Hybrid perovskite material processing

Abstract

A method of preparing a photoactive perovskite material.SOLUTION: Contacting lead halide with a first solvent to dissolve the lead halide and form a lead halide solution; contacting a Group 1 metal halide with a second solvent; Dissolving the Group 1 metal halide to form a Group 1 metal halide solution; and contacting the lead halide solution with the Group 1 metal halide solution to form the thin film precursor ink; depositing the thin film precursor ink on a substrate; drying the thin film precursor ink to form a thin film; annealing the thin film; and immersing the thin film in a salt solution comprising a third solvent and a salt selected from a specified group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The use of photovoltaics (PV) to generate electricity from solar energy or radiation can offer many advantages, including power source, low or zero emissions, power production independent of the power grid, durable physical construction (no moving parts), stable and reliable system, modular construction, relatively quick installation, safe manufacture and use, and good public opinion and acceptance of use. [Background technology]

[0002] The features and advantages of the present disclosure will be readily apparent to those skilled in the art, and numerous modifications may be made by those skilled in the art, all of which are within the spirit of the present invention. [Brief explanation of the drawings]

[0003] [Figure 1] FIG. 1 is an illustration of a DSSC design showing various layers of the DSSC according to some embodiments of the present disclosure. [Figure 2] FIG. 1 is another illustration of a DSSC design showing various layers of the DSSC according to some embodiments of the present disclosure. [Figure 3] FIG. 1 is an exemplary illustration of a BHJ device design according to some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of a typical photovoltaic cell including an active layer according to some embodiments of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of an exemplary solid state DSSC device according to some embodiments of the present disclosure. [Figure 6] FIG. 1 is a stylized diagram depicting components of an exemplary PV device according to some embodiments of the present disclosure. [Figure 7] FIG. 1 is a stylized diagram illustrating components of an exemplary PV device according to some embodiments of the present disclosure. [Figure 8]FIG. 1 is a stylized diagram illustrating components of an exemplary PV device according to some embodiments of the present disclosure. [Figure 9] FIG. 1 is a stylized diagram illustrating components of an exemplary PV device according to some embodiments of the present disclosure. Summary of the Invention [Problem to be solved by the invention]

[0004] Prior art documents Non-patent literature (Non-patent document 1) Hyosung Choi, et al., “Cesium-doped methylammonium lead iodide perovskite light absorber for hybrid solar cells”, Nano Energy, (2014) 7, 80-82 (Non-Patent Document 2) Bertrand Philippe, et al., “Chemical Distribution of Multiple Cation (Rb + ,Cs + ,MA + ,and FA + ) Perovskite Materials by Photoelectron Spectroscopy”,Chemistry of Materials,March 30,2017 Detailed Description of the Preferred Embodiments Improvements in various aspects of PV technologies that are compatible with organic, inorganic, and / or hybrid PVs promise to further lower the costs of both OPVs and other PVs. For example, some solar cells, such as solid-state dye-sensitized solar cells, can utilize novel cost-effective and highly stable alternative components such as solid-state charge transport materials (or, colloquially, "solid-state electrolytes"). Furthermore, various types of solar cells can advantageously include interfacial and other materials that are more cost-effective and durable than currently existing conventional options, among other benefits.

[0005] This disclosure relates generally to compositions of matter, devices, and methods of using materials in photovoltaic cells in generating electrical energy from solar radiation. More specifically, this disclosure relates to photoactive and other compositions of matter, as well as devices, methods of use, and the formation of such compositions of matter.

[0006] Examples of these compositions of matter may include materials that may be suitable for use as, for example, hole-transport materials, and / or interfacial layers, dyes, and / or other elements of PV devices. Such compounds can be deployed in a variety of PV devices, such as heterojunction cells (e.g., bilayer and bulk), hybrid cells (e.g., organics with CH3NH3HPbI3, ZnO nanorods, or PbS quantum dots), and dye-sensitized solar cells (DSSCs). The latter DSSCs exist in three forms: solvent-based electrolytes, ionic liquid electrolytes, and solid-state hole transporters (or solid-state DSSCs, or SS-DSSCs). SS-DSSC structures according to some embodiments may be substantially free of electrolyte, but rather contain hole-transporting materials such as spiro-OMeTAD, CsSnI3, and other active materials.

[0007] Some or all of the materials according to some embodiments of the present disclosure may be advantageously used in any organic or other electronic device, some examples of which may include, but are not limited to, batteries, field-effect transistors (FETs), light-emitting diodes (LEDs), nonlinear optical devices, memristors, capacitors, rectifiers, and / or rectifying antennas (rectennas). [Means for solving the problem]

[0008] In some embodiments, the present disclosure may provide PV and other similar devices (e.g., batteries, hybrid PV batteries, multi-junction PVs, FETs, LEDs, etc.). Such devices may, in some embodiments, include improved active materials, interfacial layers, and / or one or more perovskite materials. The perovskite materials may be incorporated into one or more various aspects of PV or other devices. Perovskite materials according to some embodiments may be of the general formula CMX3, where: C comprises one or more cations (e.g., amines, ammonium, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds); M comprises one or more metals (examples include Fe, Co, Ni, Cu, Sn, Pb, Bi, Ge, Ti, and Zr); and X comprises one or more anions. Perovskite materials according to various embodiments are discussed in more detail below. DETAILED DESCRIPTION OF THE INVENTION

[0009] Photovoltaic cells and other electronic devices Some PV embodiments can be described with reference to various exemplary depictions of solar cells, such as those shown in Figures 1, 3, 4, and 5. For example, an exemplary PV architecture according to some embodiments may be substantially in the form of substrate-anode-IFL-active layer-IFL-cathode. The active layer of some embodiments may be photoactive and / or include a photoactive material. Other layers and materials may be utilized within the cell as known in the art. Furthermore, it should be noted that the use of the term "active layer" is not meant to explicitly or implicitly limit the properties of other layers in any way. For example, in some embodiments, one or both IFLs may be active, as long as they are semiconducting. With particular reference to Figure 4, a stylized generic PV cell 2610 is depicted, illustrating the highly interfacial nature of some layers within the PV. PV 2610 represents a generic architecture applicable to some PV devices, such as DSSC PV embodiments. The PV cell 2610 includes a transparent layer 2612 of glass (or a material similarly transparent to solar radiation) that allows solar radiation 2614 to pass through the layer. The transparent layer in some embodiments is also referred to as a substrate (e.g., similar to substrate layer 1507 in FIG. 1 ) and may include any one or more of a variety of rigid or flexible materials, such as glass, polyethylene, PET, Kapton, quartz, aluminum foil, gold foil, or steel. The photoactive layer 2616 is composed of an electron donor or p-type material 2618 and / or an electron acceptor or n-type material 2620. The active layer, or photoactive layer 2616, as shown in FIG. 4, is sandwiched between two conductive electrode layers 2622 and 2624. In FIG. 4, electrode layer 2622 is an ITO material. As mentioned above, the active layer in some embodiments does not necessarily need to be photoactive, but in the device shown in FIG. 4, it is. Electrode layer 2624 is an aluminum material. Other materials may be used as known in the art.Cell 2610 also includes an interfacial layer (IFL) 2626, shown in the example of FIG. 4 as a PEDOT:PSS material. The IFL can assist in charge separation. In some embodiments, IFL 2626 can include a photoactive organic compound according to the present disclosure as a self-assembled monolayer (SAM) or as a thin film. In other embodiments, IFL 2626 can include a bilayer of thin film coatings, as described in more detail below. IFL 2627 can be present on the aluminum cathode side of the device. In some embodiments, IFL 2627 on the aluminum cathode side of the device can also include a photoactive organic compound according to the present disclosure as a self-assembled monolayer (SAM) or as a thin film, or instead include a photoactive organic compound. In other embodiments, IFL 2627 on the aluminum cathode side of the device can include a bilayer of thin film coatings, or instead include a bilayer of thin film coatings (also described in more detail below). The IFL in some embodiments may be semiconductive in character and may be either p-type or n-type. In some embodiments, the IFL on the cathode side of the device (e.g., IFL 2627 shown in FIG. 4) may be p-type and the IFL on the anode side of the device (e.g., IFL 2626 shown in FIG. 4) 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 2610 is attached to leads 2630 and a discharge unit 2632, such as a battery.

[0010] Yet another embodiment can be described with reference to FIG. 3 , which shows a stylized BHJ device design and includes a glass substrate 2401; an ITO (tin-doped indium oxide) electrode 2402; an interface layer (IFL) 2403; a photoactive layer 2404; and a LiF / Al cathode 2405. The materials of the BHJ structure referenced are merely examples, and any other BHJ structure known in the art can be used consistent with this disclosure. In some embodiments, the photoactive layer 2404 can include one or more materials that the active layer or photoactive layer 2616 of the device of FIG. 4 can include.

