Abstract:Cu2ZnSn(S,Se)4 (CZTSSe) is considered to be the most potential light-absorbing material to replace CuInGaSe2 (CIGS), but the actual photoelectric conversion efficiency of such cells is much lower than that of CIGS. One of the reasons is the high recombination rate of carriers at the interface. In this paper, in order to reduce the carrier recombination, a new solar cell structure with double absorber layers of Al-doped ZnO (AZO)/intrinsic (i)-ZnO/CdS/ CZTSx1Se1-x1 (CZTSSe1)/CZTSx2Se1-x2 (CZTSSe2)/Mo was proposed, and the optimal conduction band offsets (CBOs) of CdS/CZTSSe1 interface and CZTSSe1/CZTSSe2 interface were determined by changing the S ratio in CZTSSe1 and CZTSSe2, and the effect of thickness of CZTSSe1 on the performance of the cell was studied. The efficiencies of the optimized single and double absorber layers reached 17.97% and 23.4%, respectively. Compared with the single absorber layer structure, the proposed structure with double absorber layers has better cell performance.