Apparatus and method for forming metal-halide perovskite films

Abstract

Forming a perovskite film on a substrate includes atomizing a perovskite precursor composition to produce perovskite precursor droplets. The method includes forming a perovskite precursor droplet on a substrate, accelerating the perovskite precursor droplet toward the substrate at sub-atmospheric pressure, collecting the perovskite precursor droplet on the substrate to produce a perovskite precursor layer on the substrate, and forming a perovskite film on the substrate. The perovskite precursor composition includes one or more perovskite precursors. The perovskite film has a crystal structure ABX3 wherein A represents one or more organic cations, one or more inorganic cations, or both, B represents one or more metal cations, and X represents one or more halogen anions. The coated substrate includes a substrate and a perovskite precursor composition on the substrate. The perovskite precursor composition includes a solvent and one or more perovskite precursors, and removal of the solvent from the perovskite precursor composition produces a perovskite film on the substrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. patent application No. 63 / 479,025, filed January 9, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to methods and systems for depositing perovskite thin films. Background Art

[0004] Perovskite photovoltaic cells have been used alone as well as in combination with bottom cells to form tandem photovoltaic cells. Summary of the Invention

[0005] This disclosure describes methods and systems for depositing metal-halide perovskite thin films. The films can be deposited on any substrate that can be translated in a linear manner, including webs, wafers, and glass sheets. The resulting films are uniform and dense, have few defects, and have high external radiation efficiency, making them suitable for use in photovoltaic and other optoelectronic devices, and they can conform to textured surfaces. The methods and systems are scalable to coatings several meters wide, with production line throughputs of several meters per minute.

[0006] While the disclosed inventive concepts include those defined in the appended claims, it is to be understood that the inventive concepts can also be defined in accordance with the following embodiments.

[0007] Embodiment 1 is a method for forming a perovskite film on a substrate, the method comprising:

[0008] atomizing a perovskite precursor composition to produce perovskite precursor droplets, wherein the perovskite precursor composition comprises one or more perovskite precursors;

[0009] accelerating the perovskite precursor droplet toward the substrate at subatmospheric pressure;

[0010] collecting the perovskite precursor droplets on the substrate to produce a perovskite precursor layer on the substrate; and

[0011] A perovskite film is formed on the substrate from the perovskite precursor layer on the substrate, wherein the perovskite film has a crystal structure ABX3, wherein:

[0012] A represents one or more organic cations, one or more inorganic cations, or one or more of both,

[0013] B represents one or more metal cations, and

[0014] X represents one or more halogen anions.

[0015] Embodiment 2 is the method of embodiment 1, wherein the perovskite precursor composition further comprises a solvent.

[0016] Embodiment 3 is the method of embodiment 2, further comprising removing the solvent from the perovskite precursor droplets before or after collecting the perovskite precursor droplets on the substrate.

[0017] Embodiment 4 is the method of embodiment 3, wherein removing the solvent from the perovskite precursor droplets after collecting the perovskite precursor droplets on the substrate includes annealing the perovskite precursor layer, exposing the perovskite precursor layer to subatmospheric pressure, immersing or spraying the perovskite precursor layer with an antisolvent, or flowing a gas on top of the precursor layer.

[0018] Embodiment 5 is the method of embodiment 3 or 4, wherein removing the solvent from the perovskite precursor droplets after collecting the perovskite precursor droplets on the substrate comprises heating the substrate.

[0019] Embodiment 6 is the method of any one of embodiments 2 to 5, wherein the one or more perovskite precursors comprise one or more of methylammonium iodide, methylammonium bromide, methylammonium chloride, formamidine iodide, formamidine bromide, formamidine chloride, cesium iodide, cesium bromide, cesium chloride, lead (II) iodide, lead (II) bromide, lead (II) chloride, rubidium iodide, rubidium bromide, rubidium chloride, tin iodide, tin bromide, tin chloride, germanium iodide, germanium bromide, and germanium chloride.

[0020] Embodiment 7 is the method of embodiment 6, wherein the perovskite precursor composition further comprises one or more of phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, (benzylamine) trifluoroboron, tetradecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, and carbohydrazide.

[0021] Embodiment 8 is the method of any one of embodiments 2 to 7, wherein the solvent is a polar aprotic solvent.

[0022] Embodiment 9 is the method of embodiment 8, wherein the solvent comprises one or more of dimethyl sulfoxide, dimethylformamide, gamma-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol, and acetonitrile.

[0023] Embodiment 10 is the method of embodiment 2, wherein the perovskite precursor composition is a colloid.

[0024] Embodiment 11 is the method of embodiment 10, wherein the one or more perovskite precursors comprise one or more of methylammonium lead iodide, methylammonium tin iodide, methylammonium lead bromide, methylammonium tin bromide, methylammonium lead chloride, methylammonium tin chloride, formamidine lead iodide, formamidine tin iodide, formamidine lead bromide, formamidine tin bromide, formamidine lead chloride, formamidine tin chloride, cesium lead iodide, cesium tin iodide, cesium tin bromide, cesium tin bromide, cesium lead chloride, and cesium tin chloride.

[0025] Embodiment 12 is the method of embodiment 11, wherein the solvent is a non-polar solvent.

[0026] Embodiment 13 is the method of embodiment 12, wherein the solvent comprises one or more of hexane, octane, pentane, cyclohexane, benzene, and toluene.

[0027] Embodiment 14 is the method of any one of embodiments 1 to 13, wherein accelerating the perovskite precursor droplets toward the substrate comprises:

[0028] transporting the perovskite precursor droplets together with a carrier gas to a first vacuum chamber; and

[0029] The perovskite precursor droplet is expanded through a nozzle into a second vacuum chamber, wherein the pressure in the first vacuum chamber exceeds the pressure in the second vacuum chamber.

[0030] Embodiment 15 is the method of embodiment 14, wherein the pressure in the first vacuum chamber and the second vacuum chamber is in a range between about 0.001 Torr and about 1 Torr, between about 1 Torr and about 100 Torr, between about 100 Torr and about 300 Torr, or between about 300 Torr and about 760 Torr.

[0031] Embodiment 16 is the method of embodiment 15, wherein collecting the perovskite precursor droplets on the substrate comprises translating the substrate relative to the nozzle.

[0032] Embodiment 17 is the method of any one of embodiments 1 to 16, wherein the perovskite film is a continuous coating on the substrate.

[0033] Embodiment 18 is the method of any one of embodiments 1 to 17, wherein the perovskite film is a conformal coating on the substrate.

[0034] Embodiment 19 is the method of any one of embodiments 1 to 18, wherein the perovskite precursor droplets have a diameter between about 1 μm and about 10 μm, between about 0.002 μm and about 0.15 μm, between about 0.1 μm and about 8 μm, or between about 5 μm and about 80 μm.

[0035] Embodiment 20 is the method of any one of embodiments 1 to 19, wherein the perovskite film comprises perovskite grains having a size between about 0.05 μm and about 0.2 μm, between about 0.2 μm and about 2 μm, or between about 2 μm and about 100 μm.

[0036] Embodiment 21 is a coated substrate comprising:

[0037] substrate; and

[0038] a perovskite precursor composition on the substrate, wherein the perovskite precursor composition comprises a solvent and one or more perovskite precursors, and removing the solvent from the perovskite precursor composition produces a perovskite film on the substrate.

[0039] Embodiment 22 is the coated substrate of embodiment 21, wherein the one or more perovskite precursors comprise one or more of methylammonium iodide, methylammonium bromide, methylammonium chloride, formamidine iodide, formamidine bromide, formamidine chloride, cesium iodide, cesium bromide, cesium chloride, lead (II) iodide, lead (II) bromide, lead (II) chloride, rubidium iodide, rubidium bromide, rubidium chloride, tin iodide, tin bromide, tin chloride, germanium iodide, germanium bromide, and germanium chloride.

[0040] Embodiment 23 is the coated substrate of embodiment 22, wherein the perovskite precursor composition further comprises one or more of phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, (benzylamine) trifluoroboron, tetradecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, and carbohydrazide.

[0041] Embodiment 24 is the coated substrate of any one of embodiments 21 to 23, wherein the solvent is a polar aprotic solvent.

[0042] Embodiment 25 is the coated substrate of embodiment 24, wherein the solvent comprises one or more of dimethyl sulfoxide, dimethylformamide, gamma-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol, and acetonitrile.

[0043] Embodiment 26 is the coated substrate of any one of embodiments 21 to 25, wherein the one or more perovskite precursors comprise one or more of methylammonium lead iodide, methylammonium tin iodide, methylammonium lead bromide, methylammonium tin bromide, methylammonium lead chloride, methylammonium tin chloride, formamidine lead iodide, formamidine lead iodide, formamidine lead bromide, formamidine lead bromide, formamidine lead chloride, formamidine tin chloride, cesium lead iodide, cesium tin iodide, cesium tin bromide, cesium tin bromide, cesium lead chloride, and cesium tin chloride.

[0044] Embodiment 27 is the coated substrate of embodiment 26, wherein the solvent is a non-polar solvent.

[0045] Embodiment 28 is the coated substrate of embodiment 27, wherein the solvent comprises one or more of hexane, octane, pentane, cyclohexane, benzene, and toluene.

[0046] Embodiment 29 is a liquid deposition system comprising:

[0047] liquid delivery systems;

[0048] a nebulizer in fluid communication with the liquid delivery system;

[0049] a first chamber in fluid communication with the atomizer;

[0050] Second chamber;

[0051] a vacuum pump in fluid communication with the second chamber;

[0052] a nozzle, wherein the first chamber and the second chamber are in fluid communication through the nozzle; and

[0053] A substrate translation system is configured to translate a substrate relative to the nozzle such that atomized droplets accelerated from the first chamber to the second chamber through the nozzle form a layer on the substrate.

