A Photoluminescence Study on CuInS2 Thin Films Prepared by the Sequential Deposition Technique

Abstract

Solar energy conversion to electrical energy using low cost solar cells contributes substantially for a solution to the present global energy crisis. In this respect, various semiconductor materials are being studied for possible applications in low cost solar cell devices. Copper Indium Di Sulphide (CuInS2) is very promising semiconductor material because of its electronic and optical properties, which are suitable for these applications. Low-cost semiconductor material growth techniques normally produce unwanted electronic states in the material producing undesired effects on the solar cell application. In this investigation, CuInS2 thin films prepared by the electrodeposition of Cu films followed by the In deposition were used to prepare Cu-In alloy. Cu-In alloy was suplherized in an H2S chamber to grow CuInS2 films. X-ray diffraction and optical characterizations suggest that the films are of good quality. The photoluminescence study at low temperature produced two peaks at 815nm and 880 nm. This result suggests the band to band transition and the sulfur vacancy transition. Our study reveals that there are no other defect electronic states in the band gap except the S vacancies, confirming the good quality of the material