Electrosynthesis and Characterization of a Culns 2 Good Absorber Semiconductor for Thin Film Solar Cells

Thin films of CuInS2 have been prepared by electrodeposition on SnO2/glass substrate from aqueous solutions of InCl3, CuSO4 and Na2S2O3. This semiconductor is one the most promising ternary absorber materials for thin film solar cells. A stoichiometric composition and good crystallinity were obtained by a one step electrodeposition at -1145 mV vs. saturated calomel electrode (SCE). To improve their crystallinity, the samples were annealed under sulfur atmosphere at 450 0 C for 30 minutes. Scanning Electronic Microscopy, Energy Dispersive Spectroscopy and X-Ray diffraction were used to characterize the films. Particles Size distribution, film thickness and normalized composition of the semiconductor, under different conditions, have been estimated. Optical studies, using absorption spectroscopy, gave an absorption coefficient of 10 5 cm -1 and an energy band gap of 1.53 eV, which is in good agreement with the values reported in literature regarding the growth of thin films of this material using other methods.