Technique for Achieving Large-Grain Ag2ZnSn(S,Se)4 Thin Films

摘要

Techniques for increasing grain size in AZTSSe absorber materials are provided. In one aspect, a method for forming an absorber film on a substrate includes: contacting the substrate with an Ag source, a Zn source, a Sn source, and an S source and/or an Se source under conditions sufficient to form the absorber film on the substrate having a target composition of: Ag_XZn_YSn(S,Se)_Z, wherein 1.7x2.2, 0.9y1.3, and 3.5z4.5, and including an amount of the Ag source that is from about 10% to about 30% greater than is needed to achieve the target composition; annealing the absorber film; and removing excess Ag from the absorber film. A solar cell and method for fabrication thereof are also provided.