Synergistically Stabilizing Hole Transport Layer and Dual Interface Enables High-Performance Perovskite Solar Cells

The migration and diffusion of Li + and halide ions, as well as the volatilization of 4-tert butylpyridine ( t BP), seriously restrain the long-term operational stability of n- i -p perovskite solar cells (PSCs). Herein, we employ l -glutamic acid dibenzyl ester 4-toluenesulfonate (GADET) to simultaneously modulate the hole transport layer (HTL) and buried interface, which stabilizes the HTL and minimizes interfacial energy loss by immobilizing Li +, t BP, and halide ions and passivating dual interface defects. After forming Spiro-OMeTAD •+ TFSI –, GADET impedes the Li + ion diffusion through the ionic bond interaction of P-methylbenzenesulfonate anion and Li +, while the formation of the hydrogen bond of −NH 3 + with t BP can suppress the volatilization of t BP. Moreover, the halide ion migration and interfacial trap-induced nonradiative recombination are inhibited via passivating undercoordinated Pb and halide vacancy defects based on multiple chemical bonds. The synergistically modified devices achieve a champion efficiency of 25.06% (certified PCE of 24.08%). Meanwhile, the stability of PSCs was significantly improved.