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.