adding formamidinium chloride and / or 5-aminovalerate hydrochloride to the lead halide precursor solution (e.g., PbI 2 ), and it has been found that the advantages of both can be utilized with a single material. Similarly, other perovskite film formation processes can be improved by adding formamidinium chloride, 5-aminovalerate chloride, or PbCl 2 to the lead halide precursor solution.

[0084]

[0118] An additive containing formamidinium chloride and / or 5-aminovaleric acid hydrochloride. Depending on the desired properties of the obtained perovskite material, it can be added to the lead halide precursor ink at various concentrations. In one embodiment, the additive can be added at a concentration of about 1 nM to about 1 M. In other embodiments, the additive can be added at a concentration of about 1 μM to about 1 M. In other embodiments, the additive can be added at a concentration of about 1 μM to about 1 mM.

[0085]

[0119] In some cases, in certain embodiments, water may be added to the lead halide precursor ink. For the sake of explanation and without limiting the disclosure to a particular theory or mechanism, the presence of water affects the perovskite thin film crystal growth. Under normal environmental conditions, water is absorbed as vapor from the air. However, by directly adding water to a specific concentration of the lead halide precursor ink, the crystallinity of the perovskite PV can be controlled. Suitable water includes distilled water, deionized water, or other water sources substantially free of contaminants (mineral-containing). Based on the light I-V sweep, it has been found that the perovskite PV power conversion efficiency can be increased by almost three times by adding water compared to a completely dry device.

[0086]

[0120] Water can be added to the lead halide precursor ink at various concentrations depending on the desired properties of the obtained perovskite material. In one embodiment, water may be added at a concentration of about 1 nL / mL to about 1 mL / mL. In other embodiments, water may be added at a concentration of about 1 μL / mL to about 0.1 mL / mL. In other embodiments, water may be added at a concentration of about 1 μL / mL to about 20 μL / mL.

[0087]

[0121] Next, the lead halide precursor ink can be deposited on a desired substrate. Suitable substrate layers may include any of the substrate layers described above in the present disclosure. As described above, the lead halide precursor ink may be deposited via various means including, but not limited to, drop casting, spin casting, slot die printing, screen printing, or inkjet printing. In certain embodiments, the lead halide precursor ink can be spin-coated onto the substrate for a period of about 5 seconds to about 600 seconds at a speed of about 500 rpm to about 10,000 rpm. In one embodiment, the lead halide precursor ink can be spin-coated onto the substrate at about 3000 rpm for about 30 seconds. The lead halide precursor ink can be deposited on the substrate in an ambient atmosphere within a humidity range of about 0% relative humidity to about 50% relative humidity. Next, the lead halide precursor ink can be dried in a substantially water-free atmosphere, i.e., an atmosphere with a relative humidity of less than 30%, to form a thin film.

[0088]

[0122] Next, the thin film can be thermally annealed at a temperature of about 20°C to about 300°C for a period of up to about 24 hours. In one embodiment, the thin film can be thermally annealed at a temperature of about 50°C for about 10 minutes. Next, the perovskite material active layer can be completed by a conversion process in which the precursor film is immersed or rinsed in a solution containing a solvent or a mixture of solvents (e.g., DMF, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide (DMSO), water) and salts (e.g., formamidinium iodide, guanidinium iodide, 1,2,2-triaminovinylammonium, 5-aminovaleric acid hydride) at a concentration of 0.001M to 10M. In certain embodiments, the thin film can also be thermally post-annealed in the same manner as the first line of this paragraph.

[0089]

[0123] In certain embodiments, a lead salt precursor can also be deposited on a substrate to form a lead salt thin film. The temperature of the substrate can be approximately equal to the ambient temperature or can be a controlled temperature between 0°C and 500°C. The lead salt precursor can be deposited by various methods known in the art, including, but not limited to, spin coating, slot die printing, inkjet printing, gravure printing, screen printing, sputtering, PE-CVD, thermal evaporation, spray coating. In certain embodiments, the deposition of the lead salt precursor can include a sheet-to-sheet or roll-to-roll manufacturing method. The deposition of the lead salt precursor can be performed in various atmospheres, such as atmospheric pressure (e.g., about 1 atmosphere depending on altitude and atmospheric conditions) or a pressure lower than atmospheric pressure (e.g., 1 mTorr to 500 mTorr). The deposition atmosphere can include ambient air, a controlled humidity environment (e.g., 0 to 100 g of H 2 O / m 3 ), pure argon, pure nitrogen, pure oxygen, pure hydrogen, pure helium, pure neon, pure krypton, pure CO 2 , or any combination of the above gases. The controlled humidity environment can include an environment where the absolute humidity or % relative humidity is maintained at a fixed value, or an environment where the absolute humidity or % relative humidity changes according to a predetermined set point or a predetermined function. In certain embodiments, the deposition can be performed in a controlled humidity environment where the relative humidity is 0% to 50%. In other embodiments, the deposition can be performed in a controlled humidity environment that includes a gas with 0 g H 2 O / m 3 or more and 20 g H 2 O / m 3 or less.

[0090]

[0124] The lead salt precursor may be a liquid, gas, solid, or a combination of these states such as a solution, suspension, colloid, foam (bubble), gel, or aerosol. In certain embodiments, the lead salt precursor may be a solution containing one or more solvents. For example, the lead salt precursor can contain one or more of N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. The lead salt precursor may be a single lead salt (e.g., lead(II) iodide, lead(II) thiocyanate) or any combination of those disclosed herein (e.g., PbI 2 +PbCl 2 ;PbI 2 +Pb(SCN) 2 ). The lead salt precursor may also include one or more additives such as amino acids (e.g., 5-aminovaleric acid hydroiodide), 1,8-diiodooctane, 1,8-dithiooctane, formamidinium halide, acetic acid, trifluoroacetic acid, methylammonium halide, or water. The lead halide precursor ink can be dried in a substantially water-free atmosphere, i.e., an atmosphere with a relative humidity of less than 30%, to form a thin film. The thin film can then be thermally annealed at a temperature of about 20 °C to about 300 °C for a period of up to about 24 hours. The annealing can be performed in various atmospheres such as atmospheric pressure (e.g., about 1 atmosphere depending on altitude and atmospheric conditions) or a pressure lower than atmospheric pressure (e.g., 1 mTorr to 500 mTorr). The annealing atmosphere can be ambient air, a controlled humidity environment (e.g., 0 to 100 g of H 2 O / m 3 ), pure argon, pure nitrogen, pure oxygen, pure hydrogen, pure helium, pure neon, pure krypton, pure CO 2, or any combination of the above gases. The controlled humidity environment may include an environment where the absolute humidity or % relative humidity is maintained at a fixed value, or an environment where the absolute humidity or % relative humidity changes according to a predetermined set point or a predetermined function. In certain embodiments, annealing may be performed in a controlled humidity environment where the relative humidity is between 0% and 50%. In other embodiments, annealing may be performed in a controlled humidity environment containing a gas of 2 O / m 3 or more and 20 g H 2 O / m 3 or less.

[0091]

[0125] After the lead salt precursor is deposited, a second salt precursor (e.g., formamidinium iodide, formamidinium thiocyanate, guanidinium thiocyanate) may be deposited on the lead salt thin film, where the lead salt thin film may be approximately equal to the ambient temperature or may be a temperature controlled between 0 °C and 500 °C. In certain embodiments, the second salt precursor may be deposited at ambient temperature or at an elevated temperature between about 25 °C and 125 °C. The second salt precursor may be deposited by various methods known in the art, including but not limited to spin coating, slot die printing, inkjet printing, gravure printing, screen printing, sputtering, PE-CVD, thermal evaporation, spray coating. The deposition of the second salt precursor can be carried out at atmospheric pressure (e.g., about 1 atm depending on altitude and atmospheric conditions) or at a pressure lower than atmospheric pressure (e.g., 1 mTorr to 500 mTorr) in various atmospheres. The deposition atmosphere may be ambient air, a controlled humidity environment (e.g., 0 to 100 g of H 2 O / m 3 ), pure argon, pure nitrogen, pure oxygen, pure hydrogen, pure helium, pure neon, pure krypton, pure CO 2 , or any combination of the above gases. The controlled humidity environment may include an environment where the absolute humidity or % relative humidity is maintained at a fixed value, or an environment where the absolute humidity or % relative humidity changes according to a predetermined set point or a predetermined function. In certain embodiments, the deposition may be performed in a controlled humidity environment where the relative humidity is between 0% and 50%. In other embodiments, the deposition may be performed in a controlled humidity environment containing a gas of 0 g H2 O / m 3 Greater than or equal to and 20 g H 2 O / m 3 It can be carried out in a controlled humidity environment containing the following gas.

[0092]

[0126] In certain embodiments, the second salt precursor may be a solution containing one or more solvents. For example, the second salt precursor may contain one or more of dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof.

[0093]

[0127] After deposition of the lead salt precursor and the second salt precursor, the substrate can be annealed. By annealing the substrate, the lead salt precursor and the second salt precursor can be converted into a perovskite material (e.g., FAPbI 3 , GAPb(SCN) 3 , FASnI 3 ). Annealing can be carried out in various atmospheres, such as atmospheric pressure (e.g., about 1 atm depending on altitude and atmospheric conditions) or a pressure lower than atmospheric pressure (e.g., 1 mTorr to 500 mTorr). The annealing atmosphere can be ambient air, a controlled humidity environment (e.g., 0 to 100 g of H 2 O / m 3 ), pure argon, pure nitrogen, pure oxygen, pure hydrogen, pure helium, pure neon, pure krypton, pure CO 2, or any combination of the above gases. The controlled humidity environment may include an environment where the absolute humidity or % relative humidity is maintained at a fixed value, or an environment where the absolute humidity or % relative humidity changes according to a predetermined set point or a predetermined function. In certain embodiments, annealing may be performed in a controlled humidity environment where the relative humidity is between 0% and 50%. In other embodiments, annealing may be performed in a controlled humidity environment containing a gas of 2 O / m 3 or more and 20 g H 2 O / m 3 or less. In certain embodiments, annealing can be performed at a temperature of 50°C to 300°C. Unless otherwise stated, any annealing or deposition process described herein can be carried out under the above conditions.

[0094]

[0128] For example, in certain embodiments, FAPbI 3 perovskite materials can be formed by the following process. First, PbI 2 versus PbCl 2A lead halide precursor (II) with a molar ratio of about 90:10 can be deposited on a substrate by spin coating or slot die printing. The lead halide precursor ink can be dried in a substantially water-free atmosphere, i.e., an atmosphere with a relative humidity of less than 30%, for about 1 hour (+15 minutes) to form a thin film. The thin film can then be thermally annealed at about 50 °C (+10 °C) for about 10 minutes. In other embodiments, the lead halide precursor may be deposited by inkjet printing, gravure printing, screen printing, sputtering, PE-CVD, atomic layer deposition, thermal evaporation, or spray coating. Next, a formamidinium iodide precursor containing formamidinium iodide dissolved in anhydrous isopropyl alcohol at a concentration of 25-60 mg / mL can be deposited on the lead halide thin film by spin coating or slot die printing. In other embodiments, the formamidinium iodide precursor may be deposited by inkjet printing, gravure printing, screen printing, sputtering, PE-CVD, atomic layer deposition, thermal evaporation, or spray coating. After depositing the lead halide precursor and the formamidinium iodide precursor, the substrate is annealed at a relative humidity of about 25% (about 4-7 g of H 2 O / m 3 air) and between about 125 °C and 200 °C to form a formamidinium lead iodide (FAPbI 3 ) perovskite material.

[0095]

[0129] In another embodiment, the perovskite material is C’CPbX 3may include, where C’ is one or more Group 1 metals (i.e., Li, Na, K, Rb, Cs). In certain embodiments, M’ can be cesium (Cs). In another embodiment, C’ can be rubidium (Rb). In another embodiment, C’ can be sodium (Na). In another embodiment, C’ can be potassium (K). In still other embodiments, the perovskite material may include C’vCwPbyXz, where C’ is one or more Group 1 metals and v, w, y, and z represent real numbers from 1 to 20. In certain embodiments, the perovskite material can be deposited as an active layer on a substrate layer, for example, by drop casting, spin casting, gravure coating, blade coating, reverse gravure coating, slot die printing, screen printing, or inkjet printing, using the processes described below.

[0096]

[0130] First, a lead halide solution is formed. An amount of lead halide can be masked in a clean and dry container in a controlled atmosphere. Suitable lead halides include, but are not limited to, lead(II) iodide, lead(II) bromide, lead(II) chloride, and lead(II) fluoride. The lead halide may be composed of a single lead halide species or may be composed of a mixture of lead halides in exact ratios. In certain embodiments, the lead halide mixture may be composed of any binary, ternary, or quaternary ratio of iodide, bromide, chloride, or fluoride from 0.001 to 100 mol%. In one embodiment, the lead halide mixture may include lead(II) chloride and lead(II) iodide in a ratio of about 10:90 mol:mol. In other embodiments, the lead halide mixture may include lead(II) chloride and lead(II) iodide in a ratio of about 5:95, about 7.5:92.5, or about 15:85 mol:mol.

