Abstract:CZTSSe is considered to be the most potential light-absorbing material to replace CIGS, but the actual photoelectric conversion efficiency of this kind of cell stagnates at 13.6%. One of the reasons for the low efficiency 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 AZO/i-ZnO/CdS/CZTSSe1/CZTSSe2/Mo was proposed, and the optimal conduction band offset of CdS/CZTSSe1 interface and CZTSSe1/CZTSSe2 interface were determined by changing the S ratio of CZTSSe1 and CZTSSe2, and the effect of thickness of CZTSSe1 on the performance of the cell were studied. The efficiency 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 had better cell performance.