CHARACTERISTICS OF PULSE ELECTRODEPOSITED AgIn0.5Ga0.5Se2 THIN FILMS

AgIn0.5Ga0.5Se2 thin films were pulse electrodeposited on tin oxide coated glass substrates at different duty cycle in the range of 6 – 50%. The deposition potential was maintained as -0.68V (SCE). Thickness of the films increased from 600 – 800 nm with increase of duty cycle. Single phase chalcopyrite films were obtained. Band gap of the films increased from 1.40 – 1.48 eV with increase of duty cycle. Transmission spectra exhibited interference fringes. Refractive index was evaluated by the envelope method. Photoekectrochemical cells were fabricated using the films deposited at different duty cycle. The as deposited films exhibit very low photoactivity. In order to increase the photo output the films were post heat treated in argon atmosphere at different temperatures in the range of 450 - 525ºC. The photo output was Voc = 0.52 V, Jsc = 11.50 mA cm-2, ff = 0.56, η = 3.50% at 80 mW cm-2. Photoetching increased the output parameters.