[0097]

[0131] Alternatively, other lead salt precursors can be used in combination with or instead of the lead halide salt to form the lead salt solution. Suitable precursor salts include any combination of lead (II) or lead (IV) with the following anions: nitrate, nitrite, carboxylate, acetate, formate, oxalate, sulfate, sulfite, thiosulfate, phosphate, tetrafluoroborate, hexafluorophosphate, tetra(perfluorophenyl)borate, hydride, oxide, peroxide, hydroxide, nitride, arsenate, arsenite, perchlorate, carbonate, bicarbonate, chromate, dichromate, iodate, bromate, chlorate, chlorite, hypochlorite, hypobromite, cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide and tricyanomethanide, tricyanomethane, amide, and permanganate.

[0098]

[0132] The lead salt solution may further contain a lead (II) salt or a lead (IV) salt in a molar ratio of 0 to 100% with respect to the following metal ions Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr as salts of the anions.

[0099]

[0133] Next, a solvent can be added to the container to dissolve the lead halide solid to form a lead halide precursor ink. Suitable solvents include, but are not limited to, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the lead solid is dissolved in dry dimethylformamide (DMF). The lead solid can be dissolved at a temperature of about 20 to 150 °C. In one embodiment, the lead solid is dissolved at about 85 °C and can be dissolved only as much as necessary to form a solution, which can be done for up to about 72 hours. The resulting solution forms the basis of the lead halide precursor ink. In certain embodiments, the lead halide concentration of the lead halide precursor ink can be from about 0.001 M to about 10 M. In one embodiment, the lead halide concentration of the lead halide precursor ink can be about 1 M. In certain embodiments, the lead halide solution can further include an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrogen halide (e.g., 5-aminovaleric acid hydrochloride), an IFL surface modification (SAM) agent (e.g., those described above in the specification), or combinations thereof.

[0100]

[0134] Next, a Group 1 metal halide solution is formed. The amount of the Group 1 metal halide can be masked in a clean and dry container in a controlled atmosphere. Suitable Group 1 metal halides include, but are not limited to, cesium iodide, cesium bromide, cesium chloride, cesium fluoride, rubidium iodide, rubidium bromide, rubidium chloride, rubidium fluoride, lithium iodide, lithium bromide, lithium chloride, lithium fluoride, sodium iodide, sodium bromide, sodium fluoride, potassium iodide, potassium bromide, potassium chloride, and potassium fluoride. The Group 1 metal halide may comprise a single species of Group 1 metal halide or may comprise a mixture of Group 1 metal halides in an exact ratio. In one embodiment, the Group 1 metal halide may comprise cesium iodide. In another embodiment, the Group 1 metal halide may comprise rubidium iodide. In another embodiment, the Group 1 metal halide may comprise sodium iodide. In another embodiment, the Group 1 metal halide may comprise potassium iodide.

[0101]

[0135] Alternatively, other Group 1 metal salt precursors can be used in combination with or in place of the Group 1 metal halide salt. Suitable precursor Group 1 metal salts may comprise any combination of a Group 1 metal and the following anions: nitrate, nitrite, carboxylate, acetate, formate, oxalate, sulfate, sulfite, thiosulfate, phosphate, tetrafluoroborate, hexafluorophosphate, tetra(perfluorophenyl)borate, hydride, oxide, peroxide, hydroxide, nitride, arsenate, arsenite, perchlorate, carbonate, bicarbonate, chromate, sulfite, dichromate, iodate, bromate, chlorate, chlorite, hypochlorite, hypobromite, cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide and tricyanomethanide, tricyanomethane, amide, and permanganate.

[0102]

[0136] Next, a solvent can be added to the container to dissolve the Group 1 metal halide solid to form a Group 1 metal halide solution. Suitable solvents include, but are not limited to, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the Group 1 metal halide solid is dissolved in dry dimethylformamide (DMF). The Group 1 metal halide solid can be dissolved at a temperature of about 20 to 150 °C. In one embodiment, the Group 1 metal halide solid is dissolved at room temperature (i.e., about 25 °C). The Group 1 metal halide solid can be dissolved for as long as necessary to form a solution, which may be up to about 72 hours. The resulting solution forms a Group 1 metal halide solution. In certain embodiments, the lead halide concentration of the Group 1 metal halide solution may be from about 0.001 M to about 10 M. In one embodiment, the lead halide concentration of the Group 1 metal halide solution may be about 1 M. In certain embodiments, the Group 1 metal halide solution may further include an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrogen halide (e.g., 5-aminovaleric acid hydrochloride), an IFL surface modification (SAM) agent (e.g., those described above in the specification), or combinations thereof.

[0103]

[0137] Next, a lead halide solution and a Group 1 metal halide solution are mixed to form a thin film precursor ink. The lead halide solution and the Group 1 metal halide solution may be mixed such that the ratio of the molar concentration of the Group 1 metal halide in the resulting thin film precursor ink is 0% to 25% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 1% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 5% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 10% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 15% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 20% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 25% of the molar concentration of the lead halide. In certain embodiments, the lead halide solution and the Group 1 metal halide solution can be stirred or agitated during or after mixing.

[0104]

[0138] Next, the thin film precursor ink can be deposited on a desired substrate. The suitable substrate layer may include any substrate layer identified prior to the present disclosure. As described above, the thin film precursor ink can be deposited via various means including, but not limited to, drop casting, spin casting, gravure coating, blade coating, reverse gravure coating, slot die printing, screen printing, or inkjet printing. In certain embodiments, the thin film precursor ink can be spin-coated on the substrate at a speed of about 500 rpm to about 10,000 rpm for a period of about 5 seconds to about 600 seconds. In one embodiment, the thin film precursor ink can be spin-coated on the substrate at about 3000 rpm for about 30 seconds. The thin film precursor ink may be deposited on the substrate in an ambient atmosphere in a humidity range of about 0% relative humidity to about 50% relative humidity. Next, the thin film precursor ink is dried in an atmosphere substantially free of water, i.e., with a relative humidity of less than 30% or less than 7 g H 2 O / m 3 to form a thin film.

[0105]

[0139] Next, the thin film can be thermally annealed at a temperature of about 20°C to about 300°C for a period of up to about 24 hours. In one embodiment, the thin film can be thermally annealed at a temperature of about 50°C for about 10 minutes. Next, the perovskite material active layer can be completed by a conversion process in which the precursor film is immersed or rinsed in a salt solution containing a solvent or a mixture of solvents (e.g., DMF, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide (DMSO), water) at a concentration of 0.001 M to 10 M and a salt (e.g., methylammonium iodide, formamidinium iodide, guanidinium iodide, 1,2,2-triaminovinylammonium iodide, 5-aminovaleric acid hydride). In certain embodiments, the perovskite material thin film can also be thermally post-annealed in the same manner as the first line of this paragraph.

[0106]

[0140] In one embodiment, the salt solution can be prepared by forming a salt cake in a clean and dry container in a controlled atmosphere. Suitable salts include, but are not limited to, methylammonium iodide, formamidinium iodide, guanidinium iodide, imidazolium iodide, ethenetetramine iodide, 1,2,2-triaminovinylammonium iodide, and 5-aminovaleric acid hydroiodide. Other suitable salts can include any organic cation described in the "Perovskite Materials" section, and this salt can include a single salt or can include a salt mixture in an exact ratio. In one embodiment, the salt can include methylammonium iodide. In another embodiment, the salt can include formamidinium iodide. Next, a solvent can be added to the container to dissolve the solid salt to form a salt solution. Suitable solvents include, but are not limited to, DMF, acetonitrile, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide (DMSO), water, and combinations thereof. In one embodiment, a solid formamidinium iodide salt is dissolved in isopropanol. The solid salt can be dissolved at about 20 to about 150 °C. In one embodiment, the solid salt is dissolved at room temperature (i.e., about 25 °C). The solid salt can be dissolved as long as necessary to form a solution, which can occur over a period of up to about 72 hours. The resulting solution forms a salt solution. In one embodiment, the salt concentration of the salt solution can be from about 0.001 M to about 10 M. In one embodiment, the salt concentration of the salt solution is a salt concentration of about 1 M.

[0107]

[0141] For example, when using the above method with a lead(II) iodide solution, a cesium iodide solution, and a methylammonium iodide (MA) salt solution, a perovskite material of the formula Cs i MA 1-i PbI 3 (where i represents a number between 0 and 1) may be obtained. As another example, by using a lead(II) iodide solution, a rubidium iodide solution, and a formamidinium iodide (FA) salt solution, a formula Rb i FA1-i PbI 3 (wherein i represents a number between 0 and 1), a perovskite material can be obtained. As another example, when using a lead(II) iodide solution, a cesium iodide solution, and a formamidinium iodide (FA) salt solution, the formula Cs i FA 1-i PbI 3 (wherein i represents a number between 0 and 1), a perovskite material can be obtained. As another example, when using a lead(II) iodide solution, a potassium iodide solution, and a formamidinium iodide (FA) salt solution, the formula K i FA 1-i PbI 3 (wherein i represents a number between 0 and 1), a perovskite material can be obtained. As another example, by using a lead(II) iodide solution, a sodium iodide solution, and a formamidinium iodide (FA) salt solution, the formula Na i FA 1-i PbI 3 (wherein i represents a number between 0 and 1), a perovskite material can be obtained. As another example, when using a lead(II) lead-chloride (II) mixed solution, a cesium iodide solution, and a formamidinium iodide (FA) salt solution, the formula Cs i FA 1-i PbI 3-y Cl y (wherein i represents a number between 0 and 1, and y represents a number between 0 and 3), a perovskite material can be obtained.

[0108]

[0142] In certain embodiments, the lead halide solution described above may have a ratio of PbI 2 to PbCl 2 of 90:10 on a molar basis. A cesium iodide (CsI) solution can be added to the lead halide solution by the method described above to form a thin film precursor ink in which CsI is 10 mol%. The FAPbI 3 perovskite material can be manufactured by the method described above using this thin film precursor solution. When cesium ions are added with a CsI solution as described above, chloride anions and cesium atoms are in FAPbI 3It may be incorporated into the crystal lattice. This may result in a greater degree of lattice contraction compared to the case where cesium or rubidium ions are added without adding chloride ions as described above. Table 1 below shows the lattice parameters of FAPbI 2 containing 10 mol% rubidium and 20 mol% chloride (e.g., 10 mol% PbCl 3 ), FAPbI containing 10 mol% cesium 3 perovskite materials, and the lattice parameters of 10 mol% cesium containing 20 mol% chloride. Here, the mol% concentration represents the concentration of the additive relative to the lead atoms in the lead halide solution. As can be seen in Table 1, the lattice parameters of the FAPbI

[0109]

Table 1

[0143] Furthermore, there is data indicating that the cubic structure of the FAPbI 3 perovskite material added with rubidium, cesium, and / or chloride is the Pm3-m cubic structure. It was observed that the FAPbI 3 perovskite containing 10 mol% Rb and 10 mol% Cl, or 10 mol% Cs, or 10 mol% Cs and 10 mol% Cl maintains the cubic Pm3-m cubic crystal structure. Figure 29 shows the X-ray diffraction patterns corresponding to each sample shown in Table 1. Tables 2-4 show the X-ray diffraction peaks and intensities of the three perovskite materials shown in Table 1. The data were collected under ambient conditions using a Rigaku Miniflex600 with a Cu Kα radiation source at a scan rate of 1.5 degrees 2θ / min.

[0110]

Table 2

[0111]

Table 3

[0112]

Table 4

[0144] For a cubic Pm3-m material with a lattice constant of 6.3375 Å, Table 5 shows the X-ray diffraction pattern geometrically predicted under Cu-Kα radiation. As can be seen from the data, the diffraction patterns of the perovskite materials produced with 10 mol% Rb and 10 mol% Cl, 10 mol% Cs, and 10% Cs and 10% Cl each match the pattern expected for the cubic Pm3-m perovskite material.

[0113]

Table 5

[0145] Reinforced perovskite So-called "layered" 2D perovskites are known to form when the perovskite is formulated with an organic cation having a longer alkyl chain than the methylammonium and formamidinium cations described hereinabove. Layered 2D perovskites include structures such as the Ruddlesden-Popper phase, the Dion-Jacobson phase, and the Aurivillius phase. For example, by substituting 1-butylammonium for the above methylammonium or other cation, a Ruddlesden-Popper 2D perovskite may occur during the formation of the perovskite by a "one-step" method (not described herein). In this perovskite, 1-butylammonium hinders the perovskite from forming a complete crystal lattice, and instead the perovskite is formed of "sheets" of perovskite having a single crystal structure in its thickness. FIG. 5 shows the structure of a Ruddlesden-Popper perovskite 5500 having a 1-butylammonium cation 5510. As can be seen from FIG. 5, at the "tail" of the butylammonium cation 5510, the lead and iodide portions of the perovskite material are separated from other lead and iodide structures, resulting in a "sheet" of 2D perovskite. Therefore, when the Ruddlesden-Popper form of the perovskite is not desirable, it may not be desirable to introduce a "bulky" organic cation such as 1-butylammonium or benzylammonium during the formation of the perovskite material.