[0011] FIG. 1 is a simplified diagram of a DSSC PV according to some embodiments, and is referred to herein for purposes of illustrating the assembly of such a PV. The example DSSC shown in FIG. 1 can be constructed as follows: An electrode layer 1506 (shown as fluorine-doped tin oxide, FTO) is deposited on a substrate layer 1507 (shown as glass). A mesoporous layer ML 1505 (which in some embodiments can be TiO) is deposited on the electrode layer 1506, and the photoelectrode (now including the substrate layer 1507, electrode layer 1506, and mesoporous layer 1505) is then immersed in a solvent and dye (not shown). This leaves the dye 1504 bound to the surface of the ML. A separate counter electrode is fabricated, including the substrate layer 1501 (also shown as glass) and the electrode layer 1502 (shown as Pt / FTO). The photoelectrode and counter electrode are assembled by sandwiching various layers 1502-1506 between two substrate layers 1501 and 1507, as shown in FIG. 1, with the electrode layers 1502 and 1506 serving as the cathode and anode, respectively. An electrolyte layer 1503 is deposited after the dye layer 1504 or directly on the completed photoelectrode through a device opening, typically pre-drilled by sandblasting in the counter electrode substrate 1501. The cell may also be attached to a lead and discharge unit, such as a battery (not shown). The substrate layer 1507 and electrode layer 1506, and / or the substrate layer 1501 and electrode layer 1502, should be sufficiently transparent to allow solar radiation to pass through to the photoactive dye 1504. In some embodiments, the counter electrode and / or photoelectrode may be rigid, while either or both may be flexible. The substrate layer in various embodiments may include any one or more of glass, polyethylene, PET, Kapton, quartz, aluminum foil, gold foil, and steel.In certain embodiments, the DSSC may further include a light harvesting layer 1601, as shown in FIG. 2, to scatter incident light and increase the path length of the light through the photoactive layer of the device (thereby increasing the likelihood that the light will be absorbed by the photoactive layer).

[0012] In other embodiments, the present disclosure provides solid-state DSSCs. Solid-state DSSCs according to some embodiments may offer advantages such as a lack of leakage and / or corrosion issues that affect DSSCs containing liquid electrolytes. Furthermore, solid-state charge carriers may provide faster device physics (e.g., faster charge transport). Additionally, solid-state electrolytes may, in some embodiments, be photoactive and thus contribute to the power derived from solid-state DSSC devices.

[0013] Some examples of solid-state DSSCs can be described with reference to FIG. 5, which is a schematic diagram of a typical solid-state DSSC. For example, similar to the exemplary solar cell shown in FIG. 4, an active layer consisting of first and second active (e.g., conductive and / or semiconductive) materials (2810 and 2815, respectively) is sandwiched between electrodes 2805 and 2820 (shown in FIG. 5 as Pt / FTO and FTO, respectively). In the embodiment shown in FIG. 5, first active material 2810 is a p-type active material and includes a solid electrolyte. In certain embodiments, first active material 2810 may include an organic material such as spiro-OMeTAD and / or poly(3-hexylthiophene), an inorganic binary, ternary, quaternary, or higher complex, any solid semiconductive material, or any combination thereof. In some embodiments, the first active material can additionally or alternatively include an oxide and / or sulfide and / or selenide and / or iodide (e.g., CsSnI). Thus, for example, the first active material of some embodiments can include a solid-state p-type material that can include copper indium sulfide, and in some embodiments, copper indium gallium selenide. The second active material 2815 shown in FIG. 5 is an n-type active material and includes dye-coated TiO. In some embodiments, the second active material can also include an organic material such as spiro-OMeTAD, an inorganic binary, ternary, quaternary, or higher complex, or any combination thereof. In some embodiments, the second active material can include an oxide such as alumina, and / or can include a sulfide, and / or can include a selenide. Thus, in some embodiments, the second active material can include copper indium sulfide, and in some embodiments, copper indium gallium selenide. The second active material 2815 of some embodiments can comprise a mesoporous layer. Furthermore, in addition to being active, either or both of the first and second active materials 2810 and 2815 can be photoactive.In other embodiments (not shown in FIG. 5 ), the second active material can include a solid electrolyte. Additionally, in embodiments in which either the first and second active materials 2810 and 2815 include a solid electrolyte, the PV device can lack an effective amount of liquid electrolyte. Although shown and referenced in FIG. 5 as p-type, the solid-state layer (e.g., the first active material including the solid electrolyte) can instead be an n-type semiconductor in some embodiments. In such embodiments, the dye-coated second active material (e.g., TiO (or other mesoporous material) as shown in FIG. 5 ) can be a p-type semiconductive material (as opposed to the n-type semiconductive material shown and discussed with respect to FIG. 5 ).

[0014] Substrate layers 2801 and 2825 (both shown as glass in FIG. 5 ) form the respective exterior top and bottom layers of the exemplary cell of FIG. 5 . These layers can comprise any material sufficiently transparent to allow solar radiation to pass through to the active / photoactive layers, including first and second active and / or photoactive materials 2810 and 2815, such as glass, polyethylene, PET, Kapton, quartz, aluminum foil, gold foil, and / or steel. Furthermore, in the embodiment shown in FIG. 5 , electrode 2805 (shown as Pt / FTO) is the cathode, and electrode 2820 is the anode. Similar to the exemplary solar cell depicted in FIG. 4 , solar radiation passes through substrate layer 2825 and electrode 2820 to enter the active layer, where at least a portion of the solar radiation is absorbed, generating one or more excitons that enable electricity generation.

[0015] Solid-state DSSCs according to some embodiments can be constructed in a manner substantially similar to that described above with respect to the DSSC shown in Figure 1. In the embodiment shown in Figure 5, p-type active material 2810 corresponds to electrolyte 1503 in Figure 1; n-type active material 2815 corresponds to both dye 1504 and ML in Figure 1; electrodes 2805 and 2820 correspond to electrode layers 1502 and 1520, respectively, in Figure 1; and substrate layers 2801 and 2825 correspond to substrate layers 1501 and 1507, respectively.

[0016] Various embodiments of the present disclosure provide improved materials and / or designs for various aspects of solar cells and other devices, including, among other things, active materials (including hole-transport and / or electron-transport layers), interfacial layers, and overall device design.

[0017] interfacial layer The present disclosure provides, in some embodiments, advantageous materials and designs for one or more interfacial layers in a PV, including thin-coat IFLs, which can be utilized in one or more IFLs of a PV according to various embodiments discussed herein.

[0018] First, as previously mentioned, one or more IFLs (e.g., one or both of IFLs 2626 and 2627 shown in FIG. 4 ) can include a photoactive organic compound of the present disclosure as a self-assembled monolayer (SAM) or as a thin film. When a photoactive organic compound of the present disclosure is applied as a SAM, the photoactive organic compound can include a binding group. The photoactive organic compound can be covalently or otherwise bound to the surface of either or both of the anode and cathode via the binding group. In some embodiments, the binding group can include one or more of COOH, SiX (where X can be any moiety suitable for forming a tertiary silicon compound, such as Si(OR) and SiCl), SO, PO, H, OH, CHX (where X can include a Group 17 halide), and O. The binding groups can be covalently or otherwise attached to electron-withdrawing moieties, electron donor moieties, and / or core moieties. The binding groups can be attached to the electrode surface in such a way as to form a directional organized layer of a single molecule (or, in some embodiments, multiple molecules) in thickness (e.g., when multiple photoactive organic compounds are attached to the anode and / or cathode). As mentioned, the SAMs can be attached via covalent interactions, but in some embodiments, they can be attached via ionic, hydrogen bonding, and / or dispersion force (i.e., van der Waals) interactions. Furthermore, in certain embodiments, upon exposure to light, the SAMs can enter zwitterionic excited states, thereby generating highly polarized IFLs capable of directing charge carriers from the active layer to the electrode (e.g., either the anode or cathode). This enhanced charge carrier injection can be achieved in some embodiments by electronically poling the cross-section of the active layer and thus increasing the charge carrier drift velocity towards their respective electrodes (e.g., holes to the anode; electrons to the cathode).Molecules for anode applications in some embodiments can include tunable compounds that include a primary electron donor moiety bonded to a core moiety, which in turn is bonded to an electron-withdrawing moiety, which in turn is bonded to a linking group. In cathode applications in some embodiments, IFL molecules can include an electron-poor moiety bonded to a core moiety, which in turn is bonded to an electron-donor moiety, which in turn is bonded to a linking group. When photoactive organic compounds are utilized as IFLs in such embodiments, they can retain photoactive properties, although in some embodiments they need not be photoactive.

[0019] In addition to or instead of a photoactive organic compound SAM IFL, a PV according to some embodiments can include a thin interfacial layer (“thin-coat interfacial layer” or “thin-coat IFL”) coated on at least a portion of either the first or second active material of such embodiments (e.g., first or second active material 2810 or 2815 as shown in FIG. 5). At least a portion of the thin-coat IFL can then, in turn, be coated with a dye. The thin-coat IFL can be either n-type or p-type; in some embodiments, the thin-coat IFL can be of the same type as the underlying material (e.g., TiO or other mesoporous material, such as TiO of second active material 2815). The second active material can include TiO coated with a thin-coat IFL comprising alumina (e.g., AlO) (not shown in FIG. 5), which is then coated with a dye. References herein to TiO and / or titania are not intended to limit the ratio of tin to oxide in such tin oxide compounds described herein. That is, titania compounds can contain titanium in any one or more of its various oxidation states (e.g., titanium I, titanium II, titanium III, titanium IV), and therefore various embodiments can include stoichiometric and / or non-stoichiometric amounts of titanium and oxide. Thus, various embodiments can include TiO (instead of or in addition to TiO). x O ywhere x can be an integer or non-integer between 1 and 100. In some embodiments, x can be between about 0.5 and 3. Similarly, y can be between about 1.5 and 4 (and also need not be an integer). Thus, some embodiments can include, for example, TiO2 and / or Ti2O3. Additionally, titania in whatever ratio or combination between titanium and oxides can, in some embodiments, be comprised of any one or more crystalline structures, including any one or more of anatase, rutile, and amorphous.

