Full‐Dimensional Penetration Strategy with Degradable PEAI Enables 8.21% Efficiency in Bulk Heterojunction Sb<sub>2</sub>S<sub>3</sub> Solar Cells
Yang Wang, Dong Yang, Mengqi Jin, Zhiyang Wan, Wenbo Cao, Faisal Naveed, Jiajin Kuang, Chaofan Zheng, Chaoyang Wang, Junwei Chen, Yingying Dong, Mingtai Wang, Chong Chen
Abstract
Abstract Antimony trisulfide (Sb 2 S 3 ) is a promising low‐cost photovoltaic material, but practical Sb 2 S 3 solar cells suffer from multiple defects, anisotropic transport, and interfacial energy‐level mismatches, limiting power conversion efficiency ( η ) to 6%‐7%. Herein, a degradable full‐dimensional penetration passivation strategy using phenethylammonium iodide (PEAI) is proposed to synergistically address these issues. PEAI pretreatment of amorphous Sb 2 S 3 films enables [ hk 1]‐oriented crystallization, full‐dimensional defect passivation (bulk and interfaces), and dual‐interface energy‐level reconstruction via Cd‐I and Sb─I bonding. The PEAI reduces CdS surface energy and preferentially adsorbs on Sb 2 S 3 (211) planes, promoting [ hk 1] orientation and enhancing carrier transport. Moreover, the penetrated PEAI leads to a 3.7‐fold increase in carrier lifetime, verifying effective defect suppression. The resultant bulk heterojunction (BHJ) solar cells achieve a η of 8.21%, which is the highest efficiency of BHJ Sb 2 S 3 solar cells. This work establishes a quadruple‐integrated paradigm (defect passivation, orientation control, energy‐level optimization, and architecture design), providing a universal roadmap for high‐efficiency, sustainable photovoltaics.