[0146] However, when a diluted amount of a 1-butylammonium solution is added before annealing the perovskite material, perovskite may form as shown in FIG. 6. FIG. 6 shows an embodiment of a perovskite material 2000 involving the addition of an alkylammonium cation for surface passivation. In the illustrated embodiment, formamidinium lead iodide (FAPbI 3)The surface of the perovskite material 2010 is shown to have 1-butylammonium cations 2020 on the surface. In certain embodiments, 1-butylammonium cations, or other "bulky" organic cations as described herein, can diffuse into the perovskite material near the surface of the perovskite material's crystal lattice. In certain embodiments, 1-butylammonium cations, or other "bulky" organic cations as described herein, can be present within 50 nm of the crystal lattice surface or grain boundaries into the perovskite material. Incorporating "bulky" organic cations such as 1-butylammonium near or on the surface of the perovskite material can cause the formula of the perovskite material to deviate from the "ideal" stoichiometry of the perovskite materials disclosed herein. For example, due to the incorporation of such organic cations, the perovskite material may be represented by a formula that is either sub-stoichiometric or super-stoichiometric with respect to the formula CMX 3 described herein. In this case, the general formula of the perovskite material can be represented as CxMyXz. Here, x, y, and z are real numbers. In certain embodiments, the perovskite material may be represented by the formula C’ 2 C n-1 M n X 3n+1 (where n is an integer). For example, when n = 1, the perovskite material can be represented by the formula C’ 2 MX 4 ; when n = 2, the perovskite material can be represented by the formula C’ 2 CM 2 X 7 ; when n = 3, the perovskite material can be represented by the formula C’ 2 C 2 M 3 X 10 ; and when n = 4, the perovskite material can be represented by the formula C’ 2 C 3 M 4 X 13 . As shown in FIG. 30, the n value indicates the thickness of the inorganic metal halide sublattice of the perovskite material. The formula C’ 2 C n-1 Mn X 3n+1 The phase of the perovskite material represented by X can be formed in regions where bulky organic cations diffuse into the crystal lattice of the perovskite material or enter in other ways. For example, such a phase can be present within 50 nanometers from the surface of the crystal lattice (e.g., the surface or grain boundaries) of the perovskite material containing bulky organic cations as disclosed herein.

[0114]

[0147] The carbon “tail” of the 1-butylammonium ion can provide protective properties to the surface of the perovskite by effectively keeping other molecules away from the surface. In certain embodiments, the alkyl group “tail” of the 1-butylammonium ion may be oriented away from or parallel to the surface of the perovskite material. In particular, the 1-butylammonium “tail” has hydrophobic properties that prevent water molecules from contacting the surface of the perovskite and protect the surface of the perovskite material 2010 from water in the environment. In addition, the 1-butylammonium cation can also act to passivate the surface and any grain boundaries or defects in the perovskite material 2010. Passivation refers to the electrical property of preventing the accumulation of charge or “trap states” at the surface or grain boundaries of the perovskite material 2010. By acting to passivate a portion of the perovskite material 2010, 1-butylammonium can improve the charge transfer into and out of the perovskite material 2010 and improve the electrical properties of the photoactive layer.

[0115]

[0148] In some embodiments, other organic cations can be applied instead of or in combination with 1-butylammonium. Examples of other "bulky" organic cations that can act on the surface passivation of perovskite materials include ethylammonium, propylammonium, n-butylammonium; perylene n-butylamine imide; butane-1,4-diammonium; 1-pentylammonium; 1-hexylammonium; poly(vinylammonium); phenylethylammonium; benzylammonium; 3-phenyl-1-propylammonium; 4-phenyl-1-butylammonium; 1,3-dimethylbutylammonium; 3,3-dimethylbutylammonium; 1-heptylammonium; 1-octylammonium; 1-nonylammonium; 1-decylammonium; and 1-icosanylammonium (icosanethylammonium), but are not limited thereto. Further, in bulky organic cations having a tail containing one or more heteroatoms in addition to the cationic species, the heteroatoms can coordinate, bond, or integrate with the perovskite material crystal lattice. The heteroatom can be any atom of the tail that is not hydrogen or carbon and includes nitrogen, sulfur, oxygen, or phosphorus.

[0116]

[0149] Other examples of "bulky" organic cations include ammonium groups, phosphonium groups, or other cationic groups that can be incorporated into the "C-site of perovskite materials": benzene, pyridine, naphthalene, anthracene, xanthene, phenanthrene, tetracene, chrysene, tetraphene, benzo[c]phenanthrene, triphenylene, pyrene, perylene, coronulenene, coronene, substituted dicarboximide, aniline, N-(2-aminoethyl)-2-isoindole-1,3-dione, 2-(1-aminoethyl)naphthalene, 2-triphenylene-O-ethylamine ether, benzylamine, benzylammonium salts, N-n-butyl-N'-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 1-(4-alkylphenyl)methanamine, 1-(4-alkyl-2-phenyl)ethanamine, 1-(4-alkyl-2-phenyl)methanamine, 1-(3-alkyl-5-alkylphenyl)methanamine, 1-(3-alkyl-5-alkyl-2-phenyl)ethanamine, 1-(4-alkyl-2-phenyl)ethanamine, 2-ethylamine-7-alkyl-naphthalene, 2-ethylamine-6-alkyl-naphthalene, 1-ethylamine-7-alkyl-naphthalene, 1-ethylamine-6-alkyl-naphthalene, 2-methylamine-7-alkyl-naphthalene, 2-methylamine-6-alkyl-naphthalene, 1-methylamine-7-alkyl-naphthalene, 1-methylamine-6-alkyl-naphthalene, N-n-aminoalkyl-N'-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 1-(3-butyl-5-methoxybutylphenyl)methanamine, 1-(4-pentylphenyl)methanamine, 1-[4-(2-methylpentyl)-2-phenyl]ethanamine, 1-(3-butyl-5-pentyl-2-phenyl)ethanamine, 2-(5-[4-methylpentyl]-2-naphthyl)ethanamine, N-7-tridecyl-N'-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), N-n-heptyl-N'-4-aminobutylperylene-3,4,9,10-bis(dicarboximide), 2-(6-[3-methoxylpropyl]-2-naphthyl)ethanamine, and the following molecules functionalized with these groups can be mentioned.Figures 17 to 28 illustrate the structures of these organic molecules according to an embodiment. With respect to FIGS. 17 and 18, each "R group", Rx, is H, R', Me, Et, Pr, Ph, Bz, F, Cl, Br, I, NO. 2 , OR', NR' 2 , SCN, CN, N 3 , SR', where R' may be any alkyl, alkenyl, or alkynyl chain. Further, at least one of the illustrated Rx groups is (CH 2 )nEXy or (CH 2 )nC(EXy) 2and may be, where n and y may or may not be equal, E can be selected from the group consisting of C, Si, O, S, Se, Te, N, P, As, or B, X is a halide or pseudohalide, for example, F, Cl, Br, I, CN, SCN, or H. Further, with respect to Figure 19, the illustrated molecule may contain any hydrohalide of each illustrated amine, for example, a benzylammonium salt, where the illustrated X group can be F, Cl, Br, I, SCN, CN, or any other pseudohalide. Other non-halide acceptable anions include, but are not limited to, nitrate, nitrite, carboxylate, acetate, acetylacetonate, formate, oxalate, sulfate, sulfite, thiosulfate, phosphate, tetrafluoroborate, hexafluorophosphate, tetra(perfluorophenyl)borate, hydride, oxide, peroxide, hydroxide, nitride, arsenate, arsenite, perchlorate, carbonate, bicarbonate, chromate, sulfite, dichromate, iodate, bromate, chlorate, chlorite, hypochlorite, hypobromite, cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide and tricyanomethanide, tricyanomethane, amide, and permanganate.Suitable R groups include hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or their isomers; alkanes, alkenes or alkynes CxHy (x = 1 - 20, y = 1 - 42, cyclic, branched or straight-chain); halogenated alkyls, alkyl halides CxHyXz, (where x = 1 - 20, y = 0 - 42, z = 1 - 42, X = F, Cl, Br, or I); any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes containing at least one nitrogen in the ring (e.g., pyridine, pyrrole, pyrrolidine, piperidine, tetrahydroquinoline); any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); any nitrogen-containing group (nitroxide, amine); any phosphorus-containing group (phosphoric acid); any boron-containing group (e.g., boronic acid); any organic acid (e.g., acetic acid, propanoic acid) and its ester or amide derivatives; any amino acid (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valeric acid) including α, β, γ and higher derivatives; any silicon-containing group (e.g., siloxane); and any alkoxy or group, -OCxHy (where x = 0 - 20, y = 1 - 42), but are not limited thereto.

[0117]

[0150] Furthermore, in certain embodiments, bulky organic cations may passivate grain boundaries and surface defects in the perovskite material. FIG. 7 shows an example of a perovskite material layer 3000 where 1-butylammonium 3020 passivates both the surface and grain boundaries 3015 of the bulk perovskite material 3010. As described above, the alkyl tails of these ions can also repel water and other polar species and form a hydrophobic layer that prevents such species from reaching the surface of the perovskite material. As seen in FIG. 7, the "tails" of the bulky organic cations may not be chemically bonded (e.g., covalently or ionically) to the surface or grain boundaries 3015 of the perovskite material layer 3000. As used herein, the "tail" of any bulky organic cation refers to the non-ionic carbon structure of the bulky organic cation. For example, the tail of 1-butylammonium is the butyl group, and the tail of benzylammonium is the benzyl group.

[0118]

[0151] The bulky organic cation's tail can also take other arrangements with respect to the surface or grain boundaries of the perovskite material. Generally, the cationic "head" of the bulky organic cation does not diffuse beyond 50 nanometers from the surface or grain boundaries of the perovskite material. The interaction between the tail and the perovskite material is weak and is oriented away from the surface of the perovskite material crystallite. The tail may have intermolecular interactions (e.g., dipole-dipole or hydrogen bonding) with the surface of the perovskite material crystallite, resulting in an arrangement where the tail is oriented towards the surface of the perovskite material crystallite. In certain embodiments, the tail of a bulky organic cation present in the perovskite material may not interact with the surface or grain boundaries of the perovskite material, while the tails of other bulky organic cations in the perovskite material may interact with the surface or grain boundaries of the perovskite material. The tail may include a heteroatom or anion (i.e., zwitterion) having at least one lone pair of electrons that can interact covalently with the surface of the perovskite material crystallite via a metal atom (e.g., Pb, Sn, Ge, In, Bi, Cu, Ag, Au) present in the perovskite material. Also, the tail may include a cationic species such as diammonium butane described herein that can be incorporated into the perovskite material by substitution on at least two "C" cation sites (such as formamidinium). Also, the tail containing the cationic species can crosslink two layers of the 2D perovskite material, tilt across the surface of the perovskite material crystallite, or be oriented away from the surface of the perovskite material crystallite in the same manner as described for non-ionic tails. In other embodiments, a bulky organic cation having a sufficiently large tail such as an imidazolium cation may simply be present on the perovskite surface or grain boundary without diffusing into the perovskite material.

[0119]

[0152] Furthermore, in other embodiments, sterically-hindered organic cations with different tail group lengths or sizes can be applied to the perovskite to passivate grain boundaries and surface defects in the perovskite material. FIG. 8 shows an example of a perovskite material layer 4000 with a combination of 1-butylammonium 4020, 1-nonylammonium 4021, 1-heptylammonium 4022, and 1-hexylammonium 4023 that passivate both the surface and grain boundaries 4015 of the bulk perovskite material 4010. In certain embodiments, any mixture of the alkylammonium compounds identified above can be applied to the perovskite material as described herein. FIG. 8 shows an example of a perovskite material layer 4000 with a combination of 1-butylammonium 4020, 1-nonylammonium 4021, 1-heptylammonium 4022, and 1-hexylammonium 4023 that passivate both the surface and grain boundaries 4015 of the bulk perovskite material 4010. In certain embodiments, any mixture of the alkylammonium compounds identified above can be applied to the perovskite material as described herein. In certain embodiments, the sterically-hindered organic cation may include a benzyl group. FIG. 8A shows an example of a perovskite material layer 45500 with various sterically-hindered organic cations containing a benzyl group that passivate both the surface and grain boundaries 4515 of the bulk perovskite material 4510.

[0120]

[0153] As described above, it has been shown that adding a 1-butylammonium surface coating to a perovskite material enhances the high-temperature durability of the perovskite in a humid environment. Figure 9 shows a comparison of images of perovskite materials with and without a 1-butylammonium ("BAI") surface coating over 48 days. The compositions of both perovskite materials are the same, and they were exposed to an environment with a temperature of 85°C and a relative humidity of 55% for 48 days. As can be seen from the photograph, the perovskite material without the 1-butylammonium surface coating became significantly lighter in color one day after exposure to the environment, indicating that the perovskite material had significantly deteriorated. The perovskite material with the 1-butylammonium surface coating gradually became brighter over 48 days and remained partially dark even after 48 days. This indicates that the perovskite material with the 1-butylammonium surface coating is more robust than the perovskite material without the 1-butylammonium surface coating during long-term exposure to a high-temperature environment.

[0121]

[0154] Figure 10 shows a comparison of images of perovskite materials with and without a 1-butylammonium ("BAI") surface coating over 7 days. The compositions of both perovskite materials are the same, and they were exposed to an environment with a temperature of 85°C and a relative humidity of 0% for 48 days. As can be seen from the photograph, the perovskite material without the 1-butylammonium surface coating became significantly lighter in color one day after exposure to the environment, indicating that the perovskite material had significantly deteriorated. The perovskite material with the 1-butylammonium surface coating showed almost no color change after 7 days. This indicates that the perovskite material with the 1-butylammonium surface coating was not completely destroyed during long-term exposure to a high-temperature and high-humidity environment.

