Modeling the current-voltage characteristics of Sb2Se3 thin film solar cells through Sah-Noyce-Shockley recombination model

Abstract

This study investigates the impact of various material parameters, such as film resistivity, the thickness of the absorber layer, uncompensated acceptor density, and carrier lifetime, on the carrier transport and device characteristics of emerging CdS/Sb2Se3 thin-film solar cells. The modeling approach is based on the rigorous Sah-Noyce-Shockley recombination model at the PN-junction, which is based on drift and diffusion collection efficiencies for total current-density calculations. The current-density and voltage have been optimized against the Sb2Se3 thickness and the depletion width at the CdS/Sb2Se3 junction. It has been determined that the lower efficiency of the cell is primarily due to the relatively short electron lifetime and the uncompensated acceptor density, which can widen or narrow the depletion width. The resistivity of the Sb2Se3 film can effectively control the voltage of the cell, however, the carrier lifetime can control this impact even to a higher extent. Therefore, the carrier lifetime and uncompensated acceptor densities are the two interdependent parameters that significantly control the current, voltage, and efficiency of the Sb2Se3 solar cells. This research provides valuable insights for the design and optimization of Sb2Se3 thin-film solar cells shedding light on carrier transport and charge collection mechanism in these emerging materials.