Efficient Copper‐Doped Antimony Sulfide Thin‐Film Solar Cells via Coevaporation Method

Sb 2 S 3 being a light‐absorbing material is used for photovoltaic (PV) application due to its superior stability and progressive power conversion efficiency (PCE) benefiting from its low cost, less toxic, earth‐abundant, and facile nature. Due to the difficulty in efficient doping for such 1D structure, the performance of as‐fabricated thin‐film solar cells is limited by high resistivity and hole extraction barrier. Herein, a coevaporation scheme is introduced for copper‐doped Sb 2 S 3 by rapid thermal evaporation (RTE). The Cu‐doped Sb 2 S 3 thin film discloses the enhanced crystallinity with a grain diameter greater than 1 µm and conductivity along with improved carrier concentration. At the same time, the deep valance band obtains a minor upshift, favoring the hole extraction at back contact. Consequently, all the PV parameters are enhanced leading to the PCE boosting from 4.18% to 4.61%. Herein, a facile doping technique is demonstrated to improve its performance without any modification of the present RTE method.