Novel Solution Processing of High‐Efficiency Earth‐Abundant Cu2ZnSn(S,Se)4 Solar Cells

Abstract
A novel solution‐based approach is presented to process earth‐abundant Cu2ZnSn(S,Se)4 absorbers using fully dissolved CZTS precursors in which each of the elemental constituents intermix on a molecular scale. This method enables the low‐temperature processing of chemically clean kesterite films with excellent homogeneity. The high performance of resulting optoelectronic devices represents a chance to extend the impact of CZTS into the next chapter of thin‐film solar cells.