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 cell. Interestingly, experimental excited−state lifetime is longer in (3AMP)(MA)n−1PbnI3n+1 than (4AMP)(MA)n−1PbnI3n+1 (3AMP=3−(aminomethyl)piperidinium, 4AMP=4−(aminomethyl)piperidinium) regardless of the value of n despite the 3AMP has smaller bandgap and the two materials have similar decoherence times. Using ab initio nonadiabatic (NA) molecular dynamics combined with time−domain density functional theory, we focus on n=2 perovskite and demonstrate that stronger hydrogen bonding interaction and larger octahedron tilting cause significant delocalization of electron wave function in the (4AMP)(MA)Pb2I7 and accelerates the electron−hole recombination by a factor of 5 compared to the (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. The simulations rationalize the experimentally observed puzzle of excited−state lifetime in 2D DJ perovskite and suggest a rational way to optimize the performance of perovskite device.