Impact of loss mechanisms through defects on Sb₂(S_1-xSe_x)₃/CdS solar cells with p-n structure

Antimony sulfide selenide (Sb₂(S_1-xSe_x)₃) material has emerged as a potential candidate for solar cell fabrication. However, up-to-date, efficiencies of about 7% have been widely reported for solar cells based on this absorber material under a p–n junction. Further experimental and theoretical attempts are required to find the main limitations of this type of solar cell. In this work, a theoretical study is presented to evaluate the influence of loss mechanisms on antimony sulfide selenide solar cells. In particular, the effect of bulk recombination, tunneling enhanced recombination and Sb₂(S_1-xSe_x)₃/CdS interface recombination on device parameters is evaluated at different Sb₂(S_1-xSe_x)₃ compositions. Bulk and interface defects were identified as the main loss mechanisms degrading device efficiency, while the effect of electric field in enhancing carrier recombination in the depletion region can be neglected. In addition, it is demonstrated that a further efficiency increase over 14% could be only obtained for an electron lifetime higher than 100 ns and a recombination speed shorter than 1 cm/s at the Sb₂(S_1-xSe_x)₃/CdS interface.