Simulation of the Sb2Se3 solar cell with a hole transport layer

Abstract

A model of the Sb2Se3 solar cell with a hole transport layer (HTL) has been investigated by solar cell capacitance simulator (SCAPS). The influence of different HTLs on device performance has been firstly analyzed, and CuO has been found to be the best HTL. Then, Sb2Se3 thickness, CuO thickness, the doping concentration of CuO, the hole mobility of CuO, the defect density of Sb2Se3 layer, the defect density at the CdS/Sb2Se3 interface, and the work function of metal electrode on device performance have been systematically studied. The optimum thicknesses of Sb2Se3 and CuO are 300 nm and 20 nm, respectively. To achieve ideal performance, the doping concentration of CuO should be more than 1019 cm−3, and its hole mobility should be over 1 cm2V−1 s−1. The defect densities in the Sb2Se3 layer and at the CdS/ Sb2Se3 interface play a critical role on device performance, both of which should be as low as 1013 cm−3 and 1014 cm−2, respectively. In addition, the work function of the metal electrode should be more than 4.8 eV to avoid formation of Schottky junction at the metal electrode interface. After optimization, a best efficiency of 23.18% can be achieved. Our simulation results provide valuable information to further improve the efficiency of Sb2Se3 solar cells in practice.