ab initio electronic transport model for photovoltaics

Accurate ab initio electronic transport models facilitate the rapid development in design of new photovoltaic (PV) materials. In order to correctly predict low-field electronic drift mobility and conductivity of semiconductors, we present here an ab initio transport Model in the Boltzmann Transport (aMoBT) framework. Using the relevant inputs from ab initio band structure and density of states of the semiconductor, we calculate electron group velocity, effective mass, orbital hybridization, and phonon frequencies. We then explicitly solve the linearized Boltzmann transport equation (BTE) via Rode´s iterative method, to calculate the perturbation to a small electric field and, thus, drift mobility, without the need for experimental data and fitting. We have validated the calculated mobility of GaAs and InN against experimental data and find that the agreement is satisfactory in both the qualitative prediction of changes of mobility with temperature and carrier concentration, as well as the quantitatively predicted values. We believe that this tool facilitates high- throughput density functional theory calculations in search of new PV materials. Furthermore, it offers insight on physical limitations to mobility, including elastic and inelastic scattering mechanisms inside these materials.