Enhancement of the performance of kesterite thin-film solar cells using dual absorber and ZnMgO buffer layers

A new structure of kesterite thin-film solar cells is simulated using SCAPS software. In addition, the structures of CZTS/ZnMgO, CZTSSe/CZTS/CdS and CZTSSe/CZTS/ZnMgO are suggested and scrutinized. In CZTS/ZnMgO structure, the efficiency, open-circuit voltage and short circuit current at the absorber layer thickness of 3 mu m have been improved 35%, 15%, and 15% respectively. Furthermore, the efficiency of the proposed solar cell has been enhanced 60% by adding the CZTSSe absorber layer on the back of the CZTS layer. The optimum buffer layer thickness in the structures of CZTSSe/CZTS/CdS and CZTSSe/CZTS/ZnMgO are 150 nm and 125 nm, respectively. The simulation results show that the basic photovoltaic parameters (V-OC, J(SC), FF and eta) have been decreased by variation of temperature from 300 K to 400 K. The optimal bandgap of the CZTSSe and ZnMgO in the structure of CZTSSe/CZTS/ZnMgO are obtained 0.9eV and 3.48eV, respectively in the ZnMgO optimal thickness of 50 nm. The highest efficiency of the kesterite solar cell with Zn0.81Mg0.19O buffer layer is 17.05%.