Abstract: Described herein are non-stoichiometric perovskite ink solutions, comprising: a first composition of formula FA1-xCsxBX3; a second composition of CsX, FAX, REX3, or REX2; and one or more solvents; wherein x, X, RE, and B are as defined herein. Methods for preparing polycrystalline perovskite films using the non-stoichiometric ink solutions and the use of the films in large-size solar modules are additionally described.

Abstract: In an aspect, a method of forming a photoactive device comprises: providing a perovskite-surfactant solution, said perovskite-surfactant solution comprising a perovskite ink and a surfactant; and coating said perovskite-surfactant solution onto a receiving surface of a substrate thereby forming a layer of said photoactive device; wherein said layer comprises a perovskite material; and wherein an active area of said photoactive device is at least 1 cm2.

Abstract: Described herein are non-stoichiometric perovskite ink solutions, comprising: a first composition of formula FA1-xCsxBX3; a second composition of CsX, FAX, REX3, or REX2; and one or more solvents; wherein x, X, RE, and B are as defined herein. Methods for preparing polycrystalline perovskite films using the non-stoichiometric ink solutions and the use of the films in large-size solar modules are additionally described.

Abstract: Described herein is an ink solution, comprising a composition of formula (I): ABX3(I), wherein A comprises at least one cation selected from the group consisting of methylammonium, tetramethylammonium, formamidinium, cesium, rubidium, potassium, sodium, butylammonium, phenethylammonium, phenylammonium, and guanidinium; B comprises at least one divalent metal; and X is at least one halide; and a mixed solvent system comprising two or more solvents selected from the group consisting of dimethyl sulfoxide, dimethylformamide, ?-butyrolactone, 2-methoxyethanol, and acetonitrile. Methods for producing poly-crystalline perovskite films using the ink solutions described herein and the use of the films in photovoltaic and photoactive applications are additionally described.

Abstract: In an aspect, a method of forming a photoactive device comprises: providing a perovskite-surfactant solution, said perovskite-surfactant solution comprising a perovskite ink and a surfactant; and coating said perovskite-surfactant solution onto a receiving surface of a substrate thereby forming a layer of said photoactive device; wherein said layer comprises a perovskite material; and wherein an active area of said photoactive device is at least 1 cm2.