[0020] Other exemplary metal oxides for use in the thin-film-coated IFL of some embodiments can include semiconducting metal oxides, such as ZnO, ZrO, NbO, SrTiO, TaO, NiO, WO, VO, or MoO. An exemplary embodiment in which the second (e.g., n-type) active material includes TiO coated with a thin-film-coated IFL including AlO can be formed with a precursor, such as Al(NO)·xH0, or any other material suitable for depositing AlO onto TiO, followed by thermal annealing and dye coating. In an exemplary embodiment in which a MoO coating is used instead, the coating can be formed with a precursor such as NaMoO·2H0; whereas a VO coating according to some embodiments can be formed with a precursor such as NaVO; and a WO coating according to some embodiments can be formed with a precursor such as NaWO·H0. The concentration of the precursor (e.g., Al(NO3)3·xH2O) can affect the thickness of the final film (here, composed of Al2O3) deposited on TiO2 or other active materials. Therefore, varying the precursor concentration can be a way to control the final film thickness. For example, a larger film thickness can result from a larger precursor concentration. A larger film thickness does not necessarily result in a larger PCE (power conversion efficiency) in a PV device including a metal oxide coating. Thus, in some embodiments, a method can include coating a TiO2 (or other mesoporous) layer with a precursor having a concentration in the range of about 0.5 to 10.0 mM; another embodiment can include coating the layer with a precursor having a concentration in the range of about 2.0 to 6.0 mM; or, in other embodiments, about 2.5 to 5.5 mM.

[0021] Furthermore, although reference is made herein to Al2O3 and / or alumina, it should be noted that various ratios of aluminum to oxygen may be used in forming the alumina. Thus, while some embodiments discussed herein are described with reference to Al2O3, such description is not intended to dictate the required ratio of aluminum in oxygen. Rather, embodiments may be used to describe alumina in which each Al x O y (where x can be any value between about 1 and 100, integer or non-integer). In some embodiments, x can be between about 1 and 3 (and also need not be an integer). Similarly, y can be any value between 0.1 and 100, integer or non-integer. In some embodiments, y can be between 2 and 4 (and also need not be an integer). Additionally, in various embodiments, Al x O y Various crystalline forms of alumina may be present, such as alpha, gamma, and / or amorphous forms of alumina.

[0022] Similarly, although referred to herein as MoO3, WO3, and V2O5, such compounds may alternatively or additionally be referred to as Mo x O y , W x O y and V x O y can be expressed as: Mo x O y and W x O y For each of the above, x can be any value, integer or non-integer, between about 0.5 and 100; in some embodiments, x(it) 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 some embodiments, y can be between about 1 and 4. x O ywhere x can be any value, integer or non-integer, between about 0.5 and 100; in some embodiments, x(it) 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(it) can be any value, integer or non-integer, between about 1 and 10.

[0023] Similarly, references to CsSnI in some exemplary embodiments herein are not intended to limit the ratios of component elements of cesium-tin-iodine compounds according to various embodiments. Some embodiments may include stoichiometric and / or non-stoichiometric amounts of tin and iodide, and thus, such embodiments may alternatively or additionally include various non-stoichiometric ratios of cesium, tin, and iodine, e.g., Cs x Sn y I z In some embodiments, x can be any value between 0.1 and 100, integer or non-integer. In some embodiments, x can be between about 0.5 and 1.5 (and also need not be an integer). Similarly, y can be any value between 0.1 and 100, integer or non-integer. In some embodiments, y can be between about 0.5 and 1.5 (and also need not be an integer). Similarly, z can be any value between 0.1 and 100, integer or non-integer. In some embodiments, z can be between about 2.5 and 3.5. Additionally, CsSnI3 may be doped or blended with other materials, such as SnF2. The ratio of CsSnI3:SnF2 ranges from 0.1:1 to 100:1, including all values ​​(integer and non-integer) therebetween.

[0024] Additionally, the thin-film-coated IFL can include a bilayer. Thus, returning to the example where the thin-film-coated IFL includes a metal oxide (such as alumina), the thin-film-coated IFL can include TiO plus a metal oxide. Such thin-film-coated IFLs may have a greater ability to resist charge recombination compared to mesoporous TiO or other active materials alone. Furthermore, in forming the TiO layer, according to some embodiments of the present disclosure, a secondary TiO coating is often required to provide sufficient physical interconnection of the TiO particles. Coating a bilayer thin-film-coated IFL on mesoporous TiO (or other mesoporous active materials) can include a combination of coating with a compound including both a metal oxide and TiCl, resulting in a bilayer thin-film-coated IFL including a combination of a metal oxide and a secondary TiO coating, which may provide improved performance over using either material on its own.

[0025] The thin-film-coated IFLs and methods for coating them on TiO2 described above can be utilized in some embodiments in DSSCs that include liquid electrolytes. Thus, returning to the example of the thin-film-coated IFL, and referring back to, for example, Figure 1, the DSSC of Figure 1 can further include the thin-film-coated IFL described above coated on mesoporous layer 1505 (i.e., the thin-film-coated IFL would be interposed between mesoporous layer 1505 and dye 1504).

[0026] In some embodiments, the thin-film coated IFL discussed above in the context of DSSCs can be used in any interfacial layer of semiconductor devices such as PVs (e.g., hybrid PVs or other PVs), field-effect transistors, light-emitting diodes, nonlinear optical devices, memristors, capacitors, rectifiers, rectifying antennas, etc. Additionally, the thin-film coated IFL of some embodiments can be utilized in any of a variety of devices in combination with other compounds discussed in this disclosure. Various embodiments of the present disclosure include the following: solid hole transport materials and additives (e.g., in some embodiments, chenodeoxycholic acid or 1,8-diiodooctane); This includes, but is not limited to, one or more of the following:

[0027] additives As previously mentioned, PV and other devices according to some embodiments may include additives (e.g., any one or more of acetic acid, propanoic acid, trifluoroacetic acid, chenodeoxycholic acid, deoxycholic acid, 1,8-diiodooctane, and 1,8-dithiooctane). Such additives may be applied as a pretreatment immediately prior to dye immersion or mixed with the dye in various ratios to form the immersion solution. These additives may function to increase dye solubility and prevent dye molecule clustering, in some cases, for example, by blocking open active sites and inducing molecular order among the dye molecules. They may be used with any suitable dye, including photoactive compounds according to various embodiments of the present disclosure as discussed herein.

[0028] Perovskite Materials The perovskite material may be incorporated into one or more aspects of a PV or other device. Perovskite materials according to some embodiments have the general formula C w M y X z wherein: C comprises one or more cations (e.g., amines, ammonium, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds); M comprises one or more metals (including Fe, Co, Ni, Cu, Ag, Au, Tl, In, Sb, Sn, Pb, Bi, Ga, Ge, Ti, and Zn); X comprises one or more anions; and w, y, and z represent real numbers from 1 to 20. In some embodiments, C can include one or more organic cations. In some embodiments, each organic cation C can be larger than each metal M, and each anion X can be capable of binding to both the cation C and the metal M. In certain embodiments, the perovskite material can have the formula CMX3.

[0029] In certain embodiments, C is ammonium, a group of the general formula [NR4] + where the R groups can be the same or different groups. Suitable R groups are: Methyl, ethyl, propyl, butyl, pentyl groups or their isomers; Any alkane, alkene, or alkyne CxHy (where x=1-20, y=1-42, cyclic, branched, or straight chain); alkyl halides, CxHyXz (wherein x=1 to 20, y=0 to 42, z=1 to 42, and X=F, Cl, Br, or I); Any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes in which at least one nitrogen is contained within 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 phosphorous-containing group (phosphate); 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 alpha, beta, gamma, and larger derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valerate); Any silicon-containing group (e.g., siloxane); and Any alkoxy or -OCxHy group, where x=0 to 20 and y=1 to 42; Including (but not limited to):

[0030] In certain embodiments, C is formamidinium and has the general formula [RNCRNR] + wherein the R groups may be the same or different. Suitable R groups are: hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or isomers thereof; Any alkane, alkene, or alkyne CxHy (where x=1-20, y=1-42, cyclic, branched, or straight chain); alkyl halides, CxHyXz (wherein x=1 to 20, y=0 to 42, z=1 to 42, and X=F, Cl, Br, or I); Any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes in which at least one nitrogen is contained within the ring (e.g., imidazole, benzimidazole, dihydropyrimidine, (azolidinylidenemethyl)pyrrolidine, triazole); Any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); Any nitrogen-containing group (nitroxide, amine); Any phosphorous-containing group (phosphate); 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 alpha, beta, gamma, and larger derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valerate); Any silicon-containing group (e.g., siloxane); and Any alkoxy or -OCxHy group, where x=0 to 20 and y=1 to 42; Including (but not limited to):

[0031] Formula 1 [ka]

[0032] Formula 1 is a compound having the general formula [R2NCRNR2] as shown above. + The structure of the formamidinium cation having the formula:

[0033] Formula 2 shows exemplary structures of some formamidinium cations that can serve as the cation "C" in perovskite materials.

[0034] formula 2 [ka]

[0035] In certain embodiments, C is guanidinium and has the general formula [(RN)C=NR] + where the R groups may be the same or different. Suitable R groups are: hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or isomers thereof; Any alkane, alkene, or alkyne CxHy (where x=1-20, y=1-42, cyclic, branched, or straight chain); alkyl halides, CxHyXz (wherein x=1 to 20, y=0 to 42, z=1 to 42, and X=F, Cl, Br, or I); Any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes in which at least one nitrogen is contained within the ring (e.g., octahydropyrimido[1,2-a]pyrimidine, pyrimido[1,2-a]pyrimidine, hexahydroimidazo[1,2-a]imidazole, hexahydropyrimidin-2-imine); Any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); Any nitrogen-containing group (nitroxide, amine); Any phosphorous-containing group (phosphate); 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 alpha, beta, gamma, and larger derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valerate); Any silicon-containing group (e.g., siloxane); and Any alkoxy or -OCxHy group, where x=0 to 20 and y=1 to 42; Including (but not limited to):

[0036] Formula 3 [ka]

[0037] Formula 3 is the general formula [(R2N)2C=NR2] as shown above. + Formula 4 shows examples of the structures of some guanidinium cations that can serve as the cation "C" in perovskite materials.

