Surfactant Sodium Dodecylbenzenesulphonate Assisted Growth of Large‐Grain Sb₂S₃ Films with Reduced Defect for Highly Efficient Solar Cells

Antimony‐based solar cells have demonstrated significant potential for next‐generation thin film photovoltaics. Among various Sb 2 S 3 preparation methods, the hydrothermal synthesis of Sb 2 S 3 nanocrystal is regarded as one of the most promising approaches for fabricating highly efficient antimony‐based solar cells. However, the hydrothermal process is influenced by numerous factors, leading to Sb 2 S 3 nanocrystals with uneven sizes and high defect state densities. To address these issues and optimize hydrothermal process, we synthesized Sb 2 S 3 crystal by incorporating an anionic surfactant, sodium dodecylbenzenesulphonate (SDBS), into the reaction precursor. By further fine‐tuning the amount of SDBS, uniform and large grain size Sb 2 S 3 crystals with reduced defect state were obtained, while the formation of the nonphotovoltaic active phase of Sb 2 O 3 was effectively suppressed. Consequently, antimony‐based solar cells prepared by SDBS additive yield an impressive power conversion efficiency of 6.77%, accompanied by significantly enhanced charge separation and extraction, an increased depletion width, inhibited nonradiative recombination, and improved long‐term stability.