[0054] Embodiment 30 is the liquid deposition system of embodiment 29, further comprising:

[0055] additional fluid delivery systems;

[0056] an additional nebulizer in fluid communication with the additional liquid delivery system;

[0057] a third chamber in fluid communication with the additional atomizer; and

[0058] an additional nozzle, wherein the third chamber and the second chamber are in fluid communication through the nozzle,

[0059] wherein the substrate translation system is configured to translate the substrate relative to the additional nozzle such that atomized droplets accelerated from the third chamber to the second chamber through the nozzle form a layer on the substrate.

[0060] Advantages of the disclosed systems and methods include the following. The feedstock material is perovskite ink (unlike evaporation techniques), which can be adjusted to produce the desired film composition. The spray coating process distributes the droplets evenly over the substrate surface and does not introduce point or edge defects (unlike most other solution coating methods, such as slot-die coating). The process occurs in a rough vacuum, which allows the solvent in the droplets to partially or completely evaporate before the droplets are deposited, which in turn enables conformal deposition of textured surfaces (unlike atmospheric pressure spray techniques). The process can be inline or continuous, making it compatible with roll-to-roll and sheet-to-sheet processing.

[0061] The details of one or more implementations of the subject matter of the present disclosure are set forth in the accompanying drawings and the description. Other features, aspects, and advantages of the subject matter will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a schematic diagram of a first embodiment of a spraying system.

[0063] Figure 2 is a schematic diagram of a second embodiment of a spraying system.

[0064] Figure 3 is a schematic diagram of a third embodiment of a spraying system. DETAILED DESCRIPTION

[0065] This disclosure describes a method for spraying perovskite ink in a low vacuum environment. As used herein, "low vacuum" generally refers to an enclosure with a relatively smaller number of air particles than standard atmospheric pressure, and the pressure can be as low as 10 -3 As used herein, "spray coating" generally refers to the process of atomizing perovskite ink, accelerating perovskite droplets from a high-pressure chamber to a low-pressure chamber (e.g., where both chambers are under a low vacuum), and then depositing them onto a moving substrate. As used herein, "perovskite ink" generally refers to a liquid solution that can be converted into a solid film having a perovskite crystal structure of ABX3 (e.g., when the solvent evaporates and the solute is left behind), where A is an organic or inorganic cation or a mixture of cations, B is a metal cation or a mixture of cations, and X is a halogen anion or a mixture of anions.

[0066] To spray perovskite ink, a liquid delivery system delivers the ink to an atomizer. As used herein, a "liquid delivery system" generally refers to a device that draws perovskite ink from a source and feeds it into an atomizer. As used herein, an "atomizer" generally refers to a device that converts perovskite ink into micron- to nanometer-sized droplets.

[0067] Once the perovskite ink is atomized, a carrier gas transports the droplets into a high-pressure chamber. As used herein, a "high-pressure chamber" generally refers to an enclosure of any shape under a low vacuum. Once the perovskite droplets enter the high-pressure chamber, they are accelerated toward the low-pressure chamber due to the pressure difference between the two chambers. As used herein, a "low-pressure chamber" generally refers to an enclosure of any shape under a low vacuum that is connected to the high-pressure chamber but has a lower pressure. This pressure difference is created by connecting the two chambers with a nozzle. As used herein, a "nozzle" generally refers to an opening of any shape that is small enough to restrict the flow of incoming perovskite droplets and create a pressure difference between the two chambers.

[0068] After the perovskite droplets are accelerated through the nozzle and enter the low-pressure chamber, they impact the moving substrate on its side facing the nozzle to produce a perovskite film. As used herein, "perovskite film" generally refers to a solid layer having a perovskite crystal structure of ABX3, where A is an organic or inorganic cation or a mixture of cations, B is a metal cation or a mixture of cations, and X is a halogen anion or a mixture of anions. As used herein, "substrate" generally refers to any solid material with a patterned or flat surface. The movement of the substrate is controlled by a substrate translation system. As used herein, "substrate translation system" generally refers to a device that moves a substrate linearly along one or more directions.

[0069] Once the spraying of the perovskite ink is complete, the result can be a wet film or a dry film. As used herein, a "wet film" generally refers to a layer that still contains both the solvent and solute of the perovskite ink. As used herein, a "dry film" generally refers to a layer that contains only the solute of the perovskite ink (e.g., the solvent has evaporated from the perovskite droplets before impacting the substrate). If a wet film is obtained, one or more post-deposition treatments can be performed to produce a perovskite film. As used herein, a "post-deposition treatment" generally refers to a process that evaporates or extracts the remaining solvent of the sprayed film to allow perovskite crystals to nucleate and grow into a perovskite film. If a dry film is obtained, the perovskite film has been formed and the post-deposition treatment is optional.

[0070] Although about Figures 1 to 3 Examples of spraying arrangements and processes are described, but other embodiments may have one or more additional components, or may omit one or more components. In some embodiments, the same components may be arranged in a different order. In other embodiments, one or more process conditions may be modified.

[0071] Figure 1 is a schematic diagram of a spray coating setup 100. The spray coating setup 100 includes a perovskite ink 102, a liquid delivery system 108, a carrier gas 110, an atomizer 112, a high pressure chamber 200, a nozzle 202, a low pressure chamber 300, a perovskite film 302, a substrate 306, a substrate translation system 308, and a vacuum pump valve 310.

[0072] The liquid delivery system 108 is configured to deliver the perovskite ink 102 to the atomizer 112 at a flow rate between about 0.01 ml / min and about 500 ml / min, for example, at a flow rate between about 0.1 ml / min and about 10 ml / min at a low flux (e.g., 0.25 m / min) for spraying a small substrate 306 (e.g., having a width of about 2.5 cm), and at a flow rate between about 20 ml / min and about 200 ml / min at a high flux (e.g., 15 m / min) for spraying a large substrate 306 (e.g., having a width of about 15 cm). The optimal value may depend at least in part on the concentration of the perovskite ink 102, the width of the substrate 306, the desired thickness of the perovskite film 302, the desired yield of the spraying setup 100, the desired flux of the spraying setup 100, and the type of equipment used for the atomizer 112. The liquid delivery system 108 should be capable of continuous operation without clogging for a minimum of about 1 month.

[0073] In some embodiments, the liquid delivery system 108 comprises a syringe pump having a flow rate of about 10 -8 ml / min and a flow rate between about 150 ml / min. In other embodiments, the liquid delivery system 108 includes a peristaltic pump having a flow rate between about 0.05 ml / min and about 1000 mL / min. In other embodiments, the liquid delivery system 108 includes a pressure-driven pump that pressurizes the sealed liquid reservoir with gas to push the perovskite ink 102 through the tube and into the atomizer 112. The pump has a flow rate between about 0.1 ml / min and about 100 mL / min, which is controlled by adjusting the pressure difference between the inside of the sealed reservoir and the outlet. In other embodiments, the liquid delivery system 108 includes a small diaphragm pump having a flow rate between about 100 ml / min and about 1000 ml / min. In other embodiments, the liquid delivery system 108 includes any positive pump or non-positive pump having a flow rate greater than 0.1 ml / min.

[0074] The perovskite ink 102 is configured as a mixture that is converted into a perovskite film 302 after being sprayed onto the substrate 306, followed by post-deposition processing if necessary. In some embodiments, the perovskite ink 102 is a solution of a soluble solute having a diameter of less than about 1 nm. The solute is a perovskite precursor including methylammonium iodide, methylammonium bromide, formamidine iodide, formamidine bromide, cesium iodide, lead (II) iodide, lead (II) bromide, rubidium iodide, tin iodide, germanium iodide, any combination thereof, or any other suitable perovskite precursor. To improve the quality of the perovskite film 302, solute additives such as phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, carbohydrazide, any combination thereof, or any other suitable additive can be added to the perovskite ink 102. To dissolve the solute, a polar aprotic solvent is typically used, such as dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol, acetonitrile, any combination thereof, or any other suitable solvent. The choice of solute and solvent may depend at least in part on the desired morphology of the perovskite film 302 and its optoelectronic properties.

[0075] In other embodiments, the perovskite ink 102 is a colloid of insoluble colloidal particles having a diameter greater than or equal to about 1 nm. These particles are perovskite crystals having an ABX3 crystal structure suspended in a solvent, where A is an organic or inorganic cation or a mixture of cations, B is a metal cation or a mixture of cations, and X is a halogen anion or a mixture of anions. The colloidal particles are composed of methylammonium lead iodide, methylammonium lead bromide, methylammonium lead chloride, formamidine lead iodide, formamidine lead bromide, formamidine lead chloride, cesium lead iodide, cesium lead bromide, cesium lead chloride, cesium tin iodide, any combination thereof, or any other suitable perovskite compound. To suspend the colloidal particles, a non-polar solvent is typically used, such as hexane, octane, pentane, cyclohexane, benzene, toluene, any combination thereof, or any other suitable solvent. The optimal choice of colloidal particles and solvent may depend at least in part on the desired morphology of the perovskite film 302 and its optoelectronic properties.

