Abstract
Cu(In,Ga)Se-2 (CIGS) thin films were prepared by directly sputtering Cu(In,Ga)Se-2 quaternary target consisting of Cu:In:Ga:Se =25:17.5:7.5:50 at%. The composition and structure of CIGS layers have been investigated after annealing at 550 degrees C under vacuum and a Se-containing atmosphere. The results show that recrystallization of the CIGS thin film occurs and a chalcopyrite structure with a preferred orientation in the (112) direction was obtained. The CIGS thin film annealed under vacuum exhibits a loss of a portion of Se, while the film annealed under Se-containing atmosphere reveals compensation of Se. Several solar cells with three different absorber thicknesses were fabricated using a soda lime glass/Mo/CIGS/CdS/i-ZnO/ZnO:Al/Al grid stack structure. The highest conversion efficiency of 9.65% with an open circuit voltage of 452.42 mV, short circuit current density of 32.16 mA cm(-2) and fill factor of 66.32% was obtained on a 0.755 cm(2) cell area. (c) 2013 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.