Simulation of the Sb₂Se₃ solar cell with a hole transport layer

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. (paper)