[0038] formula 4 [ka] [ka]

[0039] In certain embodiments, C is an ethenetetramine cation having the general formula [(RN)C=C(NR)]+ where the R groups may be the same or different. Suitable R groups are: hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or isomers thereof; Any alkane, alkene, or alkyne CxHy (where x=1-20, y=1-42, cyclic, branched, or straight chain); alkyl halides, CxHyXz (wherein x=1 to 20, y=0 to 42, z=1 to 42, and X=F, Cl, Br, or I); Any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes in which at least one nitrogen is contained within the ring (e.g., 2-hexahydropyrimidin-2-ylidenehexahydropyrimidine, octahydropyrazino[2,3-b]pyrazine, pyrazino[2,3-b]pyrazine, quinoxalino[2,3-b]quinoxaline); Any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); Any nitrogen-containing group (nitroxide, amine); Any phosphorous-containing group (phosphate); 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 alpha, beta, gamma, and larger derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valerate); Any silicon-containing group (e.g., siloxane); and Any alkoxy or -OCxHy group, where x=0 to 20 and y=1 to 42; Including (but not limited to):

[0040] Formula 5 [ka]

[0041] Formula 5 is the general formula [(R2N)2C=C(NR2)2] as shown above. + Formula 6 shows the structure of some example guanidinium cations that can serve as the cation "C" in perovskite materials.

[0042] formula 6 [ka] [ka]

[0043] In certain embodiments, C is an imidazolium cation having the general formula [CRNRCRNRCR] + wherein the R groups may be the same or different groups. Suitable R groups are: hydrogen, methyl, ethyl, propyl, butyl, pentyl groups or isomers thereof; Any alkane, alkene, or alkyne CxHy (where x=1-20, y=1-42, cyclic, branched, or straight chain); alkyl halides, CxHyXz (wherein x=1 to 20, y=0 to 42, z=1 to 42, and X=F, Cl, Br, or I); Any aromatic group (e.g., phenyl, alkylphenyl, alkoxyphenyl, pyridine, naphthalene); cyclic complexes in which at least one nitrogen is contained within the ring (e.g., 2-hexahydropyrimidin-2-ylidenehexahydropyrimidine, octahydropyrazino[2,3-b]pyrazine, pyrazino[2,3-b]pyrazine, quinoxalino[2,3-b]quinoxaline); Any sulfur-containing group (e.g., sulfoxide, thiol, alkyl sulfide); Any nitrogen-containing group (nitroxide, amine); Any phosphorous-containing group (phosphate); 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 alpha, beta, gamma, and larger derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valerate); Any silicon-containing group (e.g., siloxane); and Any alkoxy or -OCxHy group, where x=0 to 20 and y=1 to 42; Including (but not limited to):

[0044] Formula 7 [ka]

[0045] In some embodiments, X can include one or more halides. In certain embodiments, X can alternatively or additionally include a Group 16 anion. In certain embodiments, the Group 16 anion can be sulfide or selenide. In certain embodiments, X can alternatively or additionally include one or more pseudohalides (e.g., cyanide, cyanate, isocyanate, fulminate, thiocyanate, isothiocyanate, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrose, dicyanamide, and tricyanomethanide).

[0046] In one embodiment, the perovskite material can have an empirical formula of CMX3, where C includes one or more of the aforementioned cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds; M includes one or more metals (examples include Fe, Co, Ni, Cu, Ag, Au, Sb, Sn, Pb, Bi, Ga, Ge, Ti, Tl, and Zn); and X includes one or more of the aforementioned anions.

[0047] In one embodiment, the perovskite material can have an empirical formula of C3M2X9, where C includes one or more of the aforementioned cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds; M includes one or more metals (examples include Fe, Co, Ni, Cu, Ag, Au, Sb, Sn, Pb, Bi, Ga, Ge, Ti, Tl, and Zn); and X includes one or more of the aforementioned anions.

[0048] In one embodiment, the perovskite material can have an empirical formula of CM2X7, where C includes one or more of the aforementioned cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds; M includes one or more metals (examples include Fe, Co, Ni, Cu, Ag, Au, Sb, Sn, Pb, Bi, Ga, Ge, Ti, Tl, and Zn); and X includes one or more of the aforementioned anions.

[0049] In one embodiment, the perovskite material can have an empirical formula of C2MX4, where C includes one or more of the aforementioned cations, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds; M includes one or more metals (examples include Fe, Co, Ni, Cu, Ag, Au, Sb, Sn, Pb, Bi, Ga, Ge, Ti, Tl, and Zn); and X includes one or more of the aforementioned anions.

[0050] Perovskite materials may also include mixed ion formulations, where C, M, or X may be two or more species, such as Cs 0.1 FA 0.9 PbI3;FAPb0.5 Sn 0.5 I3;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 Examples of perovskite materials according to various embodiments include CsSnI (discussed earlier herein) and Cs x Sn y I z (x, y, and z vary according to the preceding discussion.) Other examples include compounds of the general formula CsSnX3, where X is I3, I 2.95 F 0.05 ;I2Cl;ICl2;and Cl3; In other embodiments, X can include one or more of I, Cl, F, and Br in an amount such that the total ratio of X compared to Cs and Sn results in a general stoichiometry of CsSnX3. In some embodiments, the combined stoichiometry of the elements that make up X is Cs x Sn y I z Further examples include the general formula RNH3PbX3, where R is C n H 2n+1 where n ranges from 0 to 10, and X can include any one or more of F, Cl, Br, and I in an amount such that the combined ratio of X compared to the cation RNH3 and the metallic Pb results in the general stoichiometry of RNH3PbX3. Additionally, some specific examples of R include H, alkyl chains (e.g., CH3, CH3CH2, CH3CH2CH2, etc.), and amino acids including alpha, beta, gamma, and larger derivatives (e.g., glycine, cysteine, proline, glutamic acid, arginine, serine, histidine, 5-ammonium valerate).

[0051] Device design using composite perovskite materials In some embodiments, the present disclosure may provide hybrid designs for PV and other similar devices (e.g., batteries, hybrid PV batteries, FETs, LEDs, etc.) that include one or more perovskite materials. For example, one or more perovskite materials may serve as either or both of the first and second active materials (e.g., active materials 2810 and 2815 in FIG. 5 ) in some embodiments. More generally, some embodiments of the present disclosure provide PV or other devices having an active layer that includes one or more perovskite materials. In such embodiments, perovskite materials (i.e., materials that include any one or more perovskite material(s)) may be utilized in active layers of various structures. Furthermore, perovskite materials may perform the function(s) of any one or more components of the active layer (e.g., charge transport material, mesoporous material, photoactive material, and / or interfacial material, each of which is discussed in more detail below). In some embodiments, the same perovskite material can perform multiple such functions, while in other embodiments, a plurality of perovskite materials may be included in a device, with each perovskite material performing one or more such functions. In certain embodiments, regardless of what role the perovskite material may play, it may be prepared and / or exist within the device in various states. For example, in some embodiments, it may be substantially solid. In other embodiments, it may be a solution (e.g., the perovskite material may be dissolved in a liquid and exist in individual ionic subspecies within the liquid), or it may be a suspension (e.g., perovskite material particles). The solution or suspension may be coated or otherwise deposited within the device (e.g., onto another component of the device, such as a mesoporous, interfacial, charge transport, photoactive, or other layer, and / or onto an electrode).The perovskite material in some embodiments may be formed in situ on the surface of another component of the device (e.g., by deposition as a thin film solid), although any other suitable means of forming a solid or liquid layer comprising the perovskite material may be utilized.

[0052] Generally, a perovskite material device comprises a first electrode, a second electrode, and an active layer comprising a perovskite material, the active layer being at least partially disposed between the first electrode and the second electrode. In some embodiments, the first electrode may be one of an anode and a cathode, and the second electrode may be the other of the anode and the cathode. The active layer according to certain embodiments comprises: charge transport materials; liquid electrolytes; mesoporous materials; photoactive materials (e.g., dyes, silicon, cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, gallium arsenide, germanium indium phosphide, semiconducting polymers, other photoactive materials); and interface materials; Any one or more of the active layer components may include one or more perovskite materials. In some embodiments, some or all of the active layer components may be disposed in whole or in part within sublayers. For example, the active layer may include: an interfacial layer comprising an interfacial material; a mesoporous layer comprising a mesoporous material; and a charge transport layer comprising a charge transport material; In some embodiments, a photoactive material, such as a dye, may be coated or otherwise disposed on any one or more of these layers. In certain embodiments, any one or more of the layers may be coated with a liquid electrolyte. Additionally, the interfacial layer may include: According to some embodiments, between any two or more other layers of the active layer, and / or between one layer and one coating (e.g., between a dye and a mesoporous layer), and / or Between two coatings (e.g., between a liquid electrolyte and a dye), and / or Between the active layer components and the electrodes, References herein to layers can include either final arrangement (e.g., substantially separate portions of each material separately definable within a device), and / or references to a single layer can refer to the arrangement during construction of a device, notwithstanding the possibility of subsequent intermixing of the material(s) in each layer. In some embodiments, layers can be discrete and include substantially contiguous materials (e.g., layers can be as stylistically shown in FIG. 1). In other embodiments, layers can be substantially intermixed (e.g., as in BHJ, hybrid, and some DSSC cells). An example is shown by the first and second active materials 2618 and 2620 in photoactive layer 2616 in FIG. 4. In some embodiments, a device can include a mixture of these two types of layers, as also shown by the device in FIG. 4. The device of Figure 4 includes discrete contiguous layers 2627, 2626, and 2622 in addition to photoactive layer 2616, which includes intermixed layers of first and second active materials 2618 and 2620. In any event, in certain embodiments, any two or more layers of either type may be disposed adjacent to one another (and / or intermixed with one another) in a manner to achieve a high contact surface area. In certain embodiments, a layer including a perovskite material may be disposed adjacent to one or more other layers to achieve a high contact surface area (e.g., if the perovskite material exhibits low charge mobility). In other embodiments, a high contact surface area may not be necessary (e.g., if the perovskite material exhibits high charge mobility).

