Remarkable enhancement of the efficiency of Cu(In,Ga)Se2 solar cells by annealing the (In,Ga)2Se3 precursor layer

Thin film solar cells based on chalcopyrite Cu(In, Ga)Se-2 (CIGSe) absorber layers were fabricated successfully using a three-stage co-evaporation process. The effects of annealing the (In, Ga)(2)Se-3 (IGSe) precursor layer on the preferred orientation and morphology of the CIGSe films as well as the performance of the Ag/Ni/(Ga, Al): ZnO/i-ZnO/CdS/CIGSe/Mo/Glass cell were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and illuminated J-V and quantum efficiency measurements. Layer studies indicated that the CIGSe film texture changed from (112) to (220) with increasing annealing time. Cell studies showed that the performance of the solar cell was improved with an abrupt change in the open circuit voltage and a remarkable increase in efficiency from 7.35% to 14.35% according to the annealing time in the range, 0-30 min. (C) 2015 Elsevier B.V. All rights reserved.