Method of forming a crystalline or polycrystalline layer of an organic-inorganic metal halide perovskite

Abstract

The present invention provides a method of forming a crystalline or polycrystalline layer of an organic-inorganic metal halide perovskite material comprising a three-dimensional crystal structure represented by the formula AMX3, in which A represents an organic cation or a mixture of two or more different cations, at least one of which is an organic cation, M represents a divalent metal cation or a mixture of two or more different divalent metal cations, and X represents halide anions which are the same or different, the method comprising the steps of: (i) forming a first layer on the surface of a substrate, the first layer comprising an organic-inorganic metal halide perovskite material having a planar, layered two-dimensional crystal structure (ii) reacting the first layer with one or more organic halides to form the crystalline or polycrystalline layer comprising an organic-inorganic metal halide perovskite material having the formula AMX3. Also provided is an optoelectronic or photovoltaic device including an active layer comprising an organic-inorganic metal halide perovskite material comprising a three-dimensional crystal structure represented by the formula AMX3, wherein the material is obtainable using the above defined method.

Dependencies are inferred from the claim text.