Sequential deposition route to efficient Sb2S3 solar cells

Abstract

We report a facile two-step sequential deposition method to prepare Sb₂S₃ thin films, where antimony acetate and thiourea are utilized as antimony and sulfur sources, respectively. The sequential deposition of two precursor materials followed by swift annealing at mild temperature leads to high-quality Sb₂S₃ films. The detailed reaction mechanism is revealed on the basis of structural and compositional analyses. By optimizing the concentration of thiourea and annealing temperature, uniform and flat Sb₂S₃ thin films are obtained with either sulfur-deficiency or sulfur richness. Finally, a planar heterojunction solar cell based on the as-prepared Sb₂S₃ film delivers a high power conversion efficiency of 5.69%, which is a top value for planar heterojunction Sb₂S₃ solar cells fabricated by a solution approach. This research provides a convenient and low-cost approach for the deposition of Sb₂S₃ films for efficient solar cell applications.