Sb₂S₃ is a promising photovoltaic absorber with appropriate bandgap, excellent light absorption coefficient and great stability. However, the power conversion efficiency (PCE) of Sb₂S₃ planar thin film solar cells is unsatisfactory for further commercial application due to low crystallinity and high resistivity of Sb₂S₃ film. Here, we introduce an additive of 4-Chloro-3-nitrobenzenesulfonyl Chloride (CSCl) to alleviate these problems. The CSCl molecular contains two terminal Cl with lone pair electrons, which have the interaction with Sb atoms. Thus, the Sb₂S₃ film with enhanced crystallization and low trap states has been obtained and the resistivity is also decreased. Furthermore, CSCl additive raises the Fermi level of the Sb₂S₃ film, thereby enhancing the transport of electron from Sb₂S₃ to TiO₂. Consequently, the optimal PCE of Sb₂S₃ solar cells is raised from 4.20% (control device) to 5.84%. Our research demonstrates a novel additive to enhance the photoelectric performance of Sb₂S₃ solar cells.

Sb ₂ S ₃是一种很有前途的光伏吸收体，具有合适的带隙、优异的光吸收系数和良好的稳定性。然而，由于Sb ₂ S ₃薄膜的低结晶度和高电阻率，Sb ₂ S ₃平面薄膜太阳能电池的功率转换效率（PCE）不能满足进一步的商业应用。在这里，我们引入了 4-Chloro-3-nitrobenzosulfonyl Chloride (CSCl) 的添加剂来缓解这些问题。CSCl分子含有两个带有孤对电子的末端Cl，它们与Sb原子发生相互作用。因此，Sb ₂ S ₃获得了具有增强结晶和低陷阱态的薄膜，并且电阻率也降低了。此外，CSCl添加剂提高了Sb ₂ S ₃膜的费米能级，从而增强了电子从Sb ₂ S ₃到TiO ₂的传输。因此，Sb ₂ S ₃太阳能电池的最佳PCE从4.20%（控制装置）提高到5.84%。我们的研究证明了一种新型添加剂可以提高 Sb ₂ S ₃太阳能电池的光电性能。