[0076] Controlling the temperature of the perovskite ink 102 can be a parameter that can be varied to help achieve the desired morphology and optoelectronic properties of the perovskite film 302. In some embodiments, the perovskite ink 102 is temperature-controlled to be between approximately -20°C and approximately 200°C, for example, between approximately 10°C and approximately 28°C to match the inner wall temperatures of the high-pressure chamber 200 and the low-pressure chamber 300 so that the perovskite droplets do not condense on the chamber walls and thus avoid large droplets (i.e., millimeter-sized) being deposited on the substrate 306; or between approximately 30°C and approximately 120°C to increase the solubility of the perovskite ink 102 so that for a wet film undergoing post-deposition processing, the perovskite crystal nucleation rate is reduced while the growth rate remains relatively the same to obtain large grains of the perovskite film 302; or between approximately 70°C and approximately 180°C to increase the solvent evaporation rate of the perovskite droplets to obtain a dried perovskite film 302. The optimal temperature of the perovskite ink 102 may depend at least in part on the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, the desired degree of wetness or dryness of the film after spraying, and the desired morphology and optoelectronic properties of the perovskite film 302. In other embodiments, the perovskite ink 102 is not temperature controlled.

[0077] The atomizer 112 is configured to break up the perovskite ink 102 entering via the liquid delivery system 108 into droplets having a diameter between about 0.001 μm and about 1000 μm, for example, droplets between about 0.2 μm and about 1 μm to obtain a drier film (i.e., because smaller droplets require less solvent evaporation before the dry solute reaches the substrate 306), and droplets between about 5 μm and about 100 μm to obtain a wetter film. In addition, when sprayed on a patterned substrate 306, smaller perovskite droplets generally result in a more conformal perovskite film 302, at least because dry solutes adhere more strongly to the patterned surface than wet solutes. The droplet size can be at least 10 times smaller than the size of the pattern features, making it possible to achieve a conformal film with high surface coverage.

[0078] Controlling the droplet size distribution produced by the atomizer 112 is a parameter that can be varied to help achieve the desired morphology and optoelectronic properties of the perovskite film 302. Generally, the narrower the droplet size distribution, the more uniform the perovskite film 302 will be morphologically. In some embodiments, the atomizer 112 is a monodisperse device that produces uniform droplet sizes with a geometric standard deviation of less than or equal to approximately 1.25. In other embodiments, the atomizer 112 is a polydisperse device that produces non-uniform droplet sizes with a geometric standard deviation greater than approximately 1.25. The optimal droplet size or size distribution can depend at least in part on the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102 (if the perovskite ink 102 is a colloid or solution), the desired degree of wetness or dryness of the film after spraying, the desired degree of conformality of the perovskite film 302 on the substrate 306 having a patterned top surface, the desired morphology and optoelectronic properties of the perovskite film 302, and the pressures within the high-pressure chamber 200 and the low-pressure chamber 300.

[0079] In some embodiments, the nebulizer 112 comprises a collision nebulizer that produces a droplet size between about 1 μm and about 10 μm. In other embodiments, the nebulizer 112 comprises an electrospray-based aerosol generation technology that produces a droplet size between about 0.002 μm and about 0.15 μm. In other embodiments, the nebulizer 112 comprises a condensation-based aerosol generation technology that produces a droplet size between about 0.1 μm and about 8 μm. In other embodiments, the nebulizer 112 comprises an ultrasonic nozzle that produces a droplet size between about 5 μm and about 80 μm. In other embodiments, the nebulizer 112 comprises any other suitable device that produces monodisperse or polydisperse droplets with a diameter between about 0.001 μm and about 1000 μm.

[0080] The carrier gas 110 is configured to transport the perovskite droplets (i.e., with low chemical reactivity) from the atomizer 112 to the high-pressure chamber 200 and control the pressure within the chamber. The pressure within the high-pressure chamber 200 is a parameter that influences the wetness or dryness of the sprayed film. Increasing the flow rate of the carrier gas 110 increases the pressure within the high-pressure chamber 200. This, in turn, reduces the solvent evaporation rate of the perovskite droplets traveling from the atomizer 110 to the substrate 306. Conversely, reducing the flow rate of the carrier gas 110 reduces the pressure within the high-pressure chamber 200 and increases the solvent evaporation rate of the perovskite droplets. Therefore, to achieve a wet film, the pressure within the high-pressure chamber 200 is typically between approximately 100 Torr and approximately 400 Torr. To achieve this, the carrier gas 110 typically has a flow rate between approximately 30 SLM and approximately 400 SLM. On the other hand, to achieve a dry film, the pressure within the high-pressure chamber 200 is typically between approximately 1 Torr and approximately 90 Torr. To achieve this, the carrier gas 110 typically has a flow rate between about 0.1 SLM and about 25 SLM. The optimal flow rate may depend at least in part on the size of the high pressure chamber 200, the opening size of the nozzle 202, the type of equipment used for the atomizer 112, the vacuum pumping capacity, the position of the vacuum pump valve 310, and the desired degree of wetness or dryness of the film after spraying. The carrier gas 110 can be nitrogen, helium, argon, hydrogen, air, any combination thereof, or any other suitable gas.

[0081] Controlling the temperature of the carrier gas 110 is another parameter that influences the wetness or dryness of the sprayed film. In some embodiments, the carrier gas 110 is temperature-controlled to a range of approximately -100°C to approximately 500°C, for example, between approximately 0°C and approximately 20°C to reduce the solvent evaporation rate of the perovskite droplets and achieve a wetter film, or between approximately 25°C and approximately 40°C to match the inner wall temperature of the high-pressure chamber 200 and the low-pressure chamber 300 to the temperature of the perovskite droplets so that they do not condense on the chamber walls, thereby preventing large droplets (i.e., millimeter-sized) from depositing on the substrate 306, or between approximately 35°C and approximately 150°C to increase the solvent evaporation rate of the perovskite droplets and achieve a drier film. The optimal temperature of the carrier gas 110 may depend, at least in part, on the desired wall temperatures of the high-pressure chamber 200 and the low-pressure chamber 300, the desired wetness or dryness of the sprayed film, and the desired morphology and optoelectronic properties of the perovskite film 302. In other embodiments, the carrier gas 110 is not temperature controlled.

[0082] In some embodiments, if the equipment used for the nebulizer 112 requires a gas input to function properly and pressure control of the high pressure chamber 200 is desired, the carrier gas 110 can be introduced into the nebulizer 112 and the high pressure chamber 200. In this case, in some embodiments, the type of gas used for the carrier gas 110 and its flow rate are the same for the nebulizer 112 and the high pressure chamber 200. In other embodiments, the type of gas used for the carrier gas 110 is the same for the nebulizer 112 and the high pressure chamber 200, but their flow rates are different. In other embodiments, the type of gas used for the carrier gas 110 is different for the nebulizer 112 and the high pressure chamber 200, but their flow rates are the same. In other embodiments, the type of gas used for the carrier gas 110 and its flow rate are different for the nebulizer 112 and the high pressure chamber 200.

[0083] In other embodiments, the carrier gas 110 may only be introduced into the nebulizer 112 if the equipment for the nebulizer 112 requires a gas input to function properly and pressure control of the high pressure chamber 200 is not desired.

[0084] In other embodiments, if the equipment for the nebulizer 112 does not require gas input to function properly and pressure control of the high pressure chamber 200 is desired, the carrier gas 110 may simply be introduced into the high pressure chamber 200 .

[0085] To obtain the perovskite film 302, the velocity of the perovskite droplets traveling from the atomizer 112 to the substrate 306 is significantly increased to a velocity equal to or greater than about Mach 1 so that they adhere to the surface of the substrate 306 upon impact. This can be achieved by increasing the pressure near the atomizer 112 and maintaining or reducing the pressure near the substrate 306. As the perovskite droplets approach the substrate 306, this pressure differential will accelerate the perovskite droplets to a higher velocity.

[0086] exist Figure 1 In the embodiment, a pressure difference is generated by using a high pressure chamber 200, a nozzle 202, a low pressure chamber 300 and a vacuum pump valve 310. The high pressure chamber 200 is configured as a shell having any material, shape and size, and the internal pressure thereof is equal to or higher than 10 -3 The high-pressure chamber 200 is supported and higher than the low-pressure chamber 300. The material of the high-pressure chamber 200 can be metal, plastic, glass, or any other suitable material having low chemical reactivity with the perovskite ink 102. The shape of the high-pressure chamber 200 can be a cuboid, a cylinder, a cube, a cone, any combination thereof, or any other suitable shape having a clear path from its inlet to its outlet.

[0087] The nozzle 202 is configured as a convergent or convergent-divergent nozzle connecting the high-pressure chamber 200 and the low-pressure chamber 300. It can have any material, shape opening, and size opening that restricts the flow of the perovskite droplets. The material of the nozzle 202 can be metal, plastic, glass, or any other suitable material with low chemical reactivity with the perovskite ink 102. The shape opening of the nozzle 202 can be a slit or multiple slits, a circle or multiple circles, a square or multiple squares, a ring or multiple rings, any combination thereof, or any other suitable shape opening. The opening size of the nozzle 202 is advantageously small enough to generate a pressure difference between the high-pressure chamber 200 and the low-pressure chamber 300, which is sufficient to cause the perovskite droplets to reach a minimum speed of about Mach 1 when impacting the substrate 306.

[0088] The low pressure chamber 300 is configured as a shell having any material, shape and size, and the internal pressure thereof is equal to or higher than 10 -3 The low-pressure chamber 300 is shaped like a rectangular parallelepiped, a cylinder, a cube, a cone, any combination thereof, or any other suitable shape having a clear path for the substrate translation system 308 to linearly move the substrate 306 within the chamber.

[0089] The vacuum pump valve 310 is configured to control the pumping capacity of the vacuum pump connected to the low-pressure chamber 300. The vacuum pump valve 310 can be a butterfly valve, a gate valve, a slit valve, an angle valve, a ball valve, any combination thereof, or any other suitable valve. In some embodiments, the vacuum pump valve 310 is manually actuated. In other embodiments, the vacuum pump valve 310 is pneumatically actuated. In other embodiments, the vacuum pump valve 310 is electrically actuated. In other embodiments, the vacuum pump valve 310 is actuated using any combination of the aforementioned methods or any other suitable method or methods.

