Dynamic lattice disorder overrides energetics for barrierless interfacial charge transfer in 2D hybrid perovskites

Two-dimensional (2D) hybrid perovskites show promise in charge transfer (CT) applications, yet how their inherent dynamic lattice disorder redefines the CT dynamics remains unresolved. Using tetrathiophene-based 2D perovskites 4Tm₂MA_n-1Pb_nI_3n+1 (n = 1 to 4), we reveal a general two-step CT process: ultrafast hole transfer followed by slower electron transfer from inorganic layer to form triplets in organic ligands. Strikingly, despite a broad driving force range (0.16 to 0.75 electron volts), CT rates increase monotonically with decreasing inorganic layer number n, exhibiting no Marcus inverted region behavior and negligible temperature dependence (80 to 295 kelvin). Such anomalous barrierless CT behavior cannot be described by classical Marcus CT or quantum tunneling models. We propose a dynamic lattice CT model where lattice fluctuation enables sampling a wide spectrum of transient lattice configurations, allowing CT to always proceed via barrierless pathways. This model, validated by ab initio calculations, establishes dynamic lattice disorder as a fundamental design principle for efficient CT in anharmonic materials, transcending conventional energetic constraints.