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

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 (CFPhAI) is presented as a multifunctional passivation agent to modify buried SnO/perovskite and perovskite/hole transport layer (HTL) interfaces. Upon incorporation of CFPhAI between SnO and perovskite, CFPhAI can chemically link to SnO via Lewis coordination and electrostatic coupling, thereby effectively passivating under-coordinated Sn and filling the oxygen vacancy.