First principles deformation potential extraction and computationally efficient mobility calculations

Based on density functional theory (DFT) and density functional perturbation theory (DFPT), we have developed a first-principles framework to extract acoustic, optical, and inter-valley deformation potentials from the short-range electron-phonon (e-ph) matrix elements, for incorporation with the Boltzmann transport equation (BTE). Using the BTE based on a numerical simulator that allows for the incorporation of e-ph scattering and ionized impurity scattering (IIS), we are able to compute a comparable mobility with results from advanced first principles calculations for Si. The method we present would be the middle ground computationally between the constant relaxation time (CRT) approximation and ab initio relaxation time extraction with ultra-dense grids, while providing first principles accuracy. We describe the method for Si, but it can be generalized and applied to other solid-state