4‑Trifluorophenylammonium Iodide-Based Dual Interfacial Modification Engineering toward Improved Efficiency and Stability of SnO2‑Based Perovskite Solar Cells

• Published in: ACS applied materials & interfaces 2023-02, Vol.15 (5), p.6777-6787
• Main Authors: Liu, Tao, Guo, Xi, Liu, Yinjiang, Hou, Meichen, Yuan, Yihui, Mai, Xianmin, Fedorovich, Kuzin Victor, Wang, Ning
• Format: Article
• Language: English
• Subjects: Energy, Environmental, and Catalysis Applications
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.2c19549

Passivation engineering has been identified as an effective strategy to eliminate the targeted interfacial defects for improving the efficiency and stability of perovskite solar cells (PSCs). Herein, 4-trifluorophenylammonium iodide (CF3PhAI) is presented as a multifunctional passivation agent to modify buried SnO2/perovskite and perovskite/hole transport layer (HTL) interfaces. Upon incorporation of CF3PhAI between SnO2 and perovskite, CF3PhAI can chemically link to SnO2 via Lewis coordination and electrostatic coupling, thereby effectively passivating under-coordinated Sn and filling the oxygen vacancy. Meanwhile, CF3PhAI helps anchor PbI2 and organic cations (MA+/FA+) to control the crystallization of the perovskite. Consequently, reduced interfacial defects, homogeneous perovskite crystallites, and better energetic alignment can be simultaneously achieved. When CF3PhAI was further used to modify the perovskite/HTL interface, the fabricated PSCs yielded an impressive power conversion efficiency of 23.06% together with negligible J–V hysteresis. The unencapsulated devices exhibited long-term stability in wet conditions (91.8% efficiency retention after 1000 h) due to the water-resistant CF3PhAI. We also achieved good light soaking stability, maintaining 86.1% of its initial efficiency after aging for 720 h. Overall, our finding provides a promising strategy for modifying the dual contact interfaces of PSCs toward improved efficiency and stability.