Synergistic Dipole-Defect Engineering via Sulfonic Molecular Bridge Boosts Voltage in Wide-Bandgap Perovskite and All-Perovskite Tandem Solar Cells
Chen Chen, Yue Zhao, Tianshu Ma, Zhanghao Wu, Yuxiang Guan, Yuhui Liu, Tianci Jia, Yuhang Zhai, Hao Tian, Chuanxiao Xiao, Dewei Zhao, Xiaofeng Li, Changlei Wang
Abstract
Interfacial electric field engineering unlocks high-performance wide-bandgap (WBG) perovskite solar cells (PSCs) for all-perovskite tandem architectures. We introduce 3-sulfopropyl methacrylate potassium salt (SPM), a sulfur-based molecular modulator that creates a dipole-induced built-in electric field at the perovskite/C 60 interface while enabling a synergistic regulation of dual-site defect passivation. The vertically aligned sulfonic (−SO 3 – ) groups in SPM generate an enhanced interfacial dipole, accelerating charge separation. Moreover, the dual Lewis base sites in SPM interact with uncoordinated Pb 2+ via lead–oxygen coordination, healing defects, suppressing ion migration, and inhibiting phase segregation. The optimized 1.77 eV-WBG PSCs demonstrate an efficiency of 19.48% with a V OC of 1.350 V, corresponding to a low V OC -deficit of 0.420 V. Integrating the dipole-optimized top subcell into all-perovskite tandem solar cells achieves a champion efficiency of 28.90% alongside a high V OC of 2.158 V.