An Optimization Path for Sb2(S,Se)3 Solar Cells to Achieve an Efficiency Exceeding 20%

Antimony selenosulfide, denoted as Sb-2(S,Se)(3), has garnered attention as an eco-friendly semiconductor candidate for thin-film photovoltaics due to its light-absorbing properties. The power conversion efficiency (PCE) of Sb-2(S,Se)(3) solar cells has recently increased to 10.75%, but significant challenges persist, particularly in the areas of open-circuit voltage (V-oc) losses and fill factor (FF) losses. This study delves into the theoretical relationship between V-oc and FF, revealing that, under conditions of low V-oc and FF, internal resistance has a more pronounced effect on FF compared to non-radiative recombination. To address V-oc and FF losses effectively, a phased optimization strategy was devised and implemented, paving the way for Sb-2(S,Se)(3) solar cells with PCEs exceeding 20%. By optimizing internal resistance, the FF loss was reduced from 10.79% to 2.80%, increasing the PCE to 12.57%. Subsequently, modifying the band level at the interface resulted in an 18.75% increase in V-oc, pushing the PCE above 15%. Furthermore, minimizing interface recombination reduced V-oc loss to 0.45 V and FF loss to 0.96%, enabling the PCE to surpass 20%. Finally, by augmenting the absorber layer thickness to 600 nm, we fully utilized the light absorption potential of Sb-2(S,Se)(3), achieving an unprecedented PCE of 26.77%. This study pinpoints the key factors affecting V-oc and FF losses in Sb-2(S,Se)(3) solar cells and outlines an optimization pathway that markedly improves device efficiency, providing a valuable reference for further development of high-performance photovoltaic applications.