A Modeling Study on Utilizing In2S3 as the Buffer Layer of Cu(In,Ga)Se2 Based Solar Cell

Abstract

In Cu(In1 − x,Gax)Se (CIGS)-based solar cells, the cadmium sulfide (CdS) layer is conventionally used as a buffer layer. In the current study, the CdS layer was replaced by the Indium sulfide (In2S3) layer, and the impact of various concentrations of Ga in the CIGS absorber, the band gap of the In2S3 buffer layer, and the band gap of the NayCu1−yIn5S8 interfacial layer on the efficiency of these CIGS solar cells were investigated. The results indicated that in the absence of NayCu1−yIn5S8, the optimal performance was obtained with an Eg−In2S3 value of 3.1 eV and the ratio of Ga/(Ga + In) (GGI) = 1, yielding an efficiency of 21.97%. The formation of the NayCu1−yIn5S8 interfacial layer deteriorated the efficiency of the device, and the highest efficiency of the CIGS solar cells with the interfacial layer was 16.33 %.