Characterization of CuInS2 films prepared by atmospheric pressure spray chemical vapor deposition

Copper indium disulfide films were deposited by atmospheric pressure spray chemical vapor deposition (CVD). Films were deposited at 390 °C using [(PPh3)2CuIn(SEt)4] as a single source precursor in an argon atmosphere. The films range in thickness from 0.75 to 1.0 μm and exhibit a crystallographic gradient, with the leading edge having a (220) preferred orientation and the trailing edge having a (112) orientation. Schottky diodes prepared by thermal evaporation of aluminum contacts onto the CuInS2 yielded diodes for films that were annealed at 600 °C. The photoresponse of several films was measured by photoelectrochemical analysis in an aqueous, acidic electrolyte. Prolonged exposure of the films to the electrolyte caused a decreased photoresponse. Complete solar cells were prepared using annealed films and had the (top down) composition of Al/ZnO/CdS/CuInS2/Mo/Glass. The short-circuit current (Isc), open-circuit voltage (Voc), maximum power output (Pmax), current at Pmax (Imax), voltage at Pmax (Vmax), fill factor (FF) and efficiency (η) were 5.25 mA, 304 mV, 0.470 mW, 2.92 mA, 161 mV, 29.4 and 0.68%, respectively, for a 0.5 cm2 cell under simulated AM0 illumination.