[0053] Perovskite material devices according to some embodiments may optionally include one or more substrates. In some embodiments, either or both of the first electrode and the second electrode may be coated or otherwise disposed on the substrate such that the electrode is disposed substantially between the substrate and the active layer. The materials of the device composition (e.g., substrate, electrodes, active layer, and / or active layer components) may be either wholly or partially rigid or flexible in various embodiments. In some embodiments, the electrodes may function as the substrate, thereby negating the need for a separate substrate.

[0054] Further, perovskite material devices according to certain embodiments may optionally include a light-harvesting material (e.g. in a light-harvesting layer such as light-harvesting layer 1601 as depicted in the exemplary PV shown in Figure 2). In addition, the perovskite material device may include any one or more additives, such as any one or more of the additives discussed above with respect to some embodiments of the present disclosure.

[0055] Some of the various materials that may be included in a perovskite material device arrangement will be described in part with reference to FIG. 7 , which is a stylized diagram of a perovskite material device 3900 according to some embodiments. While various components of the device 3900 are shown as discrete layers comprising continuous materials, it should be understood that FIG. 7 is a stylized diagram. Accordingly, embodiments according thereto may include such discrete layers and / or substantially intermixed, non-continuous layers, consistent with the use of “layers” discussed earlier herein. The device 3900 includes first and second substrates 3901 and 3913. A first electrode 3902 is disposed on the inner surface of the first substrate 3901, and a second electrode 3912 is disposed on the inner surface of the second substrate 3913. An active layer 3950 is sandwiched between the two electrodes 3902 and 3912. Active layer 3950 includes mesoporous layer 3904; first and second photoactive materials 3906 and 3908; charge transport layer 3910; and several interfacial layers. Figure 7 further illustrates an exemplary device 3900 according to an embodiment, where sublayers of active layer 3950 are separated by interfacial layers, and where an interfacial layer is disposed on each electrode 3902 and 3912. In particular, second interfacial layer 3905, third interfacial layer 3907, and fourth interfacial layer 3909 are disposed between mesoporous layer 3904, first photoactive material 3906, second photoactive material 3908, and third charge transport layer 3910, respectively. First interfacial layer 3903 and fifth interfacial layer 3911 are disposed between mesoporous layer 3904, first photoactive material 3906, second photoactive material 3908, and third charge transport layer 3910, respectively. (i) between the first electrode 3902 and the mesoporous layer 3904; and (ii) between the charge transport layer 3910 and the second electrode 3912; Thus, the structure of the exemplary device depicted in FIG. Substrate-electrode-active layer-electrode-substrate The structure of the active layer 3950 can be characterized as: Interfacial layer - mesoporous layer - interfacial layer - photoactive material - interfacial layer - photoactive material - interfacial layer - charge transport layer - interfacial layer As previously mentioned, in some embodiments, no interfacial layer need be present, or one or more interfacial layers may be included only between certain, but not all, components of the active layer and / or device.

[0056] The substrates, e.g., either or both of the first substrate 3901 and the second substrate 3913, may be flexible or rigid. If two substrates are included, at least one must be transparent or translucent to electromagnetic (EM) radiation (e.g., UV, visible, or IR radiation). If one substrate is included, it may be transparent or translucent as well, although portions of the device need not necessarily be so, as long as they allow EM radiation to contact the active layer 3950. Suitable substrate materials include: glass; sapphire; magnesium oxide (MgO); mica; polymers (e.g., PET, PEG, polypropylene, polyethylene, etc.); ceramics; fabrics (e.g., cotton, silk, wool); wood; drywall; metal; and combinations thereof; Includes one or more of the following.

[0057] As previously mentioned, an electrode (e.g., one of electrodes 3902 and 3912 in FIG. 7) may be either an anode or a cathode. In some embodiments, one electrode can function as a cathode and the other can function as an anode. Either or both of electrodes 3902 and 3912 can be coupled to leads, cables, wires, or other means that allow charge transport to and / or from device 3900. The electrodes can comprise any conductive material, and at least one electrode must be transparent or semi-transparent to EM radiation and / or positioned to allow EM radiation to contact at least a portion of active layer 3950. Suitable electrode materials include: 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); calcium (Ca); magnesium (Mg); titanium (Ti); steel; carbon (and its allotropes); and combinations thereof; It may contain one or more of the following:

[0058] Mesoporous materials (e.g., materials included in mesoporous layer 3904 of FIG. 7) can include any pore-containing material. In some embodiments, the pores can have diameters ranging from about 1 to about 100 nm, and in other embodiments, the pore diameters can range from about 2 to about 50 nm. Suitable mesoporous materials include: Any interfacial material and / or mesoporous material discussed elsewhere herein; aluminum (Al); bismuth (Bi); indium (In); molybdenum (Mo); niobium (Nb); nickel (Ni); silicon (Si); titanium (Ti); vanadium (V); zinc (Zn); zirconium (Zr); oxides of any one or more of the above metals; sulfides of any one or more of the above metals (e.g., alumina, ceria, titania, zinc oxide, zircona, etc.); nitrides of any one or more of the above metals; and combinations thereof; Includes one or more of the following.

[0059] The photoactive material (e.g., first photoactive material 3906 or second photoactive material 3908 in FIG. 7 ) can include any photoactive compound, such as any one or more of silicon (in some instances, single-crystal silicon), cadmium telluride, cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, gallium arsenide, germanium indium phosphide, one or more semiconducting polymers, and combinations thereof. In certain embodiments, the photoactive material can alternatively or additionally include a dye (e.g., N719, N3, other ruthenium-based dyes). In some embodiments, the dye (of any composition) can be coated on another layer (e.g., a mesoporous layer and / or an interfacial layer). In some embodiments, the photoactive material can include one or more perovskite materials. The perovskite-containing photoactive material may be in solid form, or in some embodiments, may take the form of a dye-containing suspension or solution containing the perovskite material. Such a solution or suspension can be coated onto other device components in a similar manner to other dyes. In some embodiments, the solid perovskite-containing material may be deposited by any suitable means (e.g., vapor deposition, solution deposition, direct deposition of solid materials, etc.). Devices according to various embodiments may include one, two, three, or more photoactive compounds (e.g., one, two, three, or more perovskite materials, dyes, or combinations thereof). In certain embodiments including multiple dyes or other photoactive materials, each of the two or more dyes or other photoactive materials may be separated by one or more interfacial layers. In some embodiments, multiple dyes and / or photoactive compounds may be at least partially intermixed.

[0060] The charge transport material (e.g., the charge transport material of charge transport layer 3910 in FIG. 7) can include a solid charge transport material (i.e., colloquially labeled solid-state electrolyte), or can include a liquid electrolyte and / or an ionic liquid. Any of a liquid electrolyte, an ionic liquid, and a solid-state charge transport material can 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 PV devices according to some embodiments, the charge transport material can transport charge carriers to an electrode. Charge carriers can include holes (the transport of which could make the charge transport material as appropriately labeled a "hole transport material") and electrons. Depending on the location of the charge transport material relative to either the cathode or anode in a PV or other device, holes may be transported toward the anode, and electrons may be transported toward the cathode. Suitable examples of charge transport materials according to some embodiments include: Perovskite Materials; I - / I3 - Co complexes; polythiophenes (e.g., poly(3-hexylthiophene) and its derivatives, or P3HT); carbazole-based copolymers, such as polyheptadecanylcarbazole dithienylbenzothiadiazole and its derivatives (e.g., PCDTBT); other copolymers, such as polycyclopentadithiophene-benzothiadiazole and its derivatives (e.g., PCPDTBT); poly(triarylamine) compounds and their derivatives (e.g., PTAA); Spiro-OMeTAD; fullerenes and / or fullerene derivatives (e.g., C60, PCBM); and combinations thereof; In certain embodiments, the charge transport material can include any material, solid or liquid, that can collect (electrons or holes) and / or transport charge carriers. Thus, the charge transport material of some embodiments can be an n-type or p-type active material and / or a semiconducting material. The charge transport material can be disposed adjacent to one of the electrodes of the device. In some embodiments, it can be disposed adjacent to an electrode, while in other embodiments, an interfacial layer can be disposed between the charge transport material and the electrode (e.g., fifth interfacial layer 3911 as shown in FIG. 7). In certain embodiments, the type of charge transport material can be selected based on the electrode it is adjacent to. For example, if the charge transport material collects and / or transports holes, it can be adjacent to the anode to transport holes to the anode. However, instead, the charge transport material can be disposed adjacent to the cathode and selected or configured to transport electrons to the cathode.

