Performance evaluation of CuSbX₂ (X = S, Se)-based 2 T tandem solar cells towards high efficiency

Tandem solar cells signify a remarkable progression in photovoltaic technology, engineered to exceed the efficiency constraints inherent in single-junction solar cells. This research manifests a theoretical investigation of CuSbX 2 (S, Se)-based two-terminal (2 T) dual heterojunction tandem solar cells. This study used the SCAPS 1D software to assess the effectiveness of the methodically designed tandem device. The band gap of the CuSbS 2 chalcogenide compound is 1.67 eV, and it acts as the absorber layer in the top cell. While the CuSbSe 2 chalcogenide compound, with a band gap of 1.08 eV, performs as an absorber layer in the bottom cell. The short circuit current density (J SC ) of the upper cell aligns with that of the lower cell when the thickness of CuSbSe 2 is taken as 0.77 μm. The optimized CuSbX 2 (S, Se)-based tandem device achieves a substantial open circuit voltage (V OC ) of 2.22 V and a remarkable efficiency of 41.64% at the current matching point. The findings presented herein may facilitate the advancement of extremely efficient tandem solar cells based on chalcogenide compounds.