Solar Cells Based on CuInS2 Thin Films through Sulfurization of Precursors Prepared by Reactive Sputtering with H 2S Gas

Abstract

CuInS₂ films were prepared using a two-stage process in which Cu–In–S precursors were sputtered in H₂S/Ar with metal targets (Cu and In) and then annealed in H₂S atmosphere. Control of S content in the precursor is essential for fabricating high-quality CuInS₂ films and achieving high-efficiency solar cells. When S/(Cu+In) ratio in the precursor was about 0.3, CuInS₂ films with good crystallinity and smooth surface were obtained, and consequently a CuInS₂ solar cell with an efficiency of 6.3% has been achieved without KCN treatment.