[0090] When the vacuum pump valve 310 is fully open, the pressure inside the high-pressure chamber 200 and the low-pressure chamber 300 will drop to the same value; this value will depend on the pumping capacity of the vacuum pump being used. When the nozzle 202 is introduced to connect the two chambers, it creates a flow restriction for the incoming perovskite droplets from the atomizer 112; thus, the pressure inside the high-pressure chamber 200 will increase, while the pressure inside the low-pressure chamber 300 will remain relatively the same. The pressure ratio (i.e., the ratio of the pressure inside the high-pressure chamber 200 to the pressure inside the low-pressure chamber 300) is an important parameter for controlling the acceleration of the perovskite droplets from the high-pressure chamber 200 to the low-pressure chamber 300. The optimal pressure ratio may depend at least in part on the desired perovskite droplet velocity upon impact with the substrate 306 and the desired yield of the spraying setup 100. In some embodiments, the pressure ratio can be reduced by increasing the opening size of the nozzle 202, reducing the flow rate of the carrier gas 110, reducing the vacuum pumping capacity using the vacuum pump valve 310, any combination thereof, or any other suitable method. In other embodiments, the pressure ratio may be increased by reducing the opening size of the nozzle 202 , increasing the flow rate of the carrier gas 110 , increasing the vacuum pumping capacity using the vacuum pump valve 310 , any combination thereof, or any other suitable method.

[0091] In some embodiments, the nozzle 202, the high pressure chamber 200, and the low pressure chamber 300 are all separate components. In other embodiments, the nozzle 202 and the high pressure chamber 200 are all one component, and the low pressure chamber 300 is a separate component. In other embodiments, the nozzle 202 and the low pressure chamber 300 are all one component, and the high pressure chamber 200 is a separate component. In other embodiments, the nozzle 202, the high pressure chamber 200, and the low pressure chamber 300 are all one component.

[0092] The temperature of the walls of the high-pressure chamber 200 and the low-pressure chamber 300 can be controlled to help achieve the desired morphology and optoelectronic properties of the perovskite film 302. In some embodiments, the walls of the high-pressure chamber 200 and the low-pressure chamber 300 are temperature-controlled to a temperature between approximately -200°C and approximately 500°C, for example, between approximately 0°C and approximately 20°C to reduce the solvent evaporation rate of the perovskite droplets to achieve a wetter film, or between approximately 20°C and approximately 80°C to match the perovskite droplet temperature so that they do not condense on the chamber walls and thus avoid large droplets (i.e., millimeter-sized) from being deposited on the substrate 306, or between approximately 30°C and approximately 200°C to increase the solvent evaporation rate of the perovskite droplets to achieve a drier film. The optimal wall temperature of the high-pressure chamber 200 and the low-pressure chamber 300 depends at least in part on the perovskite droplet temperature, the desired degree of wetness or dryness of the film after spraying, and the desired morphology and optoelectronic properties of the perovskite film 302. In other embodiments, only the walls of the high pressure chamber 200 are temperature controlled. In other embodiments, only the walls of the low pressure chamber 300 are temperature controlled. In other embodiments, the walls of the high pressure chamber 200 and the low pressure chamber 300 are not temperature controlled.

[0093] The substrate 306 is configured as a surface onto which the perovskite ink 102 is sprayed to produce the perovskite film 302. It can be any solid material with a patterned or flat surface and can include one or more materials. The substrate 306 can be glass, silicon, plastic, metal, any combination thereof, or any other suitable material. The substrate 306 can also have one or more layers on top of its nozzle-facing surface. The outermost layer on the surface can be nickel oxide, tin oxide, zinc oxide, copper oxide, copper (I) iodide, silicon oxide, zirconium oxide, titanium oxide, indium tin oxide, indium zinc oxide, indium hydride oxide, indium tungsten oxide, indium cerium oxide, zinc tin oxide, poly (bis (4-phenyl) (2,4,6-trimethylphenyl) amine, poly (N,N'-bis-4-butylphenyl-N,N'-diphenyl) benzidine, 2,2',7,7'-tetrakis (N,N-di-p-methoxyphenyl-amine) 9,9'-spirobifluorene, poly (3,4-ethylenedioxythiophene) polystyrene sulfonate, poly (3-hexylthiophene-2,5-diyl), buckminsterfullerene, any combination thereof, or any other suitable layer. The distance between the nozzle 202 and the substrate 306 can affect the velocity of the perovskite droplet when the substrate 306 impacts. This distance is typically between about 0.5 mm and about 100 mm, such as between about 1 mm and about 5 mm, to maximize yield and solute adhesion on the substrate 306, or between about 10 mm and about 50 mm to reduce the droplet impact intensity for softer deposition of the perovskite ink 102. The optimal distance may depend, at least in part, on the desired perovskite droplet velocity upon impact with the substrate 306, the desired yield of the spraying setup 100, and the desired morphology of the perovskite film 302 and its optoelectronic properties.

[0094] The substrate translation system 308 is configured to linearly move the substrate 306 beneath the nozzle 202 to produce the perovskite film 302. The translation of the substrate 306 can be along one or more axes, and for each axis, the movement can be in one direction or back and forth beneath the nozzle 202. The translation speed is typically between about 0.001 m / min and about 50 m / min, for example, between about 10 m / min and about 25 m / min for high-throughput applications (e.g., solar cell manufacturing). The optimal translation speed of the substrate 306 can depend at least in part on the desired throughput of the spraying setup 100, the concentration of the perovskite ink 102, and the desired thickness of the perovskite film 302.

[0095] In some embodiments, substrate translation system 308 includes a platform and a motion system. The platform can be any solid material positioned below (e.g., directly below) substrate 306 to support its weight and secure it from movement during the spraying process. The motion system can include a stepper motor, a brushed DC motor, a brushless DC motor, a DC servo motor, an AC servo motor, a piezoelectric motor, any combination thereof, or any other suitable device. In some embodiments, the motion system can also rotate the platform. In other embodiments, the motion system can also tilt the platform. In other embodiments, the motion system can also rotate and tilt the platform.

[0096] In other embodiments, substrate translation system 308 includes rollers to linearly move substrate 306. In this case, the rollers are positioned below substrate 306 and are constructed of metal, plastic, glass, or any other suitable material. In some embodiments, some of the rollers are powered to translate substrate 306. In other embodiments, all of the rollers are powered to translate substrate 306.

[0097] In other embodiments, the substrate translation system 308 includes a roll-to-roll translation process to linearly move the substrate 306. In this case, the substrate 306 is a roll of plastic, metal, any other flexible and suitable material, or any other flexible and suitable material having one or more layers on its nozzle-facing surface. The rollers can be constructed of metal, plastic, glass, or any other suitable material.

[0098] In other embodiments, substrate translation system 308 includes any other suitable method that can linearly move substrate 306 beneath nozzle 202 to produce perovskite film 302 .

[0099] The substrate translation system 308 can also be configured to control the temperature of the substrate 306. This enables rapid in-situ control of solvent evaporation of the wet perovskite droplets once they are deposited onto the substrate 306. This immediate control over the nucleation and growth rates of the perovskite crystals generally results in a more uniform perovskite film 302 morphology. In some embodiments, the substrate 306 is temperature controlled between about -300° C. and about 500° C., for example, between about -300° C. and about -150° C., to freeze the deposited wet film and significantly increase the nucleation rate compared to the growth rate of the perovskite crystals during the post-deposition treatment to obtain small grains of the perovskite film 302 (i.e., between about 0.05 μm and about 0.2 μm), and, if necessary, between about 30° C. and about 100° C., to increase the nucleation rate and growth rate of the perovskite crystals to obtain medium-sized grains of the perovskite film 302 (i.e., between about 0.2 μm and about 2 μm) after the post-deposition treatment, and, if necessary, between about 100° C. and about 200° C., to significantly increase the growth rate compared to the nucleation rate of the perovskite crystals to obtain large grains of the perovskite film 302 (i.e., between about 2 μm and about 100 μm) after the post-deposition treatment. The optimal temperature of the substrate 306 may depend at least in part on the concentration of the perovskite ink 102 , the chemical composition of the perovskite ink 102 , the desired degree of wetness or dryness of the film after spraying, and the desired morphology of the perovskite film 302 and its optoelectronic properties.

[0100] In some embodiments, the platform, rollers, or any other component of the substrate translation system 308 is temperature controlled by resistive heating, liquid and / or gas heating and cooling, or any combination thereof, to control the temperature of the substrate 306. In other embodiments, one or more heat lamps are used to control the temperature of the substrate 306. In other embodiments, any other suitable method is used to control the temperature of the substrate 306.

[0101] Once the spraying of the perovskite ink 102 is complete, a post-deposition process may be performed to obtain the perovskite film 302. If the spraying process produces a dry film, the perovskite film 302 is already formed and post-deposition processing is generally not required. However, if a change in morphology or optoelectronic properties is desired, post-deposition processing may be performed. On the other hand, if the spraying process produces a wet film, post-deposition processing may be performed to evaporate or extract the remaining solvent and convert it into the perovskite film 302.

