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

Abstract

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−1Pb_nI_3n+1 than (4AMP)(MA)_n−1Pb_nI_3n+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.