| 초록 |
Cu2ZnSn(S,Se4)(CZTSSe) based solar cells are evaluated to have the potential to replace conventional CIGS and CdTe based solar cells because these solar cells consist of earth-abundant and non-toxic elements. However CZTSSe solar cells have low efficiency compared to CIGS solar cells and CdTe solar cells, thus have difficulty in commercialization. The one of the reason is high open-circuit voltage (Voc) deficit due to defects and surface recombination at the interface between absorber layer and buffer layer. Therfore it is very important to improve the interface quality between absorber layer and buffer layer. In this work, to improve the interface quality, the characterization of the buffer layer were adjusted. The properties of CdS vary different thin film thickness. If CdS thickness is thick, the amount of light reaching the absorber layer is limited, resulting in photon loss. If CdS thickness is thin, it is difficult to uniformly cover absorption layer, so it does not function well as a buffer layer. Thus CdS thickness was optimized by controlling the CBD process time and temperature. UV, TEM, and EQE analysis were carried out. |