[0122]

[0155] In other embodiments, perylene n-butylamine imide can be applied to the surface of the perovskite material as described above with respect to 1-butylammonium. FIGS. 11A - D show various perylene monoimide and diimide that can be applied to the surface of the perovskite material according to the present disclosure. FIG. 12 shows an embodiment of a perovskite material 2500 with the addition of an alkylammonium cation for surface passivation. In the illustrated embodiment, the surface of the formamidinium lead iodide (FAPbI 3 ) perovskite material 2510 is shown to have perylene n-butylamine imide 2520 on the surface. Similar to the 1-butylammonium shown in FIG. 6, the carbon “tail” of the perylene n-butylamine imide ion can provide protective properties to the perovskite surface by effectively keeping other molecules away from the surface. In particular, the perylene n-butylamine imide “tail” is hydrophobic, preventing water molecules from contacting the surface of the perovskite and protecting the surface of the perovskite material 2510 from water in the environment. In addition, the perylene n-butylamine imide cation can also act to passivate the surface and any grain boundaries or defects by the perovskite material 2510. By acting to passivate a portion of the perovskite material 2510, the perylene n-butylamine imide can promote improved charge transfer into and out of the perovskite material 2510 and improve the electrical properties of the photoactive layer.

[0123]

[0156] An exemplary method for depositing 1-butylammonium prior to annealing the perovskite material is described below.

[0124]

[0157] First, a precursor ink of lead halide is formed. The amount of lead halide can be masked in a clean and dry container in a controlled atmosphere environment (e.g., a controlled atmosphere box with a port hole including gloves, which can operate substances in an airless environment). Suitable lead halides include, but are not limited to, lead(II) iodide, lead(II) bromide, lead(II) chloride, and lead(II) fluoride. The lead halide may be composed of a single lead halide species or may be composed of a mixture of lead halides in an exact ratio. In certain embodiments, the lead halide mixture may be composed of any binary, ternary, or quaternary ratio of 0.001 - 100 mol% iodide, bromide, chloride, or fluoride. In one embodiment, the lead halide mixture may include lead(II) chloride and lead(II) iodide in a ratio of about 10:90 mol:mol. In other embodiments, the lead halide mixture may include lead(II) chloride and lead(II) iodide in a ratio of about 5:95, about 7.5:92.5, or about 15:85 mol:mol.

[0125]

[0158] Alternatively, other lead salt precursors can be used, either with or instead of the lead halide salt, to form the precursor ink. Suitable precursor salts can include any combination of lead(II) or lead(IV) with the following anions: nitrate, nitrite, carboxylate, acetate, acetylacetonato, formate, oxalate, sulfate, sulfite, thiosulfate, phosphate, tetrafluoroborate, hexafluorophosphate, tetra(perfluorophenyl)borate, hydride, oxide, peroxide, hydroxide, arsenate, arsenite, perchlorate, carbonate, bicarbonate, chromate, dichromate, iodate, bromate, chlorate, chlorite, hypochlorite, hypobromite, cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide and tricyanomethanide, tricyanomethane, amide, and permanganate.

[0126]

[0159] The precursor ink may further contain a lead (II) salt or a lead (IV) salt in a molar ratio of 0 to 100% with respect to the following metal ions Be, Mg, Ca, Sr, Ba, Fe, Cd, Co, Ni, Cu, Ag, Au, Hg, Sn, Ge, Ga, Pb, Pb, In, Tl, Sb, Bi, Ti, Zn, Cd, Hg, and Zr as the salt of the anion.

[0127]

[0160] Next, a solvent can be added to the container to dissolve the lead solid to form a lead halide precursor ink. Suitable solvents include, but are not limited to, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the lead solid is dissolved in dry dimethylformamide (DMF). The lead solid can be dissolved at a temperature of about 20 to 150 °C. In one embodiment, the lead solid is dissolved at about 85 °C and can be dissolved only as much as necessary to form a solution, which can be carried out for up to about 72 hours. The resulting solution forms the basis of the lead halide precursor ink. In certain embodiments, the lead halide concentration of the lead halide precursor ink can be from about 0.001 M to about 10 M. In one embodiment, the lead halide concentration of the lead halide precursor ink can be about 1 M. In certain embodiments, the lead halide solution may further contain an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrogen halide (e.g., 5-aminovaleric acid hydrochloride), an IFL surface modification (SAM) agent (e.g., those described above in the specification), or combinations thereof.

[0128]

[0161] In some cases, specific additives may be added to the lead halide precursor ink to affect the final perovskite crystallinity and stability. In certain embodiments, the lead halide precursor ink may further include an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrogen halide (e.g., 5-aminovaleric acid hydrochloride), an IFL surface modification (SAM) agent (e.g., those described above in the specification), or combinations thereof. In one embodiment, formamidinium chloride may be added to the lead halide precursor ink. In other embodiments, halides of any of the cations described above in this specification can be used. In certain embodiments, a combination of additives can be added to the lead halide precursor ink, including, for example, a combination of formamidinium chloride and 5-aminovaleric acid chloride.

[0129]

[0162] Additives containing formamidinium chloride and / or 5-aminovaleric acid chloride can be added to the lead halide precursor ink at various concentrations depending on the desired properties of the resulting perovskite material. In one embodiment, the additive can be added at a concentration of about 1 nM to about 1 M. In other embodiments, the additive can be added at a concentration of about 1 μM to about 1 M. In other embodiments, the additive can be added at a concentration of about 1 μM to about 1 mM.

[0130]

[0163] In one embodiment, a Group 1 metal halide solution is formed for addition to the lead halide precursor ink. The amount of the Group 1 metal halide can be masked in a clean and dry container in a controlled atmosphere. Suitable Group 1 metal halides include, but are not limited to, cesium iodide, cesium bromide, cesium chloride, cesium fluoride, rubidium iodide, rubidium bromide, rubidium chloride, rubidium fluoride, lithium iodide, lithium bromide, lithium chloride, lithium fluoride, sodium iodide, sodium bromide, sodium fluoride, potassium iodide, potassium bromide, potassium chloride, and potassium fluoride. The Group 1 metal halide may comprise a single species of Group 1 metal halide or may comprise a mixture of Group 1 metal halides in exact ratios. In one embodiment, the Group 1 metal halide may comprise cesium iodide. In another embodiment, the Group 1 metal halide may comprise rubidium iodide. In another embodiment, the Group 1 metal halide may comprise sodium iodide. In another embodiment, the Group 1 metal halide may comprise potassium iodide.

[0131]

[0164] Alternatively, other Group 1 metal salt precursors can be used with or in place of the Group 1 metal halide salt to form a Group 1 metal salt solution. Suitable precursor Group 1 metal salts can include any combination of nitrates, nitrites, carboxylates, acetates, formates, oxalates, sulfates, sulfites, thiosulfates, phosphates, tetrafluoroborates, hexafluorophosphates, tetra(perfluorophenyl)borates, hydrides, oxides, peroxides, hydroxides, nitrides, arsenates, arsenites, perchlorates, carbonates, bicarbonates, chromates, iodates, bromates, chlorates, chlorites, hypochlorites, hypobromites, cyanates, isocyanates, thiocyanates, isothiocyanates, azides, tetracarbonylcobaltates, carbamoyldicyanomethanides, dicyanonitrosomethanides, dicyanamide, and tricyanomethanides, amides, and permanganates.

[0132]

[0165] Next, a solvent can be added to the container to dissolve the Group 1 metal halide solid to form a Group 1 metal halide solution. Suitable solvents include, but are not limited to, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the Group 1 metal halide solid is dissolved in dry dimethylformamide (DMF). The Group 1 metal halide solid can be dissolved at a temperature of about 20 to 150 °C. In one embodiment, the Group 1 metal halide solid is dissolved at room temperature (i.e., about 25 °C). The Group 1 metal halide solid can be dissolved for as long as necessary to form a solution, which can be up to about 72 hours. The resulting solution forms a Group 1 metal halide solution. In certain embodiments, the lead halide concentration in the Group 1 metal halide solution can be from about 0.001 M to about 10 M. In one embodiment, the lead halide concentration in the Group 1 metal halide solution can be about 1 M. In certain embodiments, the Group 1 metal halide solution can further include an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrogen halide (e.g., 5-aminovaleric acid hydrochloride), an IFL surface modification (SAM) agent (e.g., those described above in the specification), or combinations thereof.

[0133]

[0166] Next, a lead halide solution and a Group 1 metal halide solution are mixed to form a thin film precursor ink. The lead halide solution and the Group 1 metal halide solution may be mixed such that the ratio of the molar concentration of the Group 1 metal halide in the resulting thin film precursor ink is 0% to 25% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 1% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 5% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 10% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 15% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 20% of the molar concentration of the lead halide. In certain embodiments, the thin film precursor ink may have a molar concentration of the Group 1 metal halide that is 25% of the molar concentration of the lead halide. In certain embodiments, the lead halide solution and the Group 1 metal halide solution can be stirred or agitated during or after mixing.

[0134]

[0167] In some cases, in certain embodiments, water may be added to the lead halide precursor ink. In certain embodiments, the solvent may further comprise 2-methoxyethanol and acetonitrile. In certain embodiments, 2-methoxyethanol and acetonitrile can be added in a volume ratio of about 25:75 to about 75:25, or at least 25:75. In certain embodiments, the solvent may comprise, on a volume basis, a ratio of 2-methoxyethanol and acetonitrile to DMF of about 1:100 to about 1:1, or about 1:100 to about 1:5. In certain embodiments, the solvent may comprise, on a volume basis, a ratio of 2-methoxyethanol and acetonitrile to DMF of at least about 1:100. For purposes of explanation and without limiting the disclosure to any particular theory or mechanism, the presence of water affects perovskite thin film crystal growth. Under normal environmental conditions, water is absorbed as vapor from the air. However, by directly adding water to a specific concentration of lead halide precursor ink, the crystallinity of perovskite PV can be controlled. Suitable water includes distilled water, deionized water, or other water sources substantially free of contaminants (mineral-containing). Based on light I-V sweeps, it has been found that the perovskite PV power conversion efficiency is nearly tripled by the addition of water compared to a completely dry device.

[0135]

[0168] Water can be added to the lead halide precursor ink at various concentrations depending on the desired properties of the resulting perovskite material. In one embodiment, water may be added at a concentration of about 1 nL / mL to about 1 mL / mL. In other embodiments, water may be added at a concentration of about 1 μL / mL to about 0.1 mL / mL. In other embodiments, water may be added at a concentration of about 1 μL / mL to about 20 μL / mL.

[0136]

[0169] Next, a lead halide precursor ink or a thin film precursor ink can be deposited on a desired substrate. Suitable substrate layers may include any of the substrate layers described above in this disclosure. As described above, the lead halide precursor ink or the thin film precursor ink may be deposited via various means including, but not limited to, drop casting, spin casting, slot die printing, screen printing, or inkjet printing. In certain embodiments, the lead halide precursor ink or the thin film precursor ink can be spin-coated onto the substrate at a rate of about 500 rpm to about 10,000 rpm for a period of about 5 seconds to about 600 seconds. In one embodiment, the lead halide precursor ink or the thin film precursor ink can be spin-coated onto the substrate at about 3000 rpm for about 30 seconds. The lead halide precursor ink or the thin film precursor ink can be deposited onto the substrate in an ambient atmosphere within a humidity range of about 0% relative humidity to about 50% relative humidity. Next, the lead halide precursor ink or the thin film precursor ink can be dried in an atmosphere substantially free of water, i.e., an atmosphere having a relative humidity of less than 30%, to form a thin film.

[0137]

[0170] After deposition of the lead halide precursor or thin film precursor, the above-mentioned bulky organic cations (e.g., benzylammonium, phenylethylammonium, ethylammonium, propylammonium, n-butylammonium; butane-1,4-diammonium; 1-pentylammonium; 1-hexylammonium; poly(vinylammonium); phenylethylammonium; 3-phenyl-1-propylammonium; 4-phenyl-1-butylammonium; 1,3-dimethylbutylammonium; 3,3-dimethylbutylammonium; 1-heptylammonium; 1-octylammonium; 1-nonylammonium; 1-decylammonium; 1-icosanylammonium; or any other bulky cation salt solution described herein or illustrated in FIGS. 17-28) may be applied to the thin film obtained from the deposition of the lead salt precursor and the second salt precursor. Examples of bulky organic salts include halides, nitrates, nitrites, carboxylates, acetates, formates, oxalates, sulfates, sulfites, thiosulfates, phosphates, tetrafluoroborates, hexafluorophosphates, tetra(perfluorophenyl)borates, hydrides, oxides, peroxides, hydroxides, nitrides, arsenates, arsenites, perchlorates, carbonates, bicarbonates, chromates, iodates, bromates, chlorates, chlorites, hypochlorites, hypobromites, cyanates, isocyanates, thiocyanates, isothiocyanates, azides, tetracarbonylcobaltates, carbamoyldicyanomethanides, dicyanonitrosomethanides, dicyanamide and tricyanomethanides, amides, and permanganates. The bulky organic cation salt solution can be formed by dissolving the bulky organic cation salt in a solvent such as alcohol, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof.In certain embodiments, the bulky organic cation salt can be dissolved in isopropyl alcohol. In certain embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be from 0.0001 M to 1.0 M. In other embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be from 0.01 M to 0.1 M. In certain embodiments, in other embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be from 0.02 to 0.05 M. In certain embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be about 0.05 M. The bulky organic cation salt solution can be deposited on the perovskite material precursor thin film by any method described herein for solution deposition. These methods can be deposited by various means including, but not limited to, spray coating, drop casting, spin casting, blade coating, slot die printing, screen printing, gravure printing, or inkjet printing. In one embodiment, the bulky organic cation salt can be 1-butylammonium iodide. In other embodiments, the bulky organic cation salt can be benzylammonium iodide. In yet another embodiment, the bulky organic cation salt can be phenylethylammonium iodide.