[0102] In some embodiments, the post-deposition treatment is a vacuum quench, in which the sprayed film is left inside an enclosure under vacuum to evaporate the remaining solvent. This post-deposition treatment is a good choice if medium-sized grains (i.e., between about 0.2 μm and about 2 μm) are desired for the perovskite film 302. To quench the sprayed film, the vacuum pressure is typically between about 700 Torr and about 10 -4Torr, for example, for slow solvent evaporation rates that typically produce larger and less uniform grain sizes of the perovskite film 302, the vacuum pressure is between 200 Torr and about 10 -10 Torr, or for a fast solvent evaporation rate that generally produces smaller and more uniform grain sizes of the perovskite film 302, the vacuum pressure is between about 5 Torr and about 10 -3 The quenching time is typically between about 1 s and about 600 s, for example, between 1 s and about 60 s to nucleate perovskite crystals but without completely evaporating the solvent if subsequent post-deposition processing is desired to obtain the perovskite film 302, or between about 120 s and about 600 s to nucleate and grow perovskite crystals by completely evaporating the solvent to obtain the perovskite film 302 without subsequent post-deposition processing. The optimal vacuum pressure and quenching time may depend at least in part on the type of one or more solvents used for the perovskite ink 102, the amount of solvent remaining after spraying, the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, whether one or more subsequent processing will be followed, the desired grain size of the perovskite film 302, the desired morphology of the perovskite film 302, and the desired optoelectronic properties of the perovskite film 302. In certain embodiments, the vacuum quenching is performed inside the low-pressure chamber 300 and below the nozzle 202 without spraying the perovskite ink 102. In other embodiments, vacuum quenching is performed inside the low pressure chamber 300 and away from the nozzle 202, with or without spraying the perovskite ink 102. In other embodiments, vacuum quenching is accomplished under vacuum inside any other suitable enclosure.

[0103] In other embodiments, the post-deposition treatment is annealing of the sprayed film to evaporate the remaining solvent. This post-deposition treatment is a good choice if large grains (e.g., between about 2 μm and about 100 μm) are desired for the perovskite film 302. To anneal the sprayed film, the temperature of the substrate 306 is typically between about 30°C and about 500°C, for example, between about 30°C and about 80°C for a slow solvent evaporation rate that typically produces a continuous perovskite film 302 with large grains, or between about 100°C and about 150°C for a moderate solvent evaporation rate that typically produces a discontinuous perovskite film 302 with large grains separated from each other, or between about 180°C and about 250°C for a moderate solvent evaporation rate that typically produces a discontinuous perovskite film 302 with very large perovskite grains separated from each other. The annealing time is typically between about 0.01 minutes and about 120 minutes, for example, between about 0.1 minutes and about 5 minutes to allow nucleation and growth of perovskite crystals without complete evaporation of the solvent if subsequent post-deposition processing is desired to obtain the perovskite film 302, or between about 10 minutes and about 60 minutes to allow nucleation and growth of perovskite crystals by complete evaporation of the solvent to obtain the perovskite film 302 without subsequent post-deposition processing. The optimal annealing temperature and time may depend at least in part on the type of one or more solvents used for the perovskite ink 102, the amount of solvent remaining after spraying, the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, whether one or more subsequent processing will be followed, the desired grain size of the perovskite film 302, the desired morphology of the perovskite film 302, and the desired optoelectronic properties of the perovskite film 302. In some embodiments, the annealing is performed inside the low-pressure chamber 300 and below the nozzle 202 without spraying the perovskite ink 102. In other embodiments, annealing is performed inside the low pressure chamber 300 and away from the nozzle 202, with or without spraying the perovskite ink 102. In other embodiments, annealing is performed under vacuum, in an ambient atmosphere, or in another suitable environment within another enclosure. The annealing apparatus can be a hot plate, a furnace, a heat lamp, any combination thereof, or any other suitable apparatus. In some embodiments, the annealing apparatus is a subcomponent of the substrate translation system 308. In other embodiments, the annealing apparatus is a separate component from the substrate translation system 308.

[0104] In other embodiments, the post-deposition treatment is a gas quench, in which the sprayed film is further dried by blowing a gas over its top to evaporate the remaining solvent. This post-deposition treatment is a good choice if medium-sized grains (i.e., between about 0.2 μm and about 2 μm) are desired for the perovskite film 302. Since such a treatment typically only partially evaporates the solvent from the sprayed film, a subsequent post-deposition treatment may be required. The gas may be air, nitrogen, helium, argon, hydrogen, any combination thereof, or any other suitable gas. To quench the sprayed film, the distance between the film and the gas outlet needs to be between about 0.001 cm and about 30 cm, for example, between about 0.01 cm and about 5 cm for a fast solvent evaporation rate, which generally results in a smaller and more uniform grain size of the perovskite film 302, or between about 10 cm and about 20 cm for a slow solvent evaporation rate, which generally results in a larger and more non-uniform grain size of the perovskite film 302. In addition, the gas flow rate may be between about 0.1 SLM and about 300 SLM, for example, between about 5 SLM and about 50 SLM for a slow solvent evaporation rate that typically produces larger and more non-uniform grain sizes for the perovskite film 302, or between about 100 SLM and about 200 SLM for a fast solvent evaporation rate that typically produces smaller and more uniform grain sizes for the perovskite film 302. The quenching time may be between about 0.5 s and about 600 s, for example, between about 1 s and about 240 s to allow perovskite crystals to nucleate but not completely evaporate the solvent, thus typically requiring subsequent post-deposition processing to obtain the perovskite film 302, and between about 420 s and about 600 s to allow perovskite crystals to nucleate and grow but not completely evaporate the solvent, thus typically requiring subsequent post-deposition processing to obtain the perovskite film 302. In some embodiments, the gas temperature is controlled between about 20° C. and about 300° C., such as between about 30° C. and about 80° C., to increase the solvent evaporation rate, which generally results in a smaller and more uniform grain size of the perovskite film 302, or between about 100° C. and 250° C. to increase solvent evaporation and increase the growth rate of the perovskite crystals, which generally results in a larger and more non-uniform grain size of the perovskite film 302. In other embodiments, the gas is not temperature controlled.

[0105] The optimal distance between the sprayed film and the gas outlet, the gas flow rate, the quenching time, and the gas temperature may depend, at least in part, on the type of solvent(s) used for the perovskite ink 102, the amount of solvent remaining after spraying, the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, the one or more subsequent treatments to be followed, the desired grain size of the perovskite film 302, the desired morphology of the perovskite film 302, and the desired optoelectronic properties of the perovskite film 302. In certain embodiments, by using Figure 1Instead of spraying the perovskite ink 102, the gas quenching is performed inside the low pressure chamber 300 using the spraying arrangement 100 and the flowing carrier gas 110 disclosed in Figure 1 The spraying setup 100 disclosed in

[15] is described in detail and adds a second set of high-pressure chambers 200 and nozzles 202 in series with the first original set to flow the carrier gas 110 through the second set, with gas quenching being performed inside the low-pressure chamber 300. In this case, the substrate 306 translates beneath the first nozzle 202 to be sprayed with the perovskite ink 102, and then continues to translate inline beneath the second nozzle 202 to be quenched with the gas. In other embodiments, the gas quench is performed inside the low-pressure chamber 300 by adding any suitable device in series with the high-pressure chamber 200 and nozzles 202 to flow the gas after spraying the perovskite ink 102. In other embodiments, the gas quench can be performed within another enclosure under vacuum, in an ambient atmosphere, or in any other suitable environment using any suitable device that can flow the gas. In some embodiments, the substrate 306 translates in one direction or back and forth beneath the gas outlet during quenching. In other embodiments, the substrate 306 is stationary beneath the gas outlet during quenching.

[0106] In other embodiments, the post-deposition treatment is an anti-solvent bath quench, in which the sprayed film is immersed in a bath to extract the remaining solvent. This post-deposition treatment is a good choice if medium-sized grains (e.g., between about 0.2 μm and about 2 μm) are desired for the perovskite film 302. Since this treatment can only partially extract the solvent from the sprayed film, a subsequent post-deposition treatment is typically required. The anti-solvent bath can be ethanol, isopropyl alcohol, butanol, ethyl acetate, methyl acetate, chloroform, chlorobenzene, butyl acetate, 1,2-dichlorobenzene, anisole, trifluorotoluene, ethyl ether, m-xylene, toluene, mesitylene, any combination thereof, or any other suitable anti-solvent bath. To quench the sprayed film, the antisolvent bath typically has a dipole moment between about 0.1 D and about 3.5 D, such as between about 0.5 D and about 1.2 D for a slow solvent extraction rate, which generally produces a larger and more non-uniform grain (gain) size of the perovskite film 302, and between about 1.5 D and about 3 D for a fast solvent extraction rate, which generally produces a smaller and more uniform grain size of the perovskite film 302.

[0107] The quenching time is typically between about 1 s and about 900 s, for example, between about 1 s and about 30 s to allow perovskite crystals to nucleate but not completely extract the solvent, and therefore, a subsequent post-deposition treatment is typically required to obtain the perovskite film 302, and between about 120 s and about 360 s to allow perovskite crystals to nucleate and grow but not completely evaporate the solvent, and therefore, a subsequent post-deposition treatment is typically required to obtain the perovskite film 302.

[0108] In some embodiments, the antisolvent bath temperature is controlled between about -20°C and about 150°C, for example, between about -10°C and about 10°C, to slow the solvent extraction rate, which generally results in larger and more non-uniform grain sizes of the perovskite film 302, or between about 30°C and 80°C to accelerate the solvent extraction rate, which generally results in smaller and more uniform grain sizes of the perovskite film 302. In other embodiments, the antisolvent bath is not temperature controlled.

[0109] The optimal anti-solvent bath composition, quenching time, and bath temperature may depend at least in part on the type of solvent(s) used for the perovskite ink 102, the amount of solvent remaining after spraying, the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, the one or more subsequent treatments to follow, the desired grain size of the perovskite film 302, the desired morphology of the perovskite film 302, and the desired optoelectronic properties of the perovskite film 302.

