Charge localization control of electron-hole recombination in multilayer two-dimensional Dion-Jacobson hybrid perovskites

Two-dimensional (2D) Dion-Jacobson (DJ) organic-inorganic hybrid halide perovskites hold great potential for optoelectronics and solar cells. Interestingly, experimental excited-state lifetime is longer in (3AMP)(MA)(n-1)PbnI3n+1 than (4AMP)(MA)(n-1)PbnI3n+1 (3AMP = 3-(aminomethyl)piperidinium, 4AMP = 4-(aminomethyl)piperidinium, MA = CH3NH3+) regardless of the value of n despite 3AMP having a smaller bandgap. Using ab initio nonadiabatic (NA) molecular dynamics combined with time-domain density functional theory, we focus on the n = 2 perovskite and demonstrate that stronger hydrogen bonding interaction and larger octahedral tilting cause significant delocalization of the hole wave function in (4AMP)(MA)Pb2I7 and accelerates the electron-hole recombination by a factor of 5 compared to (3AMP)(MA)Pb2I7 due to an increased NA coupling. The inorganic component stretching mode and coupled inorganic and organic collective motions accelerate decoherence to sub-4 fs in the two materials. The simulations rationalize the experimentally observed puzzle of excited-state lifetime in the 2D DJ perovskite and suggest a rational way to optimize the performance of perovskite devices.