Sulphurisation of sequentially electrodeposited Cu-In alloy for the preparation of semiconductor thin films

Abstract

Copper indium disulphide thin films were fabricated by suiphurisation of CuIn alloy prepared by a sequential electrodeposition method. Thin film layers of copper and indium were sequentially electrodeposited on a well-cleaned Ti substrate and on Ti/Cu thin film respectively. The Ti/Cu/In films were then heated at 130�C for 4 hours in air to form Cu-In alloy. Sulphurisation of Cu-In alloy was carried out at 550�C for 30 minutes in 1000/0 HzS gas with a constant flow rate. XRD measurement revealed that the chalcopyrite structure of single phase CulnS2 can be obtained by adopting a proper In concentration in Cu-In alloy. The photoresponse of the CulnS2 films in polysulphide showed the n-type behavior of the films. A p-type ZnSe thin film was deposited on CulnS2, by electrodeposition to produce Ti/CuInS2/ZnSe heterostructure. XRD measurement also revealed that the ZnSe films were amorphous. Spectral response of Ti/CulnS2/ZnSe structure in a PEC cell containing sodium acetate showed the photoactivity of both interfaces n-CulnS2/p-ZnSe and p-ZnSe electrolyte, This study reveals that the thin film solar cell structure Ti/CulnS2/ZnSe/metal may be developed to an efficient solar cell device. The solar cell parameters that we have observed so far are V? =330mV and Isc=2mA/cm2