[0110] In certain embodiments, the antisolvent bath quench is performed inside the low-pressure chamber 300 and below the nozzle 202 without spraying the perovskite ink 102. In other embodiments, the antisolvent bath quench is performed inside the low-pressure chamber 300 and away from the nozzle 202, with or without spraying the perovskite ink 102. In other embodiments, the antisolvent bath quench is performed inside another enclosure under vacuum, in an ambient atmosphere, or in any other suitable environment. In some embodiments, the substrate 306 is translated into and out of the antisolvent bath one or more times during the quench. In other embodiments, the substrate 306 remains stationary in the antisolvent bath during the quench.

[0111] In other embodiments, the post-deposition treatment is an antisolvent spray quench, in which the sprayed film undergoes a similar spraying process as disclosed herein and the perovskite ink 102 is replaced with an antisolvent to extract the remaining solvent. This post-deposition treatment is a good choice if medium-sized grains (e.g., between about 0.2 μm and about 2 μm) are desired for the perovskite film 302. Since this treatment can only partially extract the solvent from the sprayed film, a subsequent post-deposition treatment is typically required. The antisolvent can be ethanol, isopropyl alcohol, butanol, ethyl acetate, methyl acetate, chloroform, chlorobenzene, butyl acetate, 1,2-dichlorobenzene, anisole, trifluorotoluene, ethyl ether, m-xylene, toluene, mesitylene, any combination thereof, or any other suitable antisolvent. To quench the sprayed film, the antisolvent typically has a dipole moment between about 0.1 D and about 3.5 D, such as a dipole moment between about 0.5 D and about 1.2 D for a slow solvent extraction rate, which generally produces a larger and more non-uniform grain (gain) size of the perovskite film 302, or a dipole moment between about 1.5 D and about 3 D for a fast solvent extraction rate, which generally produces a smaller and more uniform grain size of the perovskite film 302.

[0112] In some embodiments, the antisolvent liquid is temperature controlled between about -20°C and about 150°C, for example, between about -10°C and about 10°C, to slow the solvent extraction rate, which generally results in larger and more non-uniform grain sizes of the perovskite film 302, or between about 30°C and 80°C to accelerate the solvent extraction rate, which generally results in smaller and more uniform grain sizes of the perovskite film 302. In other embodiments, the antisolvent liquid is not temperature controlled.

[0113] The optimal anti-solvent composition and temperature may depend at least in part on the type of one or more solvents used for the perovskite ink 102, the amount of solvent remaining after spraying, the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, the one or more subsequent treatments to follow, the desired grain size of the perovskite film 302, the desired morphology of the perovskite film 302, and the desired optoelectronic properties of the perovskite film 302.

[0114] In certain embodiments, by using Figure 1 In another embodiment, the antisolvent spray quenching is performed inside the low pressure chamber 300 by using the spraying arrangement 100 disclosed in the invention and spraying the antisolvent instead of the perovskite ink 102. Figure 1 , and adding a second set of liquid delivery system 108, carrier gas 110, atomizer 112, high pressure chamber 200, and nozzle 202 in series with the first original set to spray the antisolvent through the second set, and completing the antisolvent spray quenching inside the low pressure chamber 300. In this case, the substrate 306 is translated under the first nozzle 202 to be sprayed with the perovskite ink 102, and then continues to translate inline under the second nozzle 202 to be sprayed with the antisolvent. In other embodiments, the antisolvent spray quenching is completed inside the low pressure chamber 300 by adding any suitable liquid spraying device in series with the high pressure chamber 200 and nozzle 202 to spray the antisolvent after the perovskite ink 102. In this case, the substrate 306 is translated under the nozzle 202 to be sprayed with the perovskite ink 102, and then continues to translate inline under the new spraying device to be quenched with the antisolvent. In other embodiments, the antisolvent spray quench is performed inside another enclosure using any suitable liquid spraying equipment under vacuum, in ambient atmosphere, or in any other suitable environment. In some embodiments, the substrate 306 translates in one direction or back and forth beneath the antisolvent outlet during the quench. In other embodiments, the substrate 306 is stationary beneath the antisolvent outlet during the quench.

[0115] In other embodiments, the post-deposition treatment is any combination of the foregoing post-deposition treatments, or any other suitable post-deposition treatment, to nucleate and grow perovskite crystals into the perovskite film 302. The optimal post-deposition treatment may depend, at least in part, on the type of solvent(s) used for the perovskite ink 102, the amount of solvent remaining after spraying, the concentration of the perovskite ink 102, the chemical composition of the perovskite ink 102, whether subsequent treatments will follow, the desired grain size of the perovskite film 302, the desired morphology of the perovskite film 302, and the desired optoelectronic properties of the perovskite film 302.

[0116] Figure 2 is a schematic diagram of a spray coating setup 100. The spray coating setup 100 includes perovskite ink A 104, perovskite ink B 106, two liquid delivery systems 108, a carrier gas 110, an atomizer 112, a high pressure chamber 200, a nozzle 202, a low pressure chamber 300, a perovskite film 302, a substrate 306, a substrate translation system 308, and a vacuum pump valve 310. The liquid delivery system 108, the carrier gas 110, the atomizer 112, the high pressure chamber 200, the nozzle 202, the low pressure chamber 300, the perovskite film 302, the substrate 306, the substrate translation system 308, and the vacuum pump valve 310 can be connected to Figure 1 The same as disclosed in or they may be different.

[0117] From Figure 2 The perovskite ink A 104 and the perovskite ink B 106 are configured as a mixture that is converted into the perovskite film 302 after they are sprayed onto the substrate 306 simultaneously or sequentially, followed by post-deposition processing if necessary. In the simultaneous spraying process, the perovskite ink A 104 and the perovskite ink B 106 are sprayed simultaneously so that the two inks mix before the atomizer 112, inside the atomizer 112, or before the nozzle 202. However, in the sequential spraying process, the perovskite ink A 104 is sprayed first, and after completion, the perovskite ink B 106 is sprayed afterwards.

[0118] In some embodiments, Figure 1 The solute of the perovskite ink 102 disclosed in

[0045] can be separated into two or more inks; in this case, in some embodiments, perovskite ink A 104 and perovskite ink B 106 have the same solute and solvent. In other embodiments, perovskite ink A 104 and perovskite ink B 106 have the same solute but different solvents. In other embodiments, perovskite ink A 104 and perovskite ink B 106 have the same solvent but different solutes. In other embodiments, perovskite ink A 104 and perovskite ink B 106 have different solutes and different solvents.

[0119] The solute may include a perovskite precursor such as methylammonium iodide, methylammonium bromide, formamidine iodide, formamidine bromide, cesium iodide, lead (II) iodide, lead (II) bromide, rubidium iodide, tin iodide, germanium iodide, any combination thereof, or any other suitable perovskite precursor. To improve the quality of the perovskite film 302, a solute additive such as phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, carbohydrazide, any combination thereof, or any other suitable additive may be added to perovskite ink A 104 and / or perovskite ink B 106. To dissolve the solute, a polar aprotic solvent is typically used, such as dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol, acetonitrile, any combination thereof, or any other suitable solvent.

[0120] In other embodiments, perovskite ink A 104 is replaced with perovskite ink 102, and perovskite ink B 106 is replaced with an antisolvent selected from ethanol, isopropyl alcohol, butanol, ethyl acetate, methyl acetate, chloroform, chlorobenzene, butyl acetate, 1,2-dichlorobenzene, anisole, trifluorotoluene, ethyl ether, m-xylene, toluene, mesitylene, any combination thereof, or any other suitable antisolvent. In other embodiments, perovskite ink A 104 is replaced with perovskite ink 102, and perovskite ink B 106, along with its liquid delivery system 108, is removed and replaced with a second carrier gas fluidically connected to the high-pressure chamber 200. In other embodiments, perovskite ink A 104 or perovskite ink B 106 is replaced with perovskite ink 102, and the other ink is replaced with any other suitable liquid or any other suitable gas (e.g., a gas flowing directly into the high-pressure chamber 200) to obtain the perovskite film 302.

[0121] In some embodiments, the type of equipment used in the liquid delivery system 108 and its flow rate are the same for perovskite ink A 104 and perovskite ink B 106. In other embodiments, the type of equipment used in the liquid delivery system 108 is the same for perovskite ink A 104 and perovskite ink B 106, but their flow rates are different. In other embodiments, the type of equipment used in the liquid delivery system 108 is different for perovskite ink A 104 and perovskite ink B 106, but their flow rates are the same. In other embodiments, the type of equipment used in the liquid delivery system 108 and its flow rate are different for perovskite ink A 104 and perovskite ink B 106.

[0122] In some embodiments, both perovskite ink A 104 and perovskite ink B 106 are delivered to an atomizer 112. In other embodiments, perovskite ink A 104 is delivered to a different atomizer than perovskite ink B 106; in this case, the type of equipment used for the atomizer 112, the gas used for the carrier gas 110, and the flow rate for the carrier gas 110 can be the same for perovskite ink A 104 and perovskite ink B 106, or they can be different.

[0123] In other embodiments, any other combination of the foregoing arrangements between perovskite ink A 104 , perovskite ink B 106 , liquid delivery system 108 , atomizer 112 , and carrier gas 110 is acceptable, or any other suitable arrangement.