[0061] As previously mentioned, devices according to various embodiments can optionally include an interfacial layer between any two other layers and / or materials, although devices according to some embodiments need not include any interfacial layers. Thus, for example, a perovskite material device can include zero, one, two, three, four, five, or more interfacial layers (e.g., the exemplary device of FIG. 7 includes five interfacial layers 3903, 3905, 3987, 3909, and 3911). The interfacial layer can include a thin-film-coated interfacial layer according to embodiments previously discussed herein (e.g., including alumina and / or other metal oxide particles, and / or titania / metal oxide bilayers, and / or other compounds, in accordance with the thin-film-coated interfacial layers discussed elsewhere herein). An interfacial layer according to some embodiments can include any suitable material suitable for facilitating charge transport and / or collection between two layers or materials; it may also help prevent or reduce the likelihood of charge recombination when charge is transferred away from one of the materials adjacent to the interfacial layer. Suitable interface materials are: Any mesoporous and / or interfacial materials discussed elsewhere herein; Al; Bi; In; Mo; Ni; platinum (Pt); Si; Ti; V; Nb; Zn; Zr; oxides of any of the foregoing metals (e.g., alumina, silica, titania); sulfides of any of the foregoing metals; nitrides of any of the foregoing metals; functionalized or non-functionalized alkylsilyl groups; graphite; graphene; fullerenes; carbon nanotubes; and combinations thereof (in some embodiments, including bilayers of combined materials); In some embodiments, the interfacial layer may comprise a perovskite material.

[0062] The device according to the stylized representation of FIG. 7 may, in some embodiments, be a PV such as a DSSC, BHJ, or hybrid solar cell. In some embodiments, the device according to FIG. 7 may constitute a parallel or series multicell PV, a battery, a hybrid PV battery, a FET, an LED, and / or any other device discussed herein. For example, the BHJ of some embodiments may include two electrodes corresponding to electrodes 3902 and 3912 and an active layer including at least two materials at a heterojunction interface (e.g., any two of the materials and / or layers of active layer 3950). In certain embodiments, other devices (e.g., hybrid PV batteries, parallel or series multicell PVs, etc.) may include an active layer including a perovskite material corresponding to active layer 3950 of FIG. 7. In short, the stylized nature of the depiction of the exemplary device in FIG. 7 in no way limits the permissible structure or architecture of various embodiment devices according to FIG. 7.

[0063] Further, more specific, exemplary embodiments of perovskite devices will be discussed with respect to further stylized depictions of exemplary devices. The stylized nature of these depictions, FIGS. 8-9, is likewise not intended to limit the types of devices that may, in some embodiments, be configured according to any one or more of FIGS. 8-9. That is, the architectures shown in FIGS. 8-9 may be adapted to provide BHJs, batteries, FETs, hybrid PV batteries, serial multi-cell PVs, parallel multi-cell PVs, and other similar devices according to other embodiments of the present disclosure, according to any suitable means, including both those explicitly discussed elsewhere herein and other suitable means that will be apparent to those of ordinary skill in the art having the benefit of this disclosure.

[0064] 8 depicts an exemplary device 4100 according to various embodiments. Device 4100 shows an embodiment including a first glass substrate 4101 and a second glass substrate 4109. Each glass substrate has an FTO electrode disposed on its inner surface (first electrode 4102 and second electrode 4108, respectively), and each electrode has an interfacial layer deposited on its inner surface. That is, a TiO first interfacial layer 4103 is deposited on the first electrode 4102, and a Pt second interfacial layer 4107 is deposited on the second electrode 4108. Between the two interfacial layers: mesoporous layer 4104 (comprising TiO2); photoactive material 4105 (comprising the perovskite material MAPbI3); and charge transport layer 4106 (here comprising CsSnI3); is sandwiched in between.

[0065] 9 depicts an exemplary device 4300 omitting the mesoporous layer. Device 4300 includes a perovskite material photoactive compound 4304 (comprising MAPbI3) sandwiched between a first interfacial layer 4303 and a second interfacial layer 4305 (comprising titania and alumina, respectively). Titania interfacial layer 4303 is coated on an FTO first electrode 4302, which in turn is disposed on the inner surface of a glass substrate 4301. Spiro-OMeTAD charge transport layer 4306 is coated on the alumina interfacial layer 4305 and disposed on the inner surface of a gold second electrode 4307.

[0066] Various other embodiments are possible, as would be apparent to one of ordinary skill in the art given the benefit of this disclosure. For example, devices having multiple photoactive layers (as exemplified by photoactive layers 3906 and 3908 of the exemplary device in FIG. 7 ). In some embodiments, as discussed above, each photoactive layer may be separated by an interfacial layer (as illustrated by third interfacial layer 3907 in FIG. 7 ). Additionally, mesoporous layers may be disposed on electrodes. For example, as shown in FIG. 7 , mesoporous layer 3904 is disposed on first electrode 3902. While FIG. 7 depicts an intervening interfacial layer 3903 between the two, in some embodiments, the mesoporous layer can be disposed directly on the electrode.

[0067] Additional perovskite material device examples Other exemplary perovskite material device architectures will be apparent to those skilled in the art having the benefit of this disclosure. Examples include the following architectures: (1) Liquid electrolyte-perovskite material-mesoporous layer; (2) Perovskite material-dye-mesoporous layer; (3) first perovskite material-second perovskite material-mesoporous layer; (4) a first perovskite material—a second perovskite material; (5) first perovskite material-dye-second perovskite material; (6) Solid-state charge transport materials - perovskite materials; (7) Solid-state charge transport material-dye-perovskite material-mesoporous layer; (8) Solid-state charge transport material-perovskite material-dye-mesoporous layer; (9) solid-state charge transport material-dye-perovskite material-mesoporous layer; and (10) Solid-state charge transport material-perovskite material-dye-mesoporous layer; Examples of exemplary architectures include, but are not limited to, devices comprising an active layer having any of the following: The individual components of each exemplary architecture (e.g., mesoporous layer, charge transport material, etc.) can be subject to the discussion above for each component. Further, each exemplary architecture is discussed in more detail below.

[0068] As some specific examples of the active layer described above, in some embodiments, the active layer can include a liquid electrolyte, a perovskite material, and a mesoporous layer. The active layer of some of these embodiments can have substantially the following architecture: liquid electrolyte-perovskite material-mesoporous layer. Any liquid electrolyte may be suitable, and any mesoporous layer (e.g., TiO) may be suitable. In some embodiments, the perovskite material may be deposited on the mesoporous layer and then coated with the liquid electrolyte. The perovskite material in some such embodiments may act, at least in part, as a dye (and thus may be photoactive).

[0069] In other embodiments, the active layer can include a perovskite material, a dye, and a mesoporous layer. Certain active layers in these embodiments can have essentially the following architecture: perovskite material-dye-mesoporous layer. The dye can be coated on the mesoporous layer, and the perovskite material can be disposed on the dye-coated mesoporous layer. In some of these embodiments, the perovskite material can function as a hole transport material.

[0070] In still other exemplary embodiments, the active layer may comprise a first perovskite material, a second perovskite material, and a mesoporous layer. The active layer in some of these embodiments may have substantially the following architecture: first perovskite material-second perovskite material-mesoporous layer. The first perovskite material and the second perovskite material may each comprise the same perovskite material(s), or they may comprise different perovskite materials. Either the first perovskite material and the second perovskite material may be photoactive (e.g., the first perovskite material and / or the second perovskite material in such embodiments may function, at least in part, as a dye).

[0071] In certain exemplary embodiments, the active layer can comprise a first perovskite material and a second perovskite material. The active layer in some of these embodiments can have substantially the following architecture: first perovskite material - second perovskite material. The first perovskite material and the second perovskite material can each comprise the same perovskite material(s), or they can comprise different perovskite materials. Either the first perovskite material or the second perovskite material can be photoactive (e.g., the first perovskite material and / or the second perovskite material in such embodiments can function at least in part as a dye). Additionally, either the first perovskite material or the second perovskite material can function as a hole transport material. In some embodiments, one of the first and second perovskite materials functions as an electron transport material, and the other of the first and second perovskite materials functions as a dye. In some embodiments, the first and second perovskite materials may be arranged in the active layer in a manner that achieves a high interfacial area between the first and second perovskite materials, for example in the arrangement shown for first active material 2810 and second active material 2815, respectively, in Figure 5 (or similarly shown by p-type material 2618 and n-type material 2629 in Figure 4).

[0072] In further exemplary embodiments, the active layer can include a first perovskite material, a dye, and a second perovskite material. The active layer in some of these embodiments can have substantially the following architecture: first perovskite material-dye-second perovskite material. Either the first or second perovskite material can function as a charge transport material, and the other of the first or second perovskite material can function as a dye. In some embodiments, both the first and second perovskite materials can at least partially overlap and serve similar and / or identical functions (e.g., both can function as dyes and / or both can function as hole transport materials).

[0073] In some other exemplary embodiments, the active layer can include a solid-state charge transport material and a perovskite material. The active layer of some of these embodiments can have substantially the following architecture: solid-state charge transport material-perovskite material. For example, the perovskite material and solid-state charge transport material can be arranged in the active layer in a manner that achieves a high interfacial area, such as in the arrangement shown for first active material 2810 and second active material 2815, respectively, in FIG. 5 (or similarly shown by p-type material 2618 and n-type material 2629 in FIG. 4).

[0074] In other exemplary embodiments, the active layer can include a solid-state charge transport material, a dye, a perovskite material, and a mesoporous layer. The active layer of some of these embodiments can have substantially the following architecture: solid-state charge transport material-dye-perovskite material-mesoporous layer. The active layer of certain other of these embodiments can have substantially the following architecture: solid-state charge transport material-perovskite material-dye-mesoporous layer. The perovskite material can, in some embodiments, serve as a second dye. In such embodiments, the perovskite material can broaden the spectral breadth of visible light absorbed by a PV or other device including the active layer of such embodiments. In certain embodiments, the perovskite material can also, or instead, function as an interfacial layer between the dye and the mesoporous layer and / or between the dye and the charge transport material.

