Solvent‐Assisted Hydrothermal Deposition Approach for Highly‐Efficient Sb2(S,Se)3 Thin‐Film Solar Cells.

Antimony chalcogenides (Sb2(SxSe1−x)3, 0 < x < 1) have recently gained popularity due to their excellent photoelectric properties. As a newcomer to thin‐film solar cells, the quality of the as‐prepared absorb layer remains the most difficult challenge, owing to its distinct crystal structure. Here, a solvent‐assisted hydrothermal deposition (SHD) technique is developed for direct deposition of high‐quality Sb2(S,Se)3 films; it is realized that the addition of ethanol can regulate the reaction kinetics by regulating the concentration of the Sb source during the deposition procedure. Impressively, under such conditions, the deposition rate of the target absorb layer slows dramatically, resulting in more suitable features, such as large grain size, smooth surface, and proper bandgap, which are beneficial for constructing high performance solar devices. More importantly, using this newly developed SHD strategy, the defect (SbS1) density of the prepared films decreases by more than one order of magnitude, which is believed to benefit carrier transport. As a result, Sb2(S,Se)3 solar cells based on the SHD strategy significantly improve fill factor and short‐circuit current density, yielding a high efficiency of 10.75%. This research offers fresh insights into how to make Sb2(S,Se)3 films and solar cells of higher quality. [ABSTRACT FROM AUTHOR]