[0138]

[0171] Next, the thin film can be thermally annealed at a temperature of about 20°C to about 300°C for a period of up to about 24 hours. In one embodiment, the thin film can be thermally annealed at a temperature of about 50°C for about 10 minutes. Next, the perovskite material active layer can be completed by a conversion process in which the precursor film is immersed or rinsed in a salt solution containing a solvent or a mixture of solvents (e.g., DMF, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide (DMSO), water) at a concentration of 0.001 M to 10 M and salts (e.g., methylammonium iodide, formamidinium iodide, guanidinium iodide, 1,2,2-triaminovinylammonium iodide, 5-aminovaleric acid hydride). In certain embodiments, the perovskite material thin film can also be thermally post-annealed in the same manner as the first line of this paragraph.

[0139]

[0172] In some embodiments, after annealing, a second salt precursor (e.g., formamidinium iodide, formamidinium thiocyanate, or guanidinium thiocyanate) can also be deposited on the lead salt thin film to form a thin film. The temperature of the second salt precursor can be approximately equal to the ambient temperature or can be a controlled temperature between 0 °C and 500 °C. The second salt precursor can be deposited by various methods known in the art, including but not limited to spin coating, blade coating, slot die printing, inkjet printing, gravure printing, screen printing, sputtering, PE-CVD, thermal evaporation, spray coating. In some embodiments, the second salt solution may be deposited multiple times thereafter to form a thin film layer. In some embodiments, the precursor of the second salt can be a solution containing one or more solvents. For example, the second salt precursor may include one or more of dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethyl sulfoxide (DMSO), acetonitrile, methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof.

[0140]

[0173] In certain embodiments, any bulky organic cation salt described herein can be combined with a second salt solution prior to deposition of the second salt solution. In certain embodiments, a bulky organic cation salt solution can be prepared as described above and mixed with the second salt solution prior to deposition of the second salt solution. In certain embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be from 0.0001 M to 1.0 M. In other embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be from 0.01 M to 0.1 M. In certain embodiments, in other embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be from 0.02 to 0.05 M. In certain embodiments, the concentration of the bulky organic cation salt in the bulky organic cation salt solution can be about 0.05 M. The bulky organic cation salt solution can be deposited on a lead halide thin film formed after deposition of the lead halide precursor ink or the thin film precursor ink. In other embodiments, the bulky organic cation salt solution can be deposited on the perovskite precursor thin film after deposition of the second salt solution.

[0141]

[0174] Finally, the substrate having the perovskite material precursor thin film can be annealed. By annealing the substrate, the lead salt precursor and the second salt precursor can be converted to a perovskite material (e.g., FAPbI 3 , GAPb(SCN) 3 , FASnI 3 ) having a surface passivation layer of a bulky organic cation. The annealing can be performed in various atmospheres, such as atmospheric pressure (e.g., about 1 atm depending on altitude and atmospheric conditions) or a pressure lower than atmospheric pressure (e.g., 1 mTorr to 500 mTorr). The annealing atmosphere can be ambient air, a controlled humidity environment (e.g., 0 to 100 g of H 2 O / m 3 ), pure argon, pure nitrogen, pure oxygen, pure hydrogen, pure helium, pure neon, pure krypton, pure CO 2, or any combination of the above gases. The controlled humidity environment may include an environment where the absolute humidity or % relative humidity is maintained at a fixed value, or an environment where the absolute humidity or % relative humidity changes according to a predetermined set point or a predetermined function. In certain embodiments, annealing may be performed in a controlled humidity environment where the relative humidity is between 0% and 50%. In other embodiments, annealing may be performed in a controlled humidity environment containing a gas of 2 O / m 3 or more and 20 g H 2 O / m 3 or less. In certain embodiments, annealing can be performed at a temperature of 50 °C to 300 °C. Unless otherwise specified, any annealing or deposition process described herein can be carried out under the above conditions.

[0142]

[0175] For example, in certain embodiments, FAPbI 3 perovskite materials can be formed by the following process. First, a lead(II) halide precursor with a molar ratio of PbI 2 to PbCl 2 of about 90:10 dissolved in anhydrous DMF can be deposited on a substrate by spin coating or slot die printing. The lead halide precursor ink can be dried in a substantially water-free atmosphere, i.e., at a relative humidity of less than 30% or less than 17 g H 2 O / m 3 for about 1 hour (+15 minutes) to form a thin film. The thin film can then be thermally annealed at about 50 °C (+10 °C) for about 10 minutes. In other embodiments, the lead halide precursor may be deposited by inkjet printing, gravure printing, screen printing, blade coating, sputtering, PE-CVD, atomic layer deposition, thermal evaporation, or spray coating. Next, a 1-butylammonium salt solution with a concentration of 0.05 M in isopropyl alcohol may be formed on the lead halide thin film. The substrate may be at a relative humidity of about 25% (about 4 - 7 g of H 2 O / m 3air) and annealed between about 100 °C and 200 °C to form a formamidinium lead iodide (FAPbI with a surface layer of 1-butylammonium 3 ) perovskite material can be formed. In another embodiment, the 1-butylammonium salt solution may be deposited on a thin film formed after deposition of the formamidinium iodide precursor. In another embodiment, the 1-butylammonium salt solution can be combined with the lead halide precursor ink prior to deposition of the lead halide precursor ink. In yet another embodiment, the 1-butylammonium salt solution can be combined with the formamidinium iodide precursor prior to deposition of the formamidinium iodide precursor. In yet another embodiment, the 1-butylammonium salt solution may be deposited on the thin film after deposition of the formamidinium iodide precursor and before annealing the thin film and the substrate. In yet another embodiment, the 1-butylammonium salt solution may be deposited on the thin film after annealing the thin film and the substrate.

[0143]

[0176] In other embodiments, when the above method is used with a lead iodide (II) solution, a cesium iodide solution, a methylammonium iodide (MA) salt solution, and a 1-butylammonium salt solution, a perovskite material having a surface layer of 1-butylammonium of the formula Cs i MA 1-i PbI 3 (where i represents a number between 0 and 1) may be obtained. As another example, by using a lead iodide (II) solution, a rubidium iodide solution, a formamidinium iodide (FA) salt solution, and a 1-butylammonium salt solution, a perovskite material having a surface layer of 1-butylammonium of the formula Rb i FA 1-i PbI 3 (where i represents a number between 0 and 1) can be obtained. As another example, when a lead iodide (II) solution, a cesium iodide solution, a formamidinium iodide (FA) salt solution, and a 1-butylammonium salt solution are used, a perovskite material having a surface layer of 1-butylammonium of the formula Cs i FA 1-i PbI 3(where i represents a number between 0 and 1) A perovskite material with a surface layer of 1-butylammonium can be obtained. As another example, using a lead(II) iodide solution, a potassium iodide solution, a formamidinium iodide (FA) salt solution, and a 1-butylammonium salt solution, the formula K i FA 1-i PbI 3 (where i represents a number between 0 and 1) A perovskite material with a surface layer of 1-butylammonium can be obtained. As another example, by using a lead(II) iodide solution, a sodium iodide solution, a formamidinium iodide (FA) salt solution, and a 1-butylammonium salt solution, the formula Na i FA 1-i PbI 3 (where i represents a number between 0 and 1) A perovskite material with a surface layer of 1-butylammonium can be obtained. As another example, using a lead(II) iodide - lead(II) chloride mixed solution, a cesium iodide solution, a formamidinium iodide (FA) salt solution, and a 1-butylammonium salt solution, the formula Cs i FA 1-i PbI 3-y Cl y (where i represents a number between 0 and 1 and y represents a number between 0 and 3) A perovskite material with a surface layer of 1-butylammonium can be obtained.

[0144]

[0177] In other embodiments, the FAPbI 3 perovskite material can be formed by the following process. First, a lead(II) halide precursor with a molar ratio of PbI 2 to PbCl 2 of about 90:10 dissolved in anhydrous DMF can be deposited on a substrate by spin coating or slot die printing. The lead(II) halide precursor ink is in a substantially water-free atmosphere, that is, a relative humidity of less than 30% or 17 g H 2 O / m 3It can be dried for less than about 1 hour (+15 minutes) to form a thin film. The thin film can then be thermally annealed at about 50 °C (+10 °C) for about 10 minutes. In other embodiments, the lead halide precursor may be deposited by inkjet printing, gravure printing, screen printing, sputtering, PE-CVD, atomic layer deposition, thermal evaporation, or spray coating. Next, a formamidinium iodide precursor containing formamidinium iodide dissolved in anhydrous isopropyl alcohol at a concentration of 15-60 mg / mL can be deposited on the lead halide thin film by spin coating or blade coating. In other embodiments, the formamidinium iodide precursor may be deposited by inkjet printing, gravure printing, screen printing, slot die printing, sputtering, PE-CVD, atomic layer deposition, blade coating, thermal evaporation, or spray coating. After depositing the lead halide precursor and the formamidinium iodide precursor, a benzylammonium salt solution having a concentration of 0.04 M in isopropyl alcohol may be deposited on the perovskite material precursor thin film. Then, the substrate is annealed at a relative humidity of about 25% (about 4-7 g of H 2 O / m 3 air) and between about 125 °C and 200 °C to form a formamidinium lead iodide (FAPbI 3 ) perovskite material. In certain embodiments, the benzylammonium salt solution may be deposited on the lead halide thin film prior to deposition of the formamidinium iodide precursor. In other embodiments, the benzylammonium salt solution may be combined with the lead halide precursor ink prior to deposition of the lead halide precursor ink. In still other embodiments, the benzylammonium salt solution may be combined with the formamidinium iodide precursor prior to deposition of the formamidinium iodide precursor. In certain embodiments, the resulting perovskite material may have a cubic crystal structure for the bulk material away from the surface. The presence of a bulky organic cation near the surface of the perovskite material may result in a non-cubic crystal structure near the surface of the perovskite material.

[0145]

[0178] In other embodiments, the above method may be used with lead (II) iodide solution, cesium iodide solution, methylammonium iodide (MA) salt solution and benzylammonium salt solution to obtain a perovskite material with a benzylammonium surface layer of formula Cs i MA 1-i PbI 3 , where i represents a number between 0 and 1. As another example, by using lead(II) iodide solution, rubidium iodide solution, formamidinium iodide (FA) salt solution and benzylammonium salt solution, a perovskite material with the formula Rb i FA 1-i PbI 3 (where i represents a number between 0 and 1) and a benzylammonium surface layer can be obtained. As another example, a lead(II) iodide solution, a cesium iodide solution, a formamidinium iodide (FA) salt solution, and a benzylammonium salt solution can be used to obtain a benzylammonium surface layer perovskite material of the formula Cs i FA 1-i PbI 3 , where i is a number between 0 and 1. As another example, a lead(II) iodide solution, a potassium iodide solution, and a formamidinium iodide (FA) salt solution and a benzylammonium salt solution can be used to obtain a benzylammonium surface layer perovskite material of the formula K i FA 1-i PbI 3 , where i is a number between 0 and 1. As another example, by using lead(II) iodide solution, sodium iodide solution, formamidinium iodide (FA) salt solution and benzylammonium salt solution, a perovskite material with a benzylammonium surface layer of the formula Na i FA 1-i PbI 3 (where i represents a number between 0 and 1) can be obtained. As another example, by using lead(II) iodide-lead(II) chloride mixed solution, cesium iodide solution, formamidinium iodide (FA) salt solution and benzylammonium salt solution, a perovskite material with a benzylammonium surface layer of the formula Cs i FA 1-i PbI3-y Cl y (wherein i represents a number between 0 and 1, and y represents a number between 0 and 3) A perovskite material having a surface layer that is benzylammonium can be obtained.

[0146]

[0179] A method for producing a perovskite material using benzylammonium is described below. First, PbI 2 , PbCl 2 , and cesium iodide (CsI) are dissolved in a mixture of DMF and DMSO solvents to prepare a lead iodide precursor ink. For the preparation of the lead iodide precursor, CsI is dissolved in DMSO to prepare a 1.5 M CsI / DMSO solution. The CsI / DMSO solution can be prepared, in certain embodiments, by stirring CsI in DMSO at a rate of 1.5 mmol of CsI per 1.0 mL of anhydrous DMSO for 1 hour to 2.5 hours at room temperature. Next, the above CsI solution is added to a solution of PbI 2 , PbCl 2 , and anhydrous DMF solvent to form a 1.28 M Pb 2+ solution in which the ratio of Cs to Pb is 1:10 and the ratio of I to Cl is 9:1. In certain embodiments, the 1.28 M Pb 2+ solution can be prepared by adding the CsI solution to a container containing 1.26 mmol of PbI 2 , 0.14 mmol of PbCl 2 , and 1.0 mL of anhydrous DMF solvent, for each 93.8 μL of the CsI solution. The Pb 2+ solution is mixed at a temperature of 50 °C to 100 °C for 1.5 hours to 2.5 hours and then cooled to form a lead iodide precursor ink. In certain embodiments, the Pb 2+ solution can be cooled by stirring at 85 °C for 2 hours and then stirring for 1 hour in a room temperature environment. In certain embodiments, the lead iodide precursor ink may be filtered prior to deposition of the lead iodide precursor ink. In certain embodiments, a 0.2 μm filter can be used to filter the lead iodide precursor ink.

