Nonradiative Recombination of Excitons in Periodic Solids: A Case Study of Dion-Jacobson Lead-Halide Perovskite.

Nonadiabatic dynamics describe the nonradiative relaxation of excited states in semiconducting materials which determine the efficiency of optoelectronic devices. Due to the computational complexity of modeling the coupled electronic-nuclear dynamics approximations are required. In the solid state a common approximation is the independent orbital approximation (IOA) as the electronic basis for surface-hopping trajectories describing nuclear dynamics. We examine the impact of the IOA on the computed nonradiative lifetimes in nanostructured Dion-Jacobson lead-halide perovskite. Specifically, we compute the nonadiabatic couplings between the excited states and the ground state using either IOA or many-body states to propagate the surface-hopping trajectories. Many-body corrections renormalize the nonadiabatic couplings compared to the IOA resulting in a 50% increase in the time-averaged coupling strength. However, when including decoherence corrections the differences in the computed recombination lifetimes reduce significantly. This result suggests that the IOA serves as an efficient approximation for prediction of nonradiative lifetimes in strongly confined nanomaterials.