Density Functional Theory-based study of charge transfer in doped silicon nanowire with gold leads: A toy model for the p-n junction photovoltaic device

We analyze a toy model for p-n junction photovoltaic devices by simulating photoexcited state dynamics in silicon nanowires doped with aluminum and phosphorus atoms and capped with gold leads. We use Boltzmann transport equation (BE) that includes phonon emission, carrier multiplication (CM), and exciton transfer. BE rates are computed using non-equilibrium finite-temperature many-body perturbation theory (MBPT) based on Density Functional Theory simulations, including excitonic effects from Bethe-Salpeter Equation (see A. Kryjevski, D. Mihaylov, and D. Kilin, J. of Phys. Chem. Lett., 9(19) (2018), A. Kryjevski, D.Mihaylov, S. Kilina, and D. Kilin, J. of Chem. Phys., 147, 154106 (2017)). We compute total charge transfer amount generated from the initial photoexcitation and find an enhancement when CM is included.