Solution‐Processed Compact Sb2S3 Thin Films by a Facile One‐Step Deposition Method for Efficient Solar Cells

Antimony sulfide (Sb 2 S 3 ) is a promising photon‐harvesting material for solar cells. Herein, a facile one‐step deposition method is reported for controllably preparing Sb 2 S 3 nanoparticle films with a preferential [221]‐orientation to a certain extent from a novel precursor solution, formed by dissolving antimony acetate and thiourea in acidified N , N ‐dimethylformamide. With titania (TiO 2 ) nanoparticle films as substrates for in situ‐growing Sb 2 S 3 films, the high‐quality Sb 2 S 3 /TiO 2 planar heterojunction films are obtained for efficient solar cells. The effects of the concentration and [S]/[Sb] molar ratio in the precursor solution on the Sb 2 S 3 film formation and the device performance are investigated. A considerable power conversion efficiency of 5.74% is achieved under AM 1.5G illumination (100 mW cm −2 ), which is the highest efficiency for the solar cells based on solution‐processed Sb 2 S 3 nanoparticle films by one‐step deposition method without further modification. A promising solution‐processing method is provided to prepare high‐quality Sb 2 S 3 films for efficient solar cells and other optoelectronics.