Antimony Oxide Enabled Ion‐Dominant Deposition for High‐Efficiency Sb ₂ S ₃ Solar Cells

ABSTRACT To date, the quality of antimony sulfide (Sb 2 S 3 ) absorber severely restrains the performance improvement for this emerging photovoltaic device. Herein, the deposition dynamics of hydrothermally prepared Sb 2 S 3 films is precisely regulated by using an alternative antimony source of antimony trioxide (Sb 2 O 3 ), inducing desirable crystallization features and photoelectric properties for high‐efficient device construction. With the collaboration of ethylenediaminetetraacetic acid disodium salt (EDTA‐2Na) and tartaric acid (H 2 Tar, C 4 H 6 O 6 ), the release rate of Sb 3+ ions can be effectively controlled by the Tar/EDTA‐Sb(OH) 2 dual‐chelates, resulting in ion‐reactive deposition process for Sb 2 S 3 film. Simultaneously, the release rate of S element from sodium thiosulfate (STS) is promoted in the presence of H 2 Tar, causing in situ sulfuration during the crystallization process. Comprehensively, the Sb 2 O 3 ‐derived Sb 2 S 3 film possesses more effective carrier transport kinetics compared with the conventional Sb 2 S 3 film prepared from potassium antimonate (APT). Ultimately, the device has achieved an 8.19% PCE, which is the highest efficiency reported to date for Sb 2 S 3 solar cells derived from Sb 2 O 3 . This work demonstrates the importance of deposition dynamics in modulating film quality to construct high‐efficient Sb 2 S 3 ‐based photovoltaic devices.