[0075] In some exemplary embodiments, the active layer may include a liquid electrolyte, a dye, a perovskite material, and a mesoporous layer. The active layer in some of these embodiments may have substantially the following architecture: solid-state charge transport material-dye-perovskite material-mesoporous layer. The active layer in certain other of these embodiments may have substantially the following architecture: solid-state charge transport material-perovskite material-dye-mesoporous layer. The perovskite material may function as a photoactive material, an interfacial layer, and / or a combination thereof.

[0076] Some embodiments provide a BHJ PV device comprising a perovskite material. For example, the BHJ of some embodiments can include a photoactive layer (e.g., photoactive layer 2404 of FIG. 3 ) and can include one or more perovskite materials. The photoactive layer of such a BHJ can also, or instead, include any one or more of the above-listed exemplary components discussed above with respect to the DSSC active layer. Furthermore, in some embodiments, the BHJ photoactive layer can have an architecture according to any one of the exemplary embodiments of the DSSC active layer discussed above.

[0077] In some embodiments, any PV or other similar device can include an active layer according to any one or more of the compositions and / or architectures described above. As another exemplary embodiment, an active layer including a perovskite material may be included in a multiple photoactive layer PV cell, such as either or both of the first and second photoactive layers 3701 and 3705 of the exemplary cell shown in the stylized diagram of Figure 6. Such multiple photoactive layer PV cells including an active layer with a perovskite material may further be incorporated into a series of electrically coupled multiple photoactive layer PV cells.

[0078] In some embodiments, any of the active layers comprising a perovskite material incorporated into a PV or other device discussed herein further comprises any of a variety of additional materials also discussed herein as suitable for inclusion in the active layer. For example, any active layer comprising a perovskite material can further comprise an interfacial layer according to various embodiments discussed herein (e.g., a thin-film coated interfacial layer, etc.). As a further example, an active layer comprising a perovskite material can further comprise a light harvesting layer, such as light harvesting layer 1601 as depicted in the exemplary PV shown in Figure 2.

[0079] Perovskite material active layer formulation As mentioned above, in some embodiments, the perovskite material can be of the general formula CwMyXz, where: C includes one or more cations (e.g., amines, ammonium, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds); M includes one or more metals (examples include Fe, Co, Ni, Cu, Ag, Au, Tl, In, Sb, Sn, Pb, Bi, Ga, Ge, Ti, and Zn); X includes one or more anions; and w, y, and z represent real numbers between 1 and 20. In some embodiments, the perovskite material in the active layer can be of the formula CMX 3-y X' y (0≧y≧3), wherein C comprises one or more cations (e.g., amines, Group 1 metals, Group 2 metals, and / or other cations or cation-like compounds); M comprises one or more metals (e.g., Fe, Cd, Co, Ni, Cu, Hg, Sn, Pb, Bi, Ge, Ti, Zn, and Zr); and X and X' comprise one or more anions. In one embodiment, the perovskite material is CPbI 3-y Cl y In certain embodiments, the perovskite material may be deposited as an active layer in a PV device using the steps described onto 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.

[0080] First, a lead halide precursor ink is formed. A quantity of lead halide can be collected in a clean, dry vial inside a glove box (i.e., a controlled atmosphere box with glove-containing portholes allows for material manipulation 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 can include a single species of lead halide or a mixture of lead halides in precise ratios. In certain embodiments, the lead halide mixture can include binary, ternary, or quaternary ratios of any of 0.001 to 100 mole percent iodide, bromide, chloride, or fluoride. In one embodiment, the lead halide mixture can include lead(II) chloride and lead(II) iodide in a ratio of approximately 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.

[0081] A solvent can then be added to the vial to dissolve the lead solids 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, dimethylsulfoxide (DMSO), methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the lead solids are dissolved in dry dimethylformamide (DMF). The lead solids can be dissolved at temperatures between about 20°C and about 150°C. In one embodiment, the lead solids are dissolved at about 85°C. The lead solids can be dissolved for as long as necessary to form a solution, which can be up to about 72 hours. The resulting solution forms the base of the lead halide precursor ink. In some embodiments, the lead halide precursor ink may have a lead halide concentration between about 0.001 M and about 10 M. In one embodiment, the lead halide precursor ink has a lead halide concentration of about 1 M. In some embodiments, the lead halide precursor ink may further include an amino acid (e.g., 5-aminovaleric acid, histidine, glycine, lysine), an amino acid hydrohalide (e.g., 5-aminovaleric acid hydrochloride), an IFL surface modifying (SAM) agent (such as those discussed previously herein), or a combination thereof.

[0082] The lead halide precursor ink can then be deposited onto a desired substrate. Suitable substrate layers can include any of the substrate layers previously identified in this disclosure. As discussed above, the lead halide precursor ink can be applied by 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 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 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 onto the substrate in an ambient atmosphere in a humidity range of about 0% relative humidity to about 50% relative humidity. The lead halide precursor ink can then be dried in a substantially water-free atmosphere, i.e., at a relative humidity of less than 20%, to form a thin film.

[0083] 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. In one embodiment, the thin film can be thermally annealed at a temperature of about 50°C for about 10 minutes. The perovskite material active layer can then be completed by a conversion process, in which the precursor film is immersed in or rinsed with a solution containing a solvent or solvent mixture (e.g., DMF, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide, water, etc.) and a salt (e.g., methylammonium iodide, formamidinium iodide, guanidinium iodide, 1,2,2-triaminovinylammonium iodide, 5-aminovaleric acid hydroiodide) 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 in the first line of this paragraph.

[0084] In another embodiment, the perovskite material can include C'CPbX3, 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 other embodiments, C' can be rubidium (Rb). In other embodiments, C' can be sodium (Na). In other embodiments, C' can be potassium (K). In still other embodiments, the perovskite material can include C' v C w Pb y X z where C' is one or more Group 1 metals, and v, w, y, and z represent real numbers between 1 and 20. In certain embodiments, the perovskite material can be deposited as an active layer in a PV device by, for example, drop casting, spin casting, gravure coating, blade coating, reverse gravure coating, slot-die printing, screen printing, or inkjet printing onto a substrate layer using the procedures described below.

[0085] First, a lead halide solution is formed. A quantity of lead halide may be combined in a clean, dry container in a controlled atmosphere 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 include a single lead halide or a mixture of lead halides in precise ratios. In one embodiment, the lead halide may include lead(II) iodide. In certain embodiments, the lead halide mixture may include any binary, ternary, or quaternary ratio of 0.001 to 100 mole percent 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 mole:mol. In other embodiments, the lead halide mixture can include lead(II) chloride and lead(II) iodide in a ratio of about 5:95, about 7.5:92.5, or about 15:85 mole:mol.

[0086] Alternatively, other lead salt precursors may be used in conjunction with or in place of the lead halide salt to form the lead salt solution. Suitable precursor lead salts include lead(II) or lead(IV) in combination with any of the following anions: Nitric acid, nitrous acid, carboxylic acid, acetic acid, formic acid, oxylate, sulfuric acid, sulfurous acid, thiosulfate, phosphoric acid, tetrafluoroboric acid, hexafluorophosphoric acid, tetra(perfluorophenyl)boric acid, hydride, oxide, peroxide, hydroxide, nitride, arsenic acid, arsenous acid, perchloric acid, carbonic acid, bicarbonate, chromic acid, dichromate, iodic acid, bromic acid, chloric acid, chlorous acid, hypochlorous acid, hypobromous acid, cyanide, cyanic acid, isocyanate, fulmic acid, thiocyanic acid, isothiocyanic acid, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosomethanide, dicyanamide, tricyanomethanide, amide, and permanganic acid.

[0087] The lead salt solution may further comprise, as salts of the aforementioned anions, lead(II) or lead(IV) salts in molar ratios of 0 to 100% relative to the following metal ions: Fe, Cd, Co, Ni, Cu, Hg, Sn, Pb, Bi, Ge, Ti, Zn, and Zr.

[0088] A solvent can then be added to the container to dissolve the lead halide solids and form a lead halide solution. Suitable solvents include, but are not limited to, dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethylsulfoxide (DMSO), methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the lead solids are dissolved in dry dimethylformamide (DMF). The lead halide solids dissolve at temperatures between about 20°C and about 150°C. In one embodiment, the lead halide solids dissolve at about 85°C. The lead halide solids can be dissolved for as long as necessary to form a solution, which can occur over a period of up to about 72 hours. The resulting solution forms the base of the lead halide precursor ink. In some embodiments, the lead halide precursor ink may have a lead halide concentration of between about 0.001 M and about 10 M. In one embodiment, the lead halide precursor ink has a lead halide concentration of about 1 M. In some embodiments, the lead 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 (such as those previously described herein), or a combination thereof.

[0089] A Group 1 metal halide solution is then formed. A quantity of Group 1 metal halide may be combined in a clean, dry container in a controlled atmosphere environment. 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 chloride, sodium fluoride, potassium iodide, potassium bromide, potassium chloride, and potassium fluoride. The Group 1 metal halide may comprise a single Group 1 metal halide or may comprise a mixture of Group 1 metal halides in precise 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 include potassium iodide.

