Chemically Sprayed p-type CuS Thin Film-Characterization and Feasibility Study on Junction with n-Si for the Development of Solar Cell

Abstract

Metal sulphides have been subjected to extensive research due to their excellent optoelectronic properties. Among them, CuS is a p-type material with a wide band gap in the range of 1.5-2.6 eV, having applications in various fields like sensors, solar cells, photo detectors etc. As an important non-toxic, earth abundant, highly p-doped semiconductor with its metal-like electrical conductivity, CuS has attracted much attention in recent years to fabricate wide range of optical and electrical devices. Different methods have been used for the CuS thin films deposition; among them, Chemical Spray Pyrolysis (CSP) technique is a promising one, because of its simplicity, cost effectiveness and scalability for large area deposition. This paper reports the preparation and characterization of CuS thin films deposited by vacuum free chemical spray pyrolysis. The covellite CuS thin film was grown on glass substrate at 300°C using copper chloride and thiourea as precursors without the use of any complexing agent. Optical and structural characterizations of the thin films were done using, UV-Visible optical absorption, Raman spectra, X ray diffraction, Scanning Electron Microscope. The Hall measurement showed that sample has a p-type conductivity with a hole concentration of $\sim 1.37\times 10^{19}\text{cm}^{-3}$. Further, fabrication and characterization of pCuS/n-cSi heterojunction was also done.