High-throughput exploration of triple-cation perovskites via ternary compositionally-graded films

A method of synthesizing and characterizing a multiplicity of ternary compositions, the method comprising:

• selecting three components;
• depositing a gradient of a first component along a first axis;
• depositing a gradient of a second component along a second axis which is normal to the first axis, such that the gradient is thickest at a first end and thinnest at a second end;
• and depositing a gradient of a third component along the second axis such that the gradient is thickest at the second end and thinnest at the first end to provide a compositional distribution of the multiplicity of ternary compositions;
• mapping the compositional distribution of each of the multiplicity of ternary compositions;
• and analyzing each of the multiplicity of ternary compositions, thereby synthesizing and characterizing the multiplicity of ternary compositions, wherein the ternary compositions comprise CsxMAyFAzPbI3, and wherein y is between 0.09 and 0.25, z is between 0.89 and 0.75 and x is non-zero and is no greater than 0.1.