Electrodeposited CuInS2 using dodecylbenzene sulphonic acid as a suspending agent for thin film solar cell

Abstract

CulnS2 thin films were electrochemically deposited onto fluoride-doped tin oxide (FTO) substrate in presence of dodecylbenzene sulphonic acid to adjust pH of the solution and as a suspending agent for the sulfur. Cyclic voltammetry and chronoamperometry were carried out to determine the optimum pH. The composition, crystallinity, and optical properties of the compounds synthesized were studied by energy dispersive X-ray (EDX), X-ray diffraction, and UV-Visible spectra. It was found that the increasing of pH shifts the electrodeposited voltage toward more negative and lowers the deposition current. It was concluded that CuInS2 with atomic stoichiometric ratio was prepared at pH equal to 1.5 and 150ml of 0.1M sodium thiosulphate, 5ml of 0.1M indium chloride, and 5ml of 0.1M cupper chloride. The energy gaps were calculated to be 1.95 and 2.2eV for CuInS2 prepared at 1.5 and 2.5 of pH, respectively. It was found that Jsc, V oc, and are 1.02 × 10-4 A/cm2, 0.52V, and 1.3 10 - 2 %, respectively, for FTO/CuInS2/ZnO/FTO heterojunction solar cell. Copyright © 2012 Shaker Ebrahim et al.