Photoexcited charge carrier behaviors in solar energy conversion systems from theoretical simulations

Abstract

AbstractSolar energy bears great potential in the substitution of conventional fossil fuels to enable a sustainable world. In order to harness and use solar energy, photocatalytic and photovoltaic systems made of semiconductor materials have been developed to convert sunlight into energy (electricity) based on the photoelectrochemical effects. Photoelectric events are related with the light–energy (electricity) conversion process, including photon absorption, photoexcited charge carrier separation and recombination, charge carrier transport, and photocurrent generation, as well as electron plasmonic resonance. We focus on the recent state‐of‐the‐art simulation methods correspondingly mimicking these photogenerated charge carrier behaviors, taking electron–phonon, electron–exciton, and exciton–exciton interactions into account. Results can be obtained from the standard density function theory (DFT) for ground‐state properties, many‐body perturbation theory for band gap renormalization and optical absorption, time‐domain DFT in combination with nonadiabatic molecular dynamics for photoexcitation dynamics, nonequilibrium Green's function and self‐consistent theory for charge carrier transport properties, and classical Maxwell's equations in discrete dipole approximation for localized surface plasmon resonance absorption and near‐field enhancement. In combination of the results from these simulation methods, a complete and consistent picture describing the fundamental photoelectric process in light–energy (electricity) conversion could be obtained. Simulation results offer guidelines for experimental efforts and provide new basic insights into the underlying mechanisms and the design principles for next‐generation photocatalytic and photovoltaic devices of high solar light utilization efficiency.This article is categorized under: Structure and Mechanism > Computational Materials Science Electronic Structure Theory > Ab Initio Electronic Structure Methods Software > Simulation Methods