[0147]

[0180] The formamidinium iodide (FAI) and benzylammonium iodide (BzAI) solutions are prepared by dissolving the FAI and BzAI salts in anhydrous isopropanol (IPA) to form a 0.2 M FAI solution and a 0.05 M BzAI solution, respectively. In certain embodiments, both the FAI and BzAI solutions can be maintained at 75 °C during the following coating process.

[0148]

[0181] Next, after depositing the lead iodide precursor ink on the substrate, it is annealed to form a lead iodide film. In certain embodiments, the lead iodide precursor ink maintained at 45 °C can be blade-coated onto a substrate coated with a nickel oxide (NiO) thin film layer and then annealed at 50 °C for 10 minutes to form a lead iodide film.

[0149]

[0182] Next, to form the perovskite material layer, first the lead iodide film is primed once with the BzAI solution and then primed with 3 coats of the FAI solution. After the deposition of each coating of the BzAI solution and the FAI solution, the coating is dried before depositing the following coating. In certain embodiments, both the BzAI and FAI solutions can be maintained at 45 °C during the deposition of each coat. After the third FAI coat is deposited, the substrate and the coating can be annealed to form the perovskite material layer. In certain embodiments, after the third FAI is deposited, the substrate is immediately heated to 157 °C for 5 minutes to anneal the perovskite material layer.

[0150]

[0183] The above method may have certain advantages. For example, depositing the BzAI solution on the lead iodide film prior to the deposition of the FAI solution can provide an intermediate template for the growth of the 2D perovskite material. BzAI may react with the lead iodide thin film to form an intermediate 2D perovskite material phase. When it reacts with FAI after the deposition of the FAI solution, the BzA+ cations in the 2D phase are completely or partially replaced by FA+ cations, and 3D FAPbI 3 can provide an intermediate template for the growth of the perovskite material. BzAI may react with the lead iodide thin film to form an intermediate 2D perovskite material phase. When it reacts with FAI after the deposition of the FAI solution, the BzA+ cations in the 2D phase are completely or partially replaced by FA+ cations, and 3D FAPbI 3A framework is formed. Further, BzAI can also passivate crystal defects in the 3D FAPbI 3 perovskite material. The photoluminescence intensity of the FAPbI 3 thin film formed by the above process is brighter (higher) than that of the FAPbI 3 thin film formed by a process without BzAI. FIG. 31 shows both the optical (absorbance) image and the photoluminescence image of the perovskite material photovoltaic device 3105 generated without adding BzAI and the perovskite material photovoltaic device 3110 generated using BzAI, as described herein. FIG. 31 shows that the optical image of the perovskite material photovoltaic device 3110 is dark, indicating a higher light absorbance, and the photoluminescence image of the perovskite material photovoltaic device 3110 is brighter than that of the perovskite material photovoltaic device 3105. Further, it has been observed that the power output is greater from the perovskite material photovoltaic device incorporating BzAI. FIG. 32 shows the power output curve 3205 corresponding to a photovoltaic device without BzAI, such as the photovoltaic device 3105, and the power output curve 3210 corresponding to a photovoltaic device containing BzAI, such as the photovoltaic device 3110, as described herein. The power output measurements shown in FIG. 32 were measured for 180 seconds at the maximum power point under 100 mW / cm 2 AM1.5G illumination, with 30 seconds of dark measurement intervening. As can be seen from FIG. 32, the photovoltaic device incorporating BzAI during manufacturing has a power per unit area (16.0 mW / cm 2 ), 770 mV, and 19.5 mA / cm 2 ) greater than that of a photovoltaic device without BzAI (15.0 mW / cm 2 ), (785 mV), and a current per unit area (20.3 mA / cm 2) increases. FIG. 33 shows the current-voltage (I-V) scans 3320 of a perovskite material photovoltaic device manufactured without BzAI, labeled as the sample "5r" line, and a perovskite material photovoltaic device manufactured with BzAI, labeled as the sample "10r" line. As can be seen from FIG. 33, the perovskite material photovoltaic device manufactured using BzAI generates a larger current over a certain range of bias voltages than the perovskite material photovoltaic device manufactured without using BzAI. Further, FIG. 34 shows box plots regarding the open-circuit voltage, short-circuit current density, fill factor, and power conversion efficiency for six perovskite material photovoltaic devices manufactured without using BzAI (sample 5, r = reverse scan, f = forward scan, and s = steady-state measurement) and six perovskite material photovoltaic devices manufactured using BzAI (sample 10). FIG. 35 shows the external quantum efficiency of six perovskite material photovoltaic devices manufactured without BzAI (plot 3505) and six perovskite material photovoltaic devices manufactured with BzAI (plot 3510). Each EQE curve in FIG. 35 is integrated to estimate the Jsc at mA / cm 2 and this indicates that the perovskite material device manufactured with BzAI shows a higher Jsc (area under the EQE curve) than the perovskite material device manufactured without BzAI. Finally, FIG. 36 shows the admittance spectroscopy plot 3605 for a perovskite material photovoltaic device manufactured without BzAI and the admittance spectroscopy plot 3610 for a perovskite material photovoltaic device manufactured with BzAI. The admittance spectroscopy plot 3610 shows suppressed ion migration for the sample device containing benzylammonium compared to the admittance spectroscopy plot 3605 for the sample device without benzylammonium. Excessive ion migration is known to have a harmful effect on the performance and durability of perovskite material devices, indicating that incorporating benzylammonium into perovskite material photovoltaic devices can improve the performance and durability of the devices.

[0151]

[0184] Diammonium butane cation reinforced perovskite The incorporation of 1,4-diammonium butane or other polyammonium organic compounds below into the crystal structure of the perovskite material can improve the properties of the material. In one embodiment, FAPbI of 1,4-diammonium butane as described below 3 The addition to the perovskite can provide a perovskite material with advantageous properties. In certain embodiments, 1,4-diammonium butane can be incorporated into a perovskite material that utilizes a 1,4-diammonium butane salt in place of a bulky organic cation salt in the above method, and the addition of the 1,4-diammonium butane salt (or other organic polyammonium salts described herein) can occur at any step (stage) of the perovskite manufacturing method where the addition of a bulky organic cation salt is described above. Incorporating an organic cation such as 1,4-diammonium butane into the crystal structure of the perovskite material may deviate from the "ideal" stoichiometry of the perovskite materials disclosed herein. For example, due to the inclusion of such organic cations, the perovskite material may be represented by a formula that is either substoichiometric or superstoichiometric with respect to the formula FAPbI described herein 3 In this case, the general formula of the perovskite material can be represented as CxMyXz. Here, x, y, and z are real numbers.

[0152]

[0185] In one embodiment, the 1,4-diammonium butane salt solution may be added to the lead halide precursor ink solution before deposition. In certain embodiments, the 1,4-diammonium butane salt can be added to the lead halide precursor ink solution at a concentration of 0.001 mol% to 50 mol%. In certain embodiments, the 1,4-diammonium butane salt can be added to the lead halide precursor ink solution at a concentration of 0.1 mol% to 20 mol%. In certain embodiments, the 1,4-diammonium butane salt can be added to the lead halide precursor ink solution at a concentration of 1 mol% to 10 mol%.

[0153]

[0186] In other embodiments, a 1,4-diammonium butane salt may be added to the formamidinium salt solution before contacting the formamidinium salt solution with the lead halide precursor thin film as described above. In certain embodiments, the 1,4-diammonium butane salt can be added to the formamidinium iodide salt solution at a concentration of 0.001 mol% to 50 mol%. In certain embodiments, the 1,4-diammonium butane salt can be added to the formamidinium iodide salt solution at a concentration of 0.1 mol% to 20 mol%. In certain embodiments, the 1,4-diammonium butane salt can be added to the formamidinium iodide salt solution at a concentration of 1 mol% to 10 mol%.

[0154]

[0187] In other embodiments, the 1,4-diammonium butane salt precursor solution can be deposited on the lead halide thin film formed after the deposition of the lead halide precursor ink or on the perovskite precursor thin film after the deposition of the formamidinium salt solution. In certain embodiments, the concentration of the 1,4-diammonium butane salt precursor solution can be from 0.001 mol% to 50 mol%. In certain embodiments, the concentration of the 1,4-diammonium butane salt precursor solution can be from 0.1 mol% to 20 mol%. In certain embodiments, the concentration of the 1,4-diammonium butane salt precursor solution can be from 1 mol% to 10 mol%.

[0155]

[0188] An exemplary method of depositing a perovskite material containing 1,4-diammonium butane includes depositing a lead salt precursor on a substrate to form a lead salt thin film, and depositing an organic cation salt precursor containing a first organic cation salt on the lead salt thin film to form a perovskite precursor thin film. The lead salt precursor or the organic cation salt precursor may include a 1,4-diammonium butane salt, or a 1,4-diammonium butane salt precursor may be deposited on the lead salt thin film or the perovskite precursor thin film. Finally, the substrate and the perovskite precursor thin film may be annealed to form a perovskite material containing 1,4-diammonium butane. The lead salt precursor and the organic cation salt precursor may include any solution described herein for producing a perovskite thin film.

[0156]

[0189] The length between the ammonium groups of 1,4-diammonium butane is approximately the same as the length between formamidinium cations in the crystal lattice of the formamidinium lead iodide perovskite material. Thus, 1,4-diammonium butane can replace two formamidinium ions during the formation of the FAPbI 3 material. In other embodiments, other alkyl polyammonium salts can be added to the lead halide precursor ink during the formation of the perovskite material. For example, 1,8-diammonium octane, bis(4-aminobutyl)amine, and tris(4-aminobutyl)amine can be added. Further, polyammonium polycations containing 1,4-diammonium butane can provide the same advantages as the above-mentioned bulky organic cations by a similar mechanism with respect to the bulky organic cations.

[0157]

[0190] FIG. 13 is a schematic diagram showing the effect that the addition of 1,4-diammonium butane salt during the process of manufacturing a perovskite material may have on the resulting perovskite 7000. As shown in FIG. 13, the 1,4-diammonium butane cation 7020 can replace two formamidinium cations 7010 in the perovskite material crystal lattice. FAPbI 3In perovskite, the spacing between formamidinium cations is approximately 6.35 Å. The length of the 1,4-diammonium butane cation is approximately 6.28 Å, with a difference of only 0.07 Å. Therefore, the 1,4-diammonium butane cation can be substituted into the perovskite crystal lattice without significantly changing the properties or structure of the perovskite crystal lattice. In certain embodiments, the addition of the 1,4-diammonium butane cation to the perovskite material can enhance the properties and stability of the perovskite material. The 1,4-diammonium butane cation acts as a rigid structure within the perovskite material, enhancing its structural and chemical durability. For example, in certain embodiments, the perovskite material with the 1,4-diammonium butane cation added can exhibit excellent dry heat stability compared to the perovskite material without the 1,4-diammonium butane cation added. Furthermore, the perovskite material with the 1,4-diammonium butane cation added may show a blue shift in the emission spectrum of the perovskite material. In certain embodiments, the 1,4-diammonium butane cation can be added to the formamidinium salt solution at a concentration of 0 to 20 mol%. In other embodiments, the 1,4-diammonium butane cation can be added to the formamidinium salt solution at a concentration of 1 to 5 mol%. In certain embodiments, the 1,4-diammonium butane cation was added to the formamidinium salt solution at a concentration of 5 mol%.

[0158]

[0191] Experimentally, it has been shown that even when adding up to 20% of 1,4-diammonium butane to the perovskite material, the lattice constant does not shift significantly. Figure 14 shows the X-ray diffraction peaks of perovskite with 0 mol%, 5 mol%, 10 mol% and 20 mol% of 1,4-diammonium butane iodide (「DABI」). At each concentration, the main peaks are at the same position, indicating that the lattice parameter of the perovskite material does not change significantly when adding 1,4-diammonium butane at a concentration of 0 mol% - 20 mol%. When adding 1,4-diammonium butane, diffraction with a weak intensity below 13° 2θ with Cu-Kα radiation occurs, indicating that there is a small amount of 2D or layered perovskite phase.

[0159]

[0192] Figure 15 provides images of perovskite samples of 0 mol, 1 mol, 2.5 mol% and 5 mol% exposed to a temperature of 85 °C for 7 days at 0% relative humidity. The perovskite material with 0 mol% DABI shows a significant bright color after 1 day and further significant yellowing after 7 days. This indicates that the perovskite material with 0 mol% DABI deteriorated significantly after being exposed to the test conditions for 1 day. All the perovskite material samples of 1 mol%, 2.5 mol% and 5 mol% remained dark after 7 days, indicating that adding 1 mol% of DABI significantly enhances the so-called 「dry heat」 stability of the perovskite material.

