Nuclear Quantum Effects Prolong Charge Carrier Lifetimes in Hybrid Organic-Inorganic Perovskites

Hybrid organic-inorganic perovskites (HOIPs) containlighthydrogen atoms that exhibit significant nuclear quantum effects (NQEs).We demonstrate that NQEs have a strong effect on HOIP geometry andelectron-vibrational dynamics at both low and ambient temperatures,even though charges in HOIPs reside on heavy elements. By combiningring-polymer molecular dynamics (MD) and ab initio MD with nonadiabaticMD and time-dependent density functional theory and focusing on themost studied tetragonal CH3NH3PbI3, we show that NQEs increase the disorder and thermal fluctuationsthrough coupling of the light inorganic cations to the heavy inorganiclattice. The additional disorder induces charge localization and decreaseselectron-hole interactions. As a result, the nonradiative carrierlifetimes are extended by a factor of 3 at 160 K and 1/3 at 330 K.The radiative lifetimes are increased by 40% at both temperatures.The fundamental band gap decreases by 0.10 and 0.03 eV at 160 and330 K, respectively. By enhancing atomic motions and introducing newvibrational modes, NQEs strengthen electron-vibrational interactions.Decoherence, determined by elastic scattering, accelerates almostby a factor of 2 due to NQEs. However, the nonadiabatic coupling,driving nonradiative electron-hole recombination, decreasesbecause it is more sensitive to structural distortions than atomicmotions in HOIPs. This study demonstrates, for the first time, thatNQEs should be considered to achieve an accurate understanding ofgeometry evolution and charge carrier dynamics in HOIPs and providesimportant fundamental insights for the design of HOIPs and relatedmaterials for optoelectronic applications.