Sb₂S₃ has attracted widespread attention as a photovoltaic absorber material owing to its excellent photoelectric properties. However, the performance of Sb₂S₃-based solar cells is partly limited by its inappropriate band structure, such as deep valence band maximum (VBM) and wide bandgap, which critically lowers hole extraction efficiency and sets a threshold for attainable short-circuit current density (J_sc). Herein, a cationic bismuth-doping is applied to manipulate the energy level of Sb₂S₃ film by a hydrothermal process. As a result, the alloyed (Bi,Sb)₂S₃ delivers a redshift of absorption edge and an upshifted VBM, which are in line with our first-principles calculation. The optimized band structure markedly increases the light-harvesting and hole extraction efficiency. Additionally, the suitable doping of Bi also enhances grain size and preferred [hk1] orientation of absorber layer, consequentially favoring the carrier transport. Finally, this Bi-doping tactic boosts the device efficiency from 3.98 to 5.20% and J_sc from 12.58 to 15.38 mA/cm² compared with pristine Sb₂S₃. This work paves an avenue for cationic-doping strategy in Sb₂S₃ solar cell.

Sb ₂ S ₃因其优异的光电性能而作为光伏吸收材料受到广泛关注。然而，Sb ₂ S ₃基太阳能电池的性能部分受限于其不适当的能带结构，例如深价带最大值（VBM）和宽带隙，这严重降低了空穴提取效率并为可达到的短路设定了阈值电流密度 ( J _sc )。_{在此，阳离子铋掺杂被应用于通过水热工艺控制Sb 2} S ₃薄膜的能级。结果，合金化的 (Bi,Sb) ₂ S ₃提供吸收边缘的红移和上移的 VBM，这与我们的第一性原理计算一致。优化的能带结构显着提高了光捕获和空穴提取效率。此外，Bi 的适当掺杂还提高了吸收层的晶粒尺寸和优选的 [hk1] 取向，从而有利于载流子传输。最后，与原始 Sb ₂ S ₃相比，这种双掺杂策略将器件效率从 3.98% 提高到 5.20%，将J _sc从 12.58 提高到 15.38 mA/cm ²。_{这项工作为 Sb 2} S ₃太阳能电池中的阳离子掺杂策略铺平了道路。