[0160]

[0193] Furthermore, when adding 1,4-diammonium butane to the perovskite material, a slight blue shift may occur in the photoluminescence observed in the perovskite material compared to the perovskite material without 1,4-diammonium butane. This blue shift is the result of the passivation of trap states in the perovskite material caused by the addition of 1,4-diammonium butane. This blue shift indicates that adding 1,4-diammonium butane to the perovskite material reduces the defect density of the crystal lattice of the perovskite material without changing the crystal structure of the perovskite material. For example, FAPbI without 1,4-diammonium butane 3Compared with the perovskite material, FAPbI with 20 mol% of 1,4-diammonium butane added 3 The resulting blue shift observed in the perovskite material is a change of 0.014 eV from 1.538 eV without 1,4-diammonium butane to 1.552 eV with 20 mol% of 1,4-diammonium butane.

[0161]

[0194] In other embodiments, other ammonium complexes can be added during the formation of the perovskite material. For example, FIG. 16 shows three ammonium compounds, 1,8-diammonium octane, bis(4-aminobutyl)-ammonium, and tris(4-aminobutyl)-ammonium, which can be added to the perovskite material in the same manner as described above with respect to the 1,4-diammonium butane cation. 1,8-diammonium octane, when introduced during the formation of the perovskite material as described above, can occupy the space of two formamidinium cations (the "A site") in the perovskite material crystal lattice. Bis(4-aminobutyl)-ammonium, when introduced during the formation of the perovskite material as described above, may occupy the space of three A sites in the perovskite material crystal lattice. Tris(4-aminobutyl)-ammonium, when introduced during the formation of the perovskite material as described above, may occupy the space of four A sites in the perovskite material crystal lattice. FIGS. 16A - 16C provide schematic diagrams of the incorporation of the three ammonium compounds shown in FIG. 16 into the perovskite material crystal lattice. FIG. 16A is a schematic diagram of the incorporation of 1,8-diammonium octane into the perovskite material crystal lattice 7100. As shown in FIG. 16A, the 1,8-diammonium octane cation 7120 may replace two formamidinium cations 7110 in the perovskite material crystal lattice. FIG. 16B is of FAPbI 3 in the perovskite material crystal lattice. 3 in the perovskite material crystal lattice. 3 in the perovskite material crystal lattice. FIGS. 16A - 16C provide schematic diagrams of the incorporation of the three ammonium compounds shown in FIG. 16 into the perovskite material crystal lattice. FIG. 16A is a schematic diagram of the incorporation of 1,8-diammonium octane into the perovskite material crystal lattice 7100. As shown in FIG. 16A, the 1,8-diammonium octane cation 7120 may replace two formamidinium cations 7110 in the perovskite material crystal lattice. FIG. 16B is a schematic diagram of the incorporation of bis(4-aminobutyl)-ammonium into the perovskite material crystal lattice 7100. As shown in FIG. 16B, the bis(4-aminobutyl)-ammonium cation 7130 may occupy three A sites in the perovskite material crystal lattice. FIG. 16C is a schematic diagram of the incorporation of tris(4-aminobutyl)-ammonium into the perovskite material crystal lattice 7100. As shown in FIG. 16C, the tris(4-aminobutyl)-ammonium cation 7140 may occupy four A sites in the perovskite material crystal lattice. 3 in the perovskite material crystal lattice. 3 A schematic diagram of the incorporation of 1,8-diammonium octane into the perovskite material crystal lattice 7100. As shown in FIG. 16A, the 1,8-diammonium octane cation 7120 may replace two formamidinium cations 7110 in the perovskite material crystal lattice. FIG. 16B is of FAPbI 3Schematic diagram of the incorporation of bis(4-aminobutyl)-ammonium into the perovskite material crystal lattice 7200. As shown in FIG. 16B, the bis(4-aminobutyl)-ammonium cation 7220 may replace three formamidinium cations 7210 in the perovskite material crystal lattice. FIG. 16C shows FAPbI 3 Schematic diagram of the incorporation of tris(4-aminobutyl)-ammonium into the perovskite material crystal lattice 7300. As shown in FIG. 16c, the tris(4-aminobutyl)-ammonium cation 7320 may replace four formamidinium cations 7310 in the perovskite material crystal lattice. In other embodiments, an alkyldiammonium complex having a carbon chain with 2 to 20 carbon atoms can be added to the perovskite material. In certain embodiments, a combination of ammonium complexes can be added to the perovskite material.

[0162]

[0195] Cross-linked interface layer In certain embodiments, the PV device may include one or more crosslinked interfacial layers. The crosslinked interfacial layer may be physically and chemically more robust than the non-crosslinked interfacial layer. For example, the crosslinked interfacial layer may be harder, stronger, denser, less permeable to liquids and / or gases, and less reactive than the non-crosslinked interfacial layer. Further, the crosslinked interfacial layer may have electrical properties different from those of the non-crosslinked interfacial layer. The crosslinked interfacial layer may include a dielectric polymer, a crosslinked polymer, a crosslinked fullerene, and a composite of a fullerene and nanoparticles. In certain embodiments, the crosslinked interfacial layer may be deposited as an IFL between an electrode such as IFL 1030 and IFL 1050 in FIG. 1 and the photoactive layer.

[0163]

[0196] The crosslinked interfacial layer may include one or more of a polymer, a fullerene, and a fullerene derivative.

[0164]

[0197] Examples of polymers include the following:

[0198] Polyvinyl arenes, including ortho, para, or meta isomers and di, tri, tetra, and penta-substituted derivatives, as well as polystyrene, polyvinyl naphthalene, polyvinyl phenol (e.g., poly(4-vinylphenol)), polyvinyl aniline, polyvinyl benzoic acid, polyvinyl haloarene (e.g., poly(4-chlorostyrene)), polyvinyl pyridine (e.g., poly(4-vinylpyridine)), polyvinyl thiophene, polyvinyl pyrrole, polyvinyl furan, and polyvinyl pyrrolidone, etc.

[0165]

[0199] Examples of polyarenes include polyacenaphthylene, polyphenylene oxide, polyphenylene sulfide, polyaniline, polyfuran, polythiophene, polypyrrole, etc.

[0166]

[0200] Examples of polyvinyl alkanes include polyolefins (e.g., polyethylene, polypropylene, polyacetylene), polyvinyl alcohol, polyvinyl acetate, polyvinyl halide, polyacrylic acid, polymethacrylic acid, polymethyl methacrylate, polyacrylonitrile, polyvinyl cyclohexane, polyvinyl amine, and polyvinyl thiol, etc.

[0167]

[0201] Examples of fullerenes include C60, C70, and C84.

[0168]

[0202] Examples of substituted fullerenes include azafullerene (C60-n Nn), borafullerene (C60-n Bn), azaborafullerene (C60-(n+m) Nn Bm).

[0169]

[0203] Examples of endohedral fullerenes (endo fullerenes) include metal fullerenes (M@C 60 , where M is any transition metal), trimetaspherea carbon nanomaterials (M 3 N@C 80 , where M is a lanthanide or any transition metal), M 2 @C 80(M is any transition metal) and non-metal doped fullerenes (e.g., Ng@C60, Ng = He, Ne, Ar, Kr, Xe (noble gas) and H 2 @C 60 ) include endohedral fullerenes (endo fullerenes).

[0170]

[0204] Examples of exohedral fullerenes include fullerols (e.g., C 60 (OH) n (n = 1 - 60)), alkyl fullerenes (e.g., C 60 Rn (n = 1 - 60)), halogen fullerenes (e.g., C 60 Xn (X = F, Cl, Br, or I, n = 1 - 60)), hydro fullerenes (e.g., C 60 Hn (n = 1 - 60)), methanofullerene derivatives (e.g., Bingel derivatives including dialkyl ester methanofullerenes (C 60 C(CO 2 ) 2 (R = alkyl or aryl group)), dialkynylmethanofullerenes (C 60 C(C 2 R) 2 ), fullerenedihydrorophyrols (C 60 CR 2 NCCOR), Prato derivatives: C 60 C 2 NR (R = alkyl or aryl group phenyl C61)-methyl butyrate (PCMA), phenyl-C61-methyl butyrate (PCMB), transition metal fullerene complexes, and fulleriod (methanoannulene) (ring-opened fullerene derivative).

[0171]

[0205] In one embodiment, the crosslinked interfacial layer may be composed of fullerenes crosslinked by one or more polymers. Examples of crosslinkable polymers include polystyrene, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM); poly(4-vinylphenol); [6,6]-phenyl-C61-butyric acid or other poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), and poly(3,4,5-trihydroxystyrene), which may be substituted in place of poly(4-vinylphenol), polyvinylaryl.

[0172]

[0206] In one embodiment, the crosslinked interfacial layer may include a mixture of polystyrene and a silane monomer. As described herein, silanes may include any hydro-, hydroxy-, halo-, alkyl-, alkenyl-, alkynyl-, cyclo-, aromatic-, alkoxyalkyl-, alkoxyalkenyl-, alkoxyaromatic-, haloalkyl-, haloalkenyl-, haloalkyne-, and haloaromatic silanes. In other embodiments, instead of silanes, boranes, amines, phosphines, dicarboxylic acids, disulfide bonds, and cyclophanes and cyclophane derivatives may be used for crosslinking the IFL. FIG. 37 is a diagram showing the structure of a crosslinked interfacial layer composed of polystyrene and a halosilylalkane before and after crosslinking. In the embodiment shown in FIG. 37, 1,6-bis(trichlorosilyl)hexane acts to crosslink the polystyrene polymer molecules in the interfacial layer. However, in other embodiments, any alkane or arene (e.g., benzene) may be used instead of the hexane shown, and any halogen or alkoxy group (e.g., methoxy, ethoxy) may be used instead of the chloro group.

[0173]

[0207] In other embodiments, the crosslinked interfacial layer may comprise a mixture of polystyrene, silane, and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). In other embodiments, instead of silane, borane, amine, phosphine, dicarboxylic acid, disulfide bond, and cyclophane and cyclophane derivatives may be used for crosslinking the IFL. FIG. 38 shows the structure of a crosslinked interfacial layer composed of PCBM, polystyrene, and halosilylalkane before and after crosslinking. FIG. 38 shows an alkylsilane that acts to crosslink the polystyrene polymer molecules in the interfacial layer while immobilizing the PCBM molecules within the crosslinked polymer interfacial layer.

[0174]

[0208] In one embodiment, the crosslinked interfacial layer may comprise a mixture of poly(4-vinylphenol) and a silane monomer. In other embodiments, instead of silane, borane, amine, phosphine, dicarboxylic acid, disulfide bond, and cyclophane and cyclophane derivatives may be used for crosslinking the IFL. In other embodiments, instead of poly(4-vinylphenol), poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), and poly(3,4,5-trihydroxystyrene) are substituted. FIG. 39 shows the structure of a crosslinked interfacial layer composed of poly(4-vinylphenol) and halosilylalkane before and after crosslinking. FIG. 39 shows a halosilylalkane that acts to crosslink the poly(4-vinylphenol) polymer molecules in the interfacial layer.

[0175]

[0209] In other embodiments, the crosslinked interfacial layer may comprise a mixture of poly(4-vinylphenol), silane, and PCBM. In other embodiments, instead of silane, borane, amine, phosphine, dicarboxylic acid, disulfide bond, and cyclophane and cyclophane derivatives can be used for crosslinking the IFL. In other embodiments, instead of poly(4-vinylphenol), poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), and poly(3,4,5-trihydroxystyrene) are substituted. Figure 40 shows the structure of a crosslinked interfacial layer composed of PCBM, poly(4-vinylphenol), and halosilylalkane before and after crosslinking. Figure 40 shows a halosilylalkane that acts to crosslink the poly(4-vinylphenol) polymer molecules in the interfacial layer while immobilizing the PCBM molecules within the crosslinked polymer interfacial layer.

[0176]

[0210] In other embodiments, the crosslinked interfacial layer may comprise a mixture of polystyrene, silane, and [6,6]-phenyl-C61-butyric acid (PCBA). In other embodiments, instead of silane, borane, amine, phosphine, dicarboxylic acid, disulfide bond, and cyclophane and cyclophane derivatives can be used for crosslinking the IFL. Figure 41 shows the structure of a crosslinked interfacial layer composed of PCBA, polystyrene, and halosilylalkane before and after crosslinking. Figure 41 shows a halosilylalkane that acts to crosslink the polystyrene polymer molecules and PCBA molecules in the interfacial layer.

[0177]

[0211] In other embodiments, the crosslinked interfacial layer may comprise a mixture of poly(4-vinylphenol), silane, and PCBA. In other embodiments, instead of silane, borane, amine, phosphine, dicarboxylic acid, disulfide bond, and cyclophane and cyclophane derivatives may be used for crosslinking the IFL. In other embodiments, instead of poly(4-vinylphenol), poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), and poly(3,4,5-trihydroxystyrene) are substituted. FIG. 42 shows the structure of a crosslinked interfacial layer composed of PCBA, poly(4-vinylphenol), and halosilylalkane before and after crosslinking. FIG. 42 shows a halosilylalkane that acts to crosslink poly(4-vinylphenol) polymer molecules and PCBA molecules in the interfacial layer. As shown in FIG. 42, the PCBA molecules are completely immobilized within the crosslinked polymer interfacial layer by bonding to the silane groups of the halosilylalkane compound.