[0090] Alternatively, other Group 1 metal salt precursors can be used in combination with or in place of the Group 1 metal halide salt to form the Group 1 metal salt solution. Suitable precursor Group 1 metal salts can include any combination of a Group 1 metal and the following anions: : Nitrate, nitrous acid, carboxylic acid, acetic acid, formic acid, oxylate, sulfate, sulfurous acid, thiosulfate, phosphoric acid, tetrafluoroboric acid, hexafluorophosphate, tetra(perfluorophenyl)boric acid, hydride, oxide, peroxide, hydroxide, nitride, arsenic acid, arsenous acid, perchloric acid, carbonate, bicarbonate, chromic acid, dichromate, iodic acid, bromic acid, chloric acid, chlorous acid, hypochlorous acid, hypobromous acid, cyanide, cyanic acid, isocyanate, fulmic acid, thiocyanic acid, isothiocyanic acid, azide, tetracarbonylcobaltate, carbamoyldicyanomethanide, dicyanonitrosemethanide, dicyanamide, tricyanomethanide, amide, and permanganic acid.

[0091] A solvent can then be added to the vessel to dissolve the Group 1 metal halide solids and 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), methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof. In one embodiment, the lead solids are dissolved in dry dimethyl sulfoxide (DMSO). The Group 1 metal halide solids dissolve at a temperature of about 20°C to about 150°C. In one embodiment, the Group 1 metal halide solids are dissolved at room temperature (i.e., about 25°C). The Group 1 metal halide solids are allowed to dissolve for 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 Group 1 metal halide solution. In some embodiments, the Group 1 metal halide solution can have a Group 1 metal halide concentration of between about 0.001 M and about 10 M. In one embodiment, the Group 1 metal halide solution has a Group 1 metal halide concentration of about 1 M. In some 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 (such as those previously described herein), or a combination thereof.

[0092] The lead halide solution and the Group 1 metal halide solution are then mixed to form a thin film precursor ink. The lead halide solution and the Group 1 metal halide solution may be mixed in a ratio such that the resulting thin film precursor ink has a molar concentration of the Group 1 metal halide that is between 0% and 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 Group 1 metal halide that is 25% of the molar concentration of lead halide. In some embodiments, the lead halide solution and the Group 1 metal halide solution may be stirred or agitated during or after mixing.

[0093] The thin film precursor ink can then be deposited onto a desired substrate. Suitable substrate layers can include any of the substrate layers previously identified in this disclosure. As noted above, the thin film precursor ink can be deposited via a variety of 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 onto a 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 onto a substrate at about 3000 rpm for about 30 seconds. The thin film precursor ink can be deposited onto a substrate in an ambient atmosphere within a humidity range of about 0% relative humidity to about 50% relative humidity. The thin film precursor ink can then be dried in a substantially water-free atmosphere, i.e., at a relative humidity of less than 20%, to form a thin film.

[0094] The thin film can then be thermally annealed at a temperature of about 20°C to about 300°C for 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. The active layer of the perovskite material can then be completed by a conversion process in which the precursor film is immersed or rinsed in a solvent or salt solution containing a mixture of a solvent (e.g., DMF, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide, water) and a salt (e.g., methylammonium iodide, formamidinium iodide, guanidinium iodide, 1,2,2-triaminovinylammonium iodide, 5-aminovaleric acid hydroiodide) at a concentration between 0.001M and 10M. In certain embodiments, the perovskite material thin film can also be thermally post-annealed in the same manner as in the first line of this paragraph.

[0095] In some embodiments, the salt solution can be prepared by massing salts in a clean, dry container in a controlled atmosphere environment. 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 of the organic cations described above in the section titled "Perovskite Materials." The salt can include a single salt or a mixture of salts in the correct ratios. In one embodiment, the salt can include methylammonium iodide. In another embodiment, the salt can include formamidinium iodide. A solvent can then be added to the container to dissolve the salt solids and form a salt solution. Suitable solvents include, but are not limited to, DMF, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide, water, and combinations thereof. In one embodiment, the formamidinium iodide salt solid is dissolved in isopropanol. The salt solid may be dissolved at a temperature of about 20°C to about 150°C. In one embodiment, the salt solid is dissolved at room temperature (i.e., about 25°C). The salt solid is allowed to dissolve for as long as necessary to form a solution, which may occur over a period of up to about 72 hours. The resulting solution forms a salt solution. In some embodiments, the salt solution may have a salt concentration between about 0.001M and about 10M. In one embodiment, the salt solution has a salt concentration of about 1M.

[0096] For example, the above process can be used with lead(II) iodide solution, cesium iodide solution, and methylammonium iodide (MA) salt solution to produce Cs i A perovskite material with the formula MAPbI3 is obtained, where i is a number between 0 and 1. As another example, lead(II) iodide solution, rubidium iodide solution, and formamidinium iodide (FA) salt solution can be used to obtain Rb iA perovskite material with the formula FAPbI3 is obtained, where i is a number between 0 and 1. As another example, lead(II) iodide solution, cesium iodide solution, and formamidinium iodide (FA) salt solution can be used to obtain Cs i Perovskite materials with the formula FAPbI3, where i is a number between 0 and 1, can be obtained. As another example, lead(II) iodide solution, potassium iodide solution, and formamidinium iodide (FA) salt solution can be used to obtain K i Perovskite materials with the formula FAPbI3, where i is a number between 0 and 1, may be obtained. As another example, the use of lead(II) iodide solution, sodium iodide solution, and formamidinium (FA) iodide salt solution results in the formation of Na i Perovskite materials with the formula FAPbI3, where i is a number between 0 and 1, can be obtained. As another example, mixed solutions of lead(II) iodide and lead(II) chloride, cesium iodide solutions, and formamidinium (FA) iodide salt solutions can be used to obtain Cs i FAPbI 3-y CL y A perovskite material having the formula: where i is a number between 0 and 1 and y is a number between 0 and 3 may be obtained.

[0097] Thus, the present invention is well adapted to achieve the ends and advantages set forth above, as well as the benefits inherent therein. The specific embodiments described above are illustrative only, as modifications and practices may be implemented in different but equivalent manners, as will be apparent to those skilled in the art having the benefit of the teachings of this invention. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as set forth in the following claims. It is therefore evident that the specific exemplary embodiments disclosed above may be altered or modified, and all such variations are deemed to be within the scope and spirit of the present invention. In particular, any range of values ​​disclosed herein ("about a to about b" or, equivalently, "approximately a to approximately b" or, equivalently, "approximately a to b") should be understood to mean the power set (set of all subsets) of the respective range values, and to represent all ranges encompassed by the broader range of values. Furthermore, terms in the claims are to have their plain and ordinary meaning unless expressly and unambiguously defined otherwise by the patentee.

Claims

1. Steps below: Preparing a thin film precursor ink, comprising: contacting a lead halide with a first solvent to dissolve the lead halide and form a lead halide solution; contacting a Group 1 metal halide, including cesium iodide, cesium chloride, rubidium iodide, or potassium iodide, with a second solvent to dissolve the Group 1 metal halide and form a Group 1 metal halide solution, wherein the second solvent is different from the first solvent; and contacting the lead halide solution with the Group 1 metal halide solution to form the thin film precursor ink; and depositing the thin film precursor ink onto a substrate; drying the thin film precursor ink to form a thin film; annealing the thin film; immersing the thin film in a salt solution comprising a third solvent and a salt selected from the group consisting of methylammonium halide, formamidinium halide, guanidinium halide, ethenetetramine halide, imidazolium halide, 1,2,2-triaminovinylammonium halide, and 5-aminovaleric acid hydrogen halide; A method comprising:

2. The method of claim 1 , wherein the lead halide comprises lead (II) iodide.

3. 2. The method of claim 1, wherein the first solvent and the second solvent are selected from the group consisting of dry N-cyclohexyl-2-pyrrolidone, alkyl-2-pyrrolidone, dimethylformamide (DMF), dialkylformamide, dimethylsulfoxide (DMSO), methanol, ethanol, propanol, butanol, tetrahydrofuran, formamide, tert-butylpyridine, pyridine, alkylpyridine, pyrrolidine, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, and combinations thereof.

4. 10. The method of claim 1, wherein the first solvent comprises dry dimethylformamide (DMF).

5. The method of claim 1 , wherein the second solvent comprises dimethyl sulfoxide (DMSO).

6. 10. The method of claim 1, wherein the third solvent is selected from the group consisting of dimethylformamide, isopropanol, methanol, ethanol, butanol, chloroform, chlorobenzene, dimethyl sulfoxide, water, and combinations thereof.

7. 10. The method of claim 1, wherein the thin film precursor ink has a molar concentration of the Group 1 metal halide that is between 1% and 25% of the molar concentration of the lead halide.

8. 10. The method of claim 1, wherein annealing the thin film occurs at a temperature between about 40°C and about 60°C for about 5 minutes to about 30 minutes.

9. 10. The method of claim 1, wherein the salt comprises formamidinium iodide.

10. The method of claim 1 , wherein the salt comprises methylammonium iodide.

11. The method of claim 1 , wherein rinsing the thin film comprises at least partially immersing the thin film in the salt solution.

12. Steps below: Preparing a thin film precursor ink, comprising: contacting a Group 1 metal halide, including cesium iodide, cesium chloride, rubidium iodide, or potassium iodide, and a lead halide with a first solvent to form a thin film precursor solution; depositing the thin film precursor ink onto a substrate; drying the thin film precursor ink to form a thin film; annealing the thin film; immersing the thin film in a salt solution comprising a second solvent and a salt selected from the group consisting of methylammonium halide, formamidinium halide, guanidinium halide, ethenetetramine halide, imidazolium halide, 1,2,2-triaminovinylammonium halide, and 5-aminovaleric acid hydrogen halide; and The method of claim 1, wherein the thin film precursor ink has a molar concentration of the Group 1 metal halide that is between 1% and 25% of the molar concentration of the lead halide.

13. The method of claim 11 , further comprising contacting a third solvent with the first solvent or the thin film precursor solution.

14. 12. The method of claim 11, wherein the lead halide comprises lead (II) iodide and the Group 1 metal halide comprises cesium iodide.

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