High‐Efficiency Precipitate Recycling Strategy Paves the Way for Efficient Sb ₂ S ₃ Solar Cells Fabricated by CBD Method

Sb 2 S 3 solar cells have emerged as a promising candidate for next‐generation photovoltaics. However, the undesirable crystallization of the absorber layer largely hindered the performance of Sb 2 S 3 solar cells. Herein, an innovative precipitate recycling (PR) strategy is proposed to regulate the deposition of Sb 2 S 3 thin films and the subsequent device performance. As a result, this PR strategy enabled high‐ efficiency recycling of raw materials in the traditional CBD method. More importantly, the NH 3 ‐EG solution of Sb 2 S 3 precipitates can effectively regulate the morphology of the precursor film, facilitating the crystallization of Sb 2 S 3 film by promoting thermal diffusion and elemental migration during the post‐annealing process. Consequently, the PR strategy significantly enhanced film crystallinity and [ hk 1] orientation, optimized the CBO of CdS/Sb 2 S 3 interface to −0.17 eV, reduced the back barrier by 35%, and defect concentration by nearly one order of magnitude (converting V S2 donor defect to S Sb2 acceptor defect). Finally, benefiting from the optimized J SC and FF, the power conversion efficiency (PCE) of Sb 2 S 3 solar cells was increased from 4.26% to 5.15%, achieving the highest efficiency for Sb 2 S 3 solar cells based on the CBD‐AT system. These results shed new light on fabricating efficient Antimony‐based solar cells by the CBD method without suffering from severe raw material waste.