[0124] Figure 3 Schematic diagram of a spray coating setup 100. The spray coating setup 100 includes perovskite ink A 104, perovskite ink B 106, two liquid delivery systems 108, two carrier gases 110, two atomizers 112, two high pressure chambers 200, two nozzles 202, a low pressure chamber 300, a precursor layer 304, a perovskite film 302, a substrate 306, a substrate translation system 308, and a vacuum pump valve 310. The perovskite ink A 104 and the perovskite ink B 106 are Figure 2 The liquid delivery system 108, carrier gas 110, atomizer 112, low pressure chamber 300, substrate 306, substrate translation system 308 and vacuum pump valve 310 can be the same as those disclosed in FIG. Figure 1 The same as disclosed in, or they may be different.

[0125] From Figure 3 The perovskite ink A 104 and the perovskite ink B 106 are configured as a mixture that is converted into a perovskite film 302 after they are sequentially sprayed onto a substrate 306, followed by subsequent post-deposition processing if necessary. Figure 2 Unlike the sequential spraying process disclosed in (i.e., where the substrate 306 must be translated backward to spray the perovskite ink B 106 because both inks share the same nozzle 202), in Figure 3In the embodiment of the present invention, after spraying perovskite ink A 104, substrate 306 can continue to translate forward under second nozzle 202 to spray perovskite ink B 106. This inline sequential process can form perovskite film 302 at a higher throughput when two or more different perovskite inks are used, and can form thicker perovskite film 302 without reducing throughput when two or more of the same inks are used. In this case, precursor layer 304 is configured as a dry layer or a wet layer (e.g., after spraying perovskite ink A 104), which can be converted into perovskite film 302 after one or more layers of the same or different chemical composition are sprayed on top of it. In this setup, perovskite ink B 106 typically has its own liquid delivery system 108, carrier gas 110, atomizer 112, high-pressure chamber 200, and nozzle 202.

[0126] In some embodiments, Figure 1 The solute of the perovskite ink 102 disclosed in

[0045] can be separated into two or more inks. In some embodiments, perovskite ink A 104 and perovskite ink B 106 have the same solute and solvent. In other embodiments, perovskite ink A 104 and perovskite ink B 106 have the same solute but different solvents. In other embodiments, perovskite ink A 104 and perovskite ink B 106 have the same solvent but different solutes. In other embodiments, perovskite ink A 104 and perovskite ink B 106 have different solutes and different solvents.

[0127] The solute typically includes a perovskite precursor such as methylammonium iodide, methylammonium bromide, formamidine iodide, formamidine bromide, cesium iodide, lead (II) iodide, lead (II) bromide, rubidium iodide, tin iodide, germanium iodide, any combination thereof, or any other suitable perovskite precursor. To improve the quality of the perovskite film 302, solute additives such as phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, carbohydrazide, any combination thereof, or any other suitable additive may be added to perovskite ink A 104 and / or perovskite ink B 106. To dissolve the solute, a polar aprotic solvent is typically used, such as dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol, acetonitrile, any combination thereof, or any other suitable solvent.

[0128] In other embodiments, perovskite ink A 104 is replaced by perovskite ink 102, and perovskite ink B 106 is replaced by an antisolvent selected from ethanol, isopropyl alcohol, butanol, ethyl acetate, methyl acetate, chloroform, chlorobenzene, butyl acetate, 1,2-dichlorobenzene, anisole, trifluorotoluene, ethyl ether, m-xylene, toluene, mesitylene, any combination thereof, or any other suitable antisolvent. In other embodiments, perovskite ink A 104 is replaced by perovskite ink 102, and perovskite ink B 106, its liquid delivery system 108, and its atomizer 112 are removed. In this case, the carrier gas 110 and high-pressure chamber 200, which would otherwise be associated with perovskite ink B 106, are coupled (e.g., directly) to the spray gas rather than the perovskite ink. In other embodiments, perovskite ink A 104 or perovskite ink B 106 is replaced by perovskite ink 102 , and the additional ink is replaced by any other suitable liquid or any other suitable gas (ie, the gas is flowed directly into its high pressure chamber 200 ) to obtain perovskite film 302 .

[0129] In some embodiments, the type of equipment used in the liquid delivery system 108 and its flow rate are the same for perovskite ink A 104 and perovskite ink B 106. In other embodiments, the type of equipment used in the liquid delivery system 108 is the same for perovskite ink A 104 and perovskite ink B 106, but their flow rates are different. In other embodiments, the type of equipment used in the liquid delivery system 108 is different for perovskite ink A 104 and perovskite ink B 106, but their flow rates are the same. In other embodiments, the type of equipment used in the liquid delivery system 108 and its flow rate are different for perovskite ink A 104 and perovskite ink B 106.

[0130] In some embodiments, the gas type and flow rate for the carrier gas 110 are the same for perovskite ink A 104 and perovskite ink B 106. In other embodiments, the gas type for the carrier gas 110 is the same for perovskite ink A 104 and perovskite ink B 106, but their flow rates are different. In other embodiments, the gas type for the carrier gas 110 is different for perovskite ink A 104 and perovskite ink B 106, but their flow rates are the same. In other embodiments, the gas type and flow rate for the carrier gas 110 are different for perovskite ink A 104 compared to perovskite ink B 106.

[0131] In some embodiments, the type of equipment used for the atomizer 112 is the same for perovskite ink A 104 and perovskite ink B 106. In other embodiments, the type of equipment used for the atomizer 112 is different for perovskite ink A 104 and perovskite ink B 106.

[0132] In some embodiments, the material, shape, and / or size of the high pressure chamber 200 is the same for both perovskite ink A 104 and perovskite ink B 106. In other embodiments, the material, shape, and / or size of the high pressure chamber 200 is different for perovskite ink A 104 compared to perovskite ink B 106.

[0133] In some embodiments, the material, shape, and / or size of the nozzle 202 are the same for perovskite ink A 104 and perovskite ink B 106. In other embodiments, the material, shape, and / or size of the nozzle 202 are different for perovskite ink A 104 and perovskite ink B 106.

[0134] In other embodiments, any other combination of the arrangements described herein between perovskite ink A 104 , perovskite ink B 106 , liquid delivery system 108 , atomizer 112 , carrier gas 110 , high pressure chamber 200 , and nozzle 202 is acceptable, or any other suitable arrangement.

[0135] for Figures 1 to 3 In the spray coating arrangement 100 disclosed in , in some embodiments, one or more components are open to the ambient atmosphere. In other embodiments, no components are open to the ambient atmosphere, and the spray coating arrangement 100 is completely under low vacuum.

[0136] for Figures 1 to 3 The spraying apparatus 100 disclosed in the foregoing claims may include additional components for improving and / or better controlling the spraying process. Additional components include liquid filters, droplet filters, gas heaters, liquid heaters, silicon heaters, mass flow controllers, mass flow meters, liquid flow controllers, liquid flow meters, pressure gauges, diffusion dryers, any combination thereof, or any other suitable components.

[0137] The following two non-limiting examples of perovskite films were prepared using the spray coating setup and method described in this disclosure. Figure 1The spraying setup 100 disclosed in the claims, the liquid delivery system 108 and the atomizer 112 are collectively a collision nebulizer, the carrier gas 110 is nitrogen, the high-pressure chamber 200 is a hollow aluminum cylinder having a diameter of about 2.5 inches and a length of about 12 inches, the nozzle 202 is made of aluminum with a slit opening having a length of about 19 mm, a width of about 1.2 mm, and a depth of about 25 mm, the low-pressure chamber 300 is a hollow aluminum sphere having an inner diameter of about 7 inches, the substrate 306 is polished soda-lime glass having a width and length of about 25 mm and a thickness of about 1.1 mm, the distance between the nozzle 202 and the substrate 306 is about 3 mm, the substrate translation system 308 is made of a platform that fixes the substrate 306, a lead screw, and a linear stepper motor, and the vacuum pump valve 310 is a manually actuated gate valve.

[0138] In the first embodiment, the perovskite ink 102 is a solution with a concentration of about 1.2 M. It has Cs 0.05 FA 0.81 MA 0.14 Pb 0.95 (I 0.86 Br 0.14 )3 stoichiometric solute composition, wherein the solute is dissolved in a dimethyl sulfoxide to dimethylformamide solvent ratio of 1 to 4. The amount of ink used is about 3.5 ml. The atomizer 112 is a collision sprayer, which is also a reservoir for the perovskite ink 102. The carrier gas 110 has a flow rate of about 33 SLM, which enters the atomizer 112 to produce droplet sizes between about 1 μm and about 10 μm. Those droplets are transported from the atomizer 112 to the high pressure chamber 200 by the carrier gas 110, which is maintained at a pressure of about 200 Torr. The droplets then begin to accelerate through the nozzle 202 and enter the low pressure chamber 300, which is maintained at a pressure of about 150 Torr. When the substrate 306 translates under the nozzle 202 at a speed of about 0.45 cm / s, a film begins to form on top of the substrate 306. Substrate 306 is composed of polished soda-lime glass with a 30 nm thick layer of poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] on top of the nozzle-facing side. Once substrate 306 passes through nozzle 202 once, carrier gas 110 is turned off, both chambers are vented, and substrate 306 is removed. The sprayed film is wet, so it is immediately quenched in a diethyl ether antisolvent bath for about 15 seconds to partially extract the solvent and allow perovskite crystals to nucleate. Substrate 306 is then annealed on a hot plate in ambient atmosphere at about 100° C. for about 30 minutes to evaporate the remaining solvent and grow perovskite crystals. Once annealing is complete, an 800 nm thick perovskite film 302 is formed.

