Preparation and characterization of CuInS2 thin films from aqueous solutions by novel photochemical deposition technique

CuInS2 (CIS) thin films were deposited on ITO glass substrate by a two-step process using a simple and low-cost photochemical deposition technique. In the first step InS thin films were deposited from aqueous solution of In-2(SO4)(3) and Na2S2O3 and in the second step CuxS films were deposited on the InS films from CuSO4 and Na2S2O3. The as-deposited films were annealed at 300 degrees C for 30 min. Annealed samples were characterized using Raman spectroscopy, Auger electron spectroscopy, scanning electron micrograph and optical transmission study, etc. It was observed that ternary layers were formed by interdiffusion of Cu and In during the annealing and that composition of the annealed films was determined by the deposition time of the binary layers. By optimizing the condition, nearly stoichiometric CIS was obtained. (C) 2004 Elsevier B.V. All rights reserved.