[0178]

[0212] A method for depositing a crosslinked fullerene interfacial layer is described below. The initial cyclophane is converted to a dimethylbenzene radical. Next, the dimethylbenzene radical is deposited on a substrate together with fullerene, such that a crosslinked interfacial layer with fullerene is crosslinked by one or more dimethylbenzene molecules. In certain embodiments, the fullerene and the dimethylbenzene radical may be deposited by chemical vapor deposition, vapor deposition, or plasma vapor deposition. When deposited on a perovskite layer, the interfacial layer deposited by this method may form a conformal coating along the surface of the perovskite material. The fullerene and the crosslinked dimethylbenzene polymer fill the surface of the perovskite irregularly, thereby increasing the degree of contact between the interfacial layer and the perovskite layer.

[0179]

[0213] Another method for depositing a cross-linked fullerene interfacial layer is described below. The first fullerene is functionalized with alkyl hydroxide groups on the surface of the fullerene. Next, the functionalized fullerene is deposited on a substrate. In certain embodiments, the functionalized fullerene can be deposited on the perovskite layer of a photovoltaic device. The functionalized fullerene can be deposited by methods including, but not limited to, spin coating, slot die printing, chemical vapor deposition, thermal evaporation, sputtering, atomic layer deposition, extrusion, and gravure printing. Next, the fullerene coating can be treated with a silane compound to form a cross-linked silicon-fullerene interfacial layer. The silane compound can include any hydro-, hydroxy-, halo-, alkyl-, alkenyl-, alkynyl-, cyclo-, aromatic-, alkoxylalkyl-, alkoxyalkenyl-, alkoxyaromatic-, haloalkyl-, haloalkenyl-, haloalkynyl-, haloalkyne-, and haloaromatic silane. In other embodiments, instead of silane, borane, amine, phosphine, dicarboxylic acid, disulfide bond, and cyclophane and cyclophane derivatives can be used for cross-linking the IFL. In certain embodiments, the silane compound can be a halosilylalkane. The halosilylalkane can be, in certain embodiments, 1,6-bis(trichlorosilyl)hexane. Such a silicon-fullerene cross-linked interfacial layer may have advantageous electrical properties of the fullerene enhanced by the physical properties of silicon. For example, the silicon-fullerene interfacial layer can have water resistance and flexibility while maintaining the desirable electrical properties of the fullerene.

[0180]

[0214] Yet another method for depositing a cross-linked fullerene interfacial layer is described below. First, a polymer is dissolved in a solvent to form a polymer solution. In certain embodiments, the solvent used to dissolve the polymer may include alcohols, aryl solvents, chlorinated solvents, ketones, nitriles, alkane solvents, formamides, esters, and combinations thereof. The concentration of the polymer in the solution can range from about 1 uM to about 1 M. In certain embodiments, the concentration of the polymer in the solution can range from about 1 mM to about 10 M. Next, fullerenes are added to the polymer solution. In certain embodiments, the fullerenes can be added directly as a solid into the polymer solution or first dissolved in a solvent (e.g., benzene, chlorobenzene, dichlorobenzene, toluene, chloroform) and then added to the polymer solution. In certain embodiments, the fullerene concentration after addition can range from about 1 uM to about 10 M. In certain embodiments, the fullerene concentration in the solution can range from about 1 mM to about 1 M. Next, a cross-linking agent is added directly to the polymer solution either as a liquid or a solid. In certain embodiments, the cross-linking agent can be dissolved in a solvent and then added to the polymer solution. The solvents used to dissolve the cross-linking agent may include alcohols, aryl solvents, chlorinated solvents, acetone, acetonitrile, alkyl solvents, formamides, esters, and combinations thereof. In certain embodiments, the cross-linking agent may be added to the polymer solution prior to the addition of fullerenes. The cross-linking agent concentration after addition to the fullerenes and polymer solution can range from about 1 uM to about 10 M. In certain embodiments, the cross-linking agent concentration in the solution can range from about 1 mM to about 1 M. In certain embodiments, this solution can be prepared in a substantially air-free (i.e., oxygen- or water-free) environment that can avoid premature cross-linking and solidification of the cross-linked interfacial layer ink. In certain embodiments, the cross-linking agent may be added immediately prior to application of the cross-linked interfacial layer ink. The polymers described herein can include any polymer disclosed in the present disclosure, and the fullerenes may include any fullerene or fullerene derivative disclosed in the present disclosure. Alternatively, the polymer may be added to the fullerene and / or cross-linking agent solution as described above.

[0181]

[0215] The crosslinked interfacial layer ink of the present disclosure can be deposited by blade coating, spin coating, slot die printing, inkjet printing, gravure printing, screen printing, sputtering, spray coating, drop casting, or any other solution-based deposition technique described in the present disclosure. In certain embodiments, the deposition may be performed in an ambient atmosphere, a controlled atmosphere, and / or an atmosphere substantially free of water, carbon dioxide, and oxygen. The wet layer may be dried ambiently or at an elevated temperature (e.g., 0 - 250 °C). The wet layer or dry layer may be exposed to UV radiation to facilitate crosslinking. In certain embodiments, the crosslinking agent may require UV irradiation to crosslink.

[0182]

[0216] The crosslinked interfacial layer can be deposited directly on the perovskite material layer, on a layer pre-deposited on the perovskite layer (e.g., fullerene, dielectric material, semiconductor material, any interfacial layer described in the present disclosure), or on the conductive substrate of the present disclosure. When the crosslinked interfacial layer is deposited on the conductive substrate, the perovskite material can be deposited directly on the crosslinked interfacial layer or one or more additional interfacial layers can be deposited on the crosslinked interfacial layer before the perovskite material is deposited by any technique described herein.

[0183]

[0217] In other embodiments, various different fullerenes, polymers, and crosslinking agents can be used instead. For example, FIG. 43 shows an example using polyhydroxyl fullerene as the fullerene, FIG. 44 shows an example using formaldehyde as the crosslinking agent, and FIG. 45 shows an example using poly(4-chlorostyrene) as the polymer and sodium sulfide as the crosslinking agent.

[0184]

[0218] Accordingly, the present invention is well adapted to attain the above objects and advantages, as well as those inherent therein. The embodiments disclosed above are merely exemplary. This is because the present invention can be modified and implemented in different but equivalent ways that will be apparent to those skilled in the art having the benefits of the teachings herein. Furthermore, the details of the configurations or designs described herein are not limited by anything other than the scope of the appended claims. Therefore, it is obvious that the specific exemplary embodiments disclosed above can be changed or modified, and all such changes are considered to be within the scope and spirit of the present invention. In particular, any range of values disclosed herein (such as "about a to about b", or equivalently "about a - b", or equivalently "about a - b") is to be understood as referring to the power set of each range of values (the set of all subsets), and describes all ranges subsumed within the broader range of values. Also, the terms in the claims have their plain and ordinary meaning unless the patentee provides a separate express and clear definition otherwise.

Claims

1. fullerene or fullerene derivative, A crosslinking agent, and one or more polymers, wherein said crosslinker comprises a silane, said silane being a halosylalkane.

2. 2. The crosslinked interfacial layer composition of claim 1, wherein the fullerene or fullerene derivative is selected from the group consisting of general fullerenes, substituted fullerenes, endohedral fullerenes, exohedral fullerenes, and any combination thereof.

3. 2. The crosslinked interfacial layer composition of claim 1, wherein the fullerene or fullerene derivative is selected from the group consisting of [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C61-butyric acid, polyhydroxyl fullerene, and any combination thereof.

4. The crosslinked interfacial layer composition of claim 1 , wherein the one or more polymers comprise a polyvinylaryl.

5. 2. The crosslinked interfacial layer composition of claim 1, wherein the one or more polymers are selected from the group consisting of 4-(polyvinylphenol), poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), poly(3,4,5-trihydroxystyrene), poly(4-chlorostyrene), and any combination thereof.

6. 10. The crosslinked interfacial layer composition of claim 1, wherein the one or more polymers are selected from the group consisting of polystyrene, polyvinylnaphthalene, polyvinylphenol, polyvinylaniline, polyvinylbenzoic acid, polyvinylhaloarenes, polyvinylpyridine, polyvinylthiophene, polyvinylpyrrole, polyvinylfuran, polyvinylpyrrolidone, and any combination thereof.

7. 10. The crosslinked interfacial layer composition of claim 1, wherein the one or more polymers are selected from the group consisting of polyacenaphthylene, polyphenylene oxide, polyphenylene sulfide, polyaniline, polyfuran, polythiophene, polypyrrole, and any combination thereof.

8. 10. The crosslinked interfacial layer composition of claim 1, wherein the one or more polymers are selected from the group consisting of polyolefins, polyvinyl alcohols, polyvinyl acetates, polyvinyl halides, polyacrylic acids, polymethacrylates, polymethyl methacrylates, polyacrylonitriles, polyvinyl cyclohexanes, polyvinyl amines, polyvinyl thiols, and any combination thereof.

9. A photoactive material comprising a perovskite material; and Fullerene or a fullerene derivative, and One or more polymers a crosslinked interfacial layer comprising: A photovoltaic device comprising: A photovoltaic device, wherein the fullerene or fullerene derivative, the one or more polymers, or both, are crosslinked with a crosslinking agent, wherein the crosslinking agent comprises a silane, and the silane is a halosilalkane.

10. The photovoltaic device of claim 9, wherein the fullerene or fullerene derivative is selected from the group consisting of [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C61-butyric acid, polyhydroxyl fullerene, and any combination thereof.

11. The photovoltaic device of claim 9, wherein the fullerene or fullerene derivative is selected from the group consisting of general fullerenes, substituted fullerenes, endohedral fullerenes, exohedral fullerenes, and any combination thereof.

12. The photovoltaic device of claim 9, wherein the one or more polymers include a polyvinyl aryl.

13. The photovoltaic device of claim 9, wherein the one or more polymers are selected from the group consisting of 4-(polyvinylphenol), poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), poly(3,4,5-trihydroxystyrene), poly(4-chlorostyrene), and any combination thereof.

14. The photovoltaic device of claim 9, wherein the one or more polymers are selected from the group consisting of polystyrene, polyvinylnaphthalene, polyvinylphenol, polyvinylaniline, polyvinylbenzoic acid, polyvinylhaloarenes, polyvinylpyridine, polyvinylthiophene, polyvinylpyrrole, polyvinylfuran, polyvinylpyrrolidone, and any combination thereof.

15. The photovoltaic device of claim 9, wherein the one or more polymers are selected from the group consisting of polyacenaphthylene, polyphenylene oxide, polyphenylene sulfide, polyaniline, polyfuran, polythiophene, polypyrrole, and any combination thereof.

16. The photovoltaic device of claim 9, wherein the one or more polymers are selected from the group consisting of polyolefins, polyvinyl alcohols, polyvinyl acetates, polyvinyl halides, polyacrylic acids, polymethacrylates, polymethyl methacrylates, polyacrylonitriles, polyvinyl cyclohexanes, polyvinyl amines, polyvinyl thiols, and any combination thereof.

17. 1. A method for manufacturing a perovskite material photovoltaic device comprising: depositing a layer comprising fullerene or a fullerene derivative onto the perovskite material; depositing a cross-linking agent onto the perovskite material or the layer comprising fullerene or fullerene derivative; and depositing one or more polymers onto the perovskite material or the layer comprising fullerene or fullerene derivative; wherein the crosslinking agent comprises a silane, and the silane is a halosylalkane.

18. 20. The method of claim 17, further comprising functionalizing the fullerene or fullerene derivative with an alkyl hydroxide.

19. The method of claim 17 , wherein the one or more polymers comprise a polyvinylaryl.

20. 18. The method of claim 17, wherein the one or more polymers are selected from the group consisting of 4-(polyvinylphenol), poly(3-vinylphenol), poly(2-vinylphenol), poly(3,5-dihydroxystyrene), poly(3,4-dihydroxystyrene), poly(3,4,5-trihydroxystyrene), poly(4-chlorostyrene), and any combination thereof.

21. The method of claim 17, wherein the fullerene or fullerene derivative is selected from the group consisting of [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C61-butyric acid, polyhydroxyl fullerene, and any combination thereof.

22. The method of claim 17, wherein the fullerene or fullerene derivative is selected from the group consisting of general fullerenes, substituted fullerenes, endohedral fullerenes, exohedral fullerenes, and any combination thereof.

23. 18. The method of claim 17, wherein the one or more polymers are selected from the group consisting of polystyrene, polyvinylnaphthalene, polyvinylphenol, polyvinylaniline, polyvinylbenzoic acid, polyvinylhaloarenes, polyvinylpyridine, polyvinylthiophene, polyvinylpyrrole, polyvinylfuran, polyvinylpyrrolidone, and any combination thereof.

24. 20. The method of claim 17, wherein the one or more polymers are selected from the group consisting of polyolefins, polyvinyl alcohols, polyvinyl acetates, polyvinyl halides, polyacrylic acids, polymethacrylates, polymethyl methacrylates, polyacrylonitriles, polyvinyl cyclohexanes, polyvinyl amines, polyvinyl thiols, and any combination thereof.

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