[0139] In a second embodiment, the perovskite ink 102 is a colloid with a concentration of approximately 0.09 mg / ml. The colloidal particles are quantum dots with a stoichiometric composition of CsPbI3. The quantum dots are suspended in hexane and have a diameter between approximately 5 nm and approximately 20 nm. The ink is first filtered through a 0.2 μm PTFE filter, and the amount used is approximately 150 mL. The atomizer 112 is a collision atomizer, which also serves as a reservoir for the perovskite ink 102. A carrier gas 110 having a flow rate of approximately 5 SLM enters the atomizer 112 to produce droplet sizes between approximately 1 μm and approximately 10 μm. The droplets are then transported from the atomizer 112 by the carrier gas 110 to the high-pressure chamber 200, which is maintained at a pressure of approximately 50 Torr. The droplets then begin to accelerate through the nozzle 202 and into the low-pressure chamber 300, which is maintained at a pressure of approximately 10 Torr. As substrate 306 translated beneath nozzle 202 at a speed of approximately 0.22 cm / s, a film began to form on top of substrate 306. Substrate 306 consisted of polished soda-lime glass with a 100 nm thick layer of titanium dioxide on top of the side facing the nozzle. After approximately two minutes of translating substrate 306 back and forth beneath nozzle 202, carrier gas 110 was turned off, both chambers were vented, and substrate 306 was removed. The sprayed film was dry, requiring no post-deposition treatment, and formed a 600 nm thick perovskite film 302.

[0140] Although this disclosure contains many specific details, they should not be interpreted as limitations on the scope of the subject matter or the scope of what is claimed, but rather as descriptions of features related to particular embodiments. Features described in the disclosed embodiments can be combined to derive multiple other embodiments or combinations of other component subsets. Similarly, features described in the context of embodiments that may not be specific to any disclosed embodiment can be combined to derive multiple other embodiments or combinations of other component subsets.

[0141] Specific embodiments of the subject matter have been described. Other embodiments, modifications, and permutations of the described embodiments are within the scope of the appended claims and will be apparent to those skilled in the art. Although operations may be depicted in a particular order in the drawings or claims, this should not be construed as requiring that the operations be performed in the particular order shown, or in sequential order, or that all illustrated operations (some operations may be deemed optional) be performed, in order to achieve desired results.

[0142] Therefore, the exemplary embodiments described above do not define or constrain the present disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of the present disclosure.

Claims

1. A method for forming a perovskite film on a substrate, the method comprising: atomizing a perovskite precursor composition to produce perovskite precursor droplets, wherein the perovskite precursor composition comprises one or more perovskite precursors; accelerating the perovskite precursor droplet toward the substrate at subatmospheric pressure; collecting the perovskite precursor droplets on the substrate to produce a perovskite precursor layer on the substrate; and A perovskite film is formed on the substrate from the perovskite precursor layer on the substrate, wherein the perovskite film has a crystal structure ABX3, wherein: A represents one or more organic cations, one or more inorganic cations, or one or more of both, B represents one or more metal cations, and X represents one or more halogen anions. 2 . The method of claim 1 , wherein the perovskite precursor composition further comprises a solvent. 3 . The method of claim 2 , further comprising removing the solvent from the perovskite precursor droplets before or after collecting the perovskite precursor droplets on the substrate.

4. The method of claim 3, wherein removing the solvent from the perovskite precursor droplets after collecting the perovskite precursor droplets on the substrate comprises annealing the perovskite precursor layer, exposing the perovskite precursor layer to subatmospheric pressure, immersing or spraying the perovskite precursor layer with an antisolvent, or flowing a gas on top of the precursor layer. 5 . The method of claim 3 , wherein removing the solvent from the perovskite precursor droplets after collecting the perovskite precursor droplets on the substrate comprises heating the substrate.

6. The method of claim 2, wherein the one or more perovskite precursors comprise one or more of methylammonium iodide, methylammonium bromide, methylammonium chloride, formamidine iodide, formamidine bromide, formamidine chloride, cesium iodide, cesium bromide, cesium chloride, lead (II) iodide, lead (II) bromide, lead (II) chloride, rubidium iodide, rubidium bromide, rubidium chloride, tin iodide, tin bromide, tin chloride, germanium iodide, germanium bromide, and germanium chloride.

7. The method of claim 6, wherein the perovskite precursor composition further comprises one or more of phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, (benzylamine) trifluoroboron, tetradecyldimethyl (3-sulfopropyl) ammonium hydroxide inner salt, and carbohydrazide.

8. The method of claim 2, wherein the solvent is a polar aprotic solvent.

9. The method according to claim 8, wherein the solvent comprises one or more of dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol and acetonitrile.

10. The method of claim 2, wherein the perovskite precursor composition is a colloid.

11. The method of claim 10, wherein the one or more perovskite precursors comprise one or more of methylammonium lead iodide, methylammonium tin iodide, methylammonium lead bromide, methylammonium tin bromide, methylammonium lead chloride, methylammonium tin chloride, formamidine lead iodide, formamidine tin iodide, formamidine lead bromide, formamidine tin bromide, formamidine lead chloride, formamidine tin chloride, cesium lead iodide, cesium tin iodide, cesium tin bromide, cesium tin bromide, cesium lead chloride, and cesium tin chloride.

12. The method of claim 11, wherein the solvent is a non-polar solvent.

13. The method of claim 12, wherein the solvent comprises one or more of hexane, octane, pentane, cyclohexane, benzene, and toluene.

14. The method of claim 1 , wherein accelerating the perovskite precursor droplets toward the substrate comprises: transporting the perovskite precursor droplets together with a carrier gas into a first vacuum chamber; and The perovskite precursor droplet is expanded through a nozzle into a second vacuum chamber, wherein the pressure in the first vacuum chamber exceeds the pressure in the second vacuum chamber.

15. The method of claim 14, wherein the pressure in the first vacuum chamber and the second vacuum chamber is in a range between about 0.001 Torr and about 1 Torr, between about 1 Torr and about 100 Torr, between about 100 Torr and about 300 Torr, or between about 300 Torr and about 760 Torr.

16. The method of claim 15, wherein collecting the perovskite precursor droplets on the substrate comprises translating the substrate relative to the nozzle.

17. The method of claim 1, wherein the perovskite film is a continuous coating on the substrate.

18. The method of claim 1, wherein the perovskite film is a conformal coating on the substrate.

19. The method of claim 1, wherein the perovskite precursor droplets have a diameter between about 1 μm and about 10 μm, between about 0.002 μm and about 0.15 μm, between about 0.1 μm and about 8 μm, or between about 5 μm and about 80 μm.

20. The method of claim 1, wherein the perovskite film comprises perovskite grains having a size between about 0.05 μm and about 0.2 μm, between about 0.2 μm and about 2 μm, or between about 2 μm and about 100 μm.

21. A coated substrate comprising: substrate; and a perovskite precursor composition on the substrate, wherein the perovskite precursor composition comprises a solvent and one or more perovskite precursors, and removing the solvent from the perovskite precursor composition produces a perovskite film on the substrate.

22. The coated substrate of claim 21, wherein the one or more perovskite precursors comprise one or more of methylammonium iodide, methylammonium bromide, methylammonium chloride, formamidine iodide, formamidine bromide, formamidine chloride, cesium iodide, cesium bromide, cesium chloride, lead (II) iodide, lead (II) bromide, lead (II) chloride, rubidium iodide, rubidium bromide, rubidium chloride, tin iodide, tin bromide, tin chloride, germanium iodide, germanium bromide, and germanium chloride.

23. The coated substrate of claim 22, wherein the perovskite precursor composition further comprises one or more of phenethylammonium chloride, phenethylammonium iodide, n-octylammonium iodide, n-octylammonium bromide, l-α-phosphatidylcholine, trimethylphenylammonium tribromide, (benzylamine) trifluoroboron, tetradecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt, and carbohydrazide.

24. The coated substrate of claim 21, wherein the solvent is a polar aprotic solvent.

25. The coated substrate of claim 24, wherein the solvent comprises one or more of dimethyl sulfoxide, dimethylformamide, gamma-butyrolactone, N-methyl-2-pyrrolidone, dimethylacetamide, 2-methoxyethanol, and acetonitrile.

26. The coated substrate of claim 21, wherein the one or more perovskite precursors comprise one or more of methylammonium lead iodide, methylammonium tin iodide, methylammonium lead bromide, methylammonium tin bromide, methylammonium lead chloride, methylammonium tin chloride, formamidine lead iodide, formamidine tin iodide, formamidine lead bromide, formamidine tin bromide, formamidine lead chloride, formamidine tin chloride, cesium lead iodide, cesium tin iodide, cesium tin bromide, cesium tin bromide, cesium lead chloride, and cesium tin chloride.

27. The coated substrate of claim 26, wherein the solvent is a non-polar solvent.

28. The coated substrate of claim 27, wherein the solvent comprises one or more of hexane, octane, pentane, cyclohexane, benzene, and toluene.

29. Liquid deposition system, comprising: liquid delivery systems; a nebulizer in fluid communication with the liquid delivery system; a first chamber in fluid communication with the atomizer; Second chamber; a vacuum pump in fluid communication with the second chamber; a nozzle, wherein the first chamber and the second chamber are in fluid communication through the nozzle; and A substrate translation system is configured to translate a substrate relative to the nozzle such that atomized droplets accelerated from the first chamber to the second chamber through the nozzle form a layer on the substrate.

30. The liquid deposition system of claim 29, further comprising: additional fluid delivery systems; an additional nebulizer in fluid communication with the additional liquid delivery system; a third chamber in fluid communication with the additional atomizer; and an additional nozzle, wherein the third chamber and the second chamber are in fluid communication through the nozzle, wherein the substrate translation system is configured to translate the substrate relative to the additional nozzle such that atomized droplets accelerated from the third chamber to the second chamber through the nozzle form a layer on the substrate.

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