High-Efficiency Precipitate Recycling Strategy Paves the Way for Efficient Sb₂S₃ Solar Cells Fabricated by CBD Method

Sb₂S₃ 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 Sb₂S₃ solar cells. Herein, an innovative precipitate recycling (PR) strategy is proposed to regulate the deposition of Sb₂S₃ 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 NH₃-EG solution of Sb₂S₃ precipitates can effectively regulate the morphology of the precursor film, facilitating the crystallization of Sb₂S₃ film by promoting thermal diffusion and elemental migration during the post-annealing process. Consequently, the PR strategy significantly enhanced film crystallinity and [hk1] orientation, optimized the CBO of CdS/Sb₂S₃ 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 Sb₂S₃ solar cells was increased from 4.26% to 5.15%, achieving the highest efficiency for Sb₂S₃ 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.