Sb₂(Se1‐xSx)₃ Thin‐Film Solar Cells Fabricated by Single‐Source Vapor Transport Deposition

The properties of Sb 2 (Se 1‐x S x ) 3 alloy films can be continuously tuned by changing its composition, enabling potentially better device efficiency compared to the Sb 2 S 3 or Sb 2 Se 3 counterparts. Fabrication of Sb 2 (Se 1−x S x ) 3 films with good uniformity and orientation are prerequisites to realize their full potential. Here, pure‐phase and high‐uniformity Sb 2 (Se 1‐x S x ) 3 absorbers are successfully produced via a vapor transport deposition method employing a single evaporation source. Increasing the travelling distance of vapor particles can improve the morphology and crystallinity of Sb 2 (Se 1‐x S x ) 3 films, and as a result, compact Sb 2 (Se 1‐x S x ) 3 films with strong preferential [221] orientation and uniform composition throughout the whole film are obtained. Further, the CdS surface is treated with H 2 O 2 solution and a device with a champion efficiency of 6.30% is obtained, a new efficiency record for Sb 2 (Se 1‐x S x ) 3 based thin‐film solar cells without a hole‐transporting layer.