Preparation of CuSbS2 Thin Films by Co-Sputtering and Solar Cell Devices with Band Gap-Adjustable n-Type InGaN as a Substitute of ZnO

Abstract

CuSbS2 films were fabricated by co-sputtering with the (Cu + Sb2S3) target at powers of 50 W, 55 W, and 60 W and a Cu target at 2 W under the deposition temperature of 300°C for 2 h, followed by annealing at 350–450°C for 1 h under a Sb2S3 compensation disc to avoid the sulfur deficiency. The (Cu + Sb2S3) cermet target with the composition of Cu:Sb2S3 = 2:1 was formed by hot pressing. The effects of processing conditions on the growth behavior, microstructural characteristics, and electrical properties of CuSbS2 films were investigated. X-ray diffractometry showed that the films prepared by the (Cu + Sb2S3) target at 50 W and 55 W were single phases. The peaks located at 28.4°, 28.7°, and 29.9° were contributed from the (111), (410), and (301) diffraction peaks, respectively. The film prepared with the (Cu + Sb2S3) target at 60 W was Cu rich and had a high electrical conductivity of 180 S cm−1. The 55 W-deposited film was Cu stoichiometric and had low electrical conductivity of 0.05 S cm−1. The 50 W-deposited film with electrical conductivity of 0.24 S cm−1 was good for use as a solar cell device. The solar cell devices made of the p-CuSbS2/n-ZnO system had an efficiency of 0.16%, while it was 0.76% for the p-CuSbS2/n-In0.3Ga0.7N system with the InGaN made by reactive sputtering at 200°C instead of metal–organic chemical vapor deposition above 750°C. This replacement with InGaN for a solar cell device has led to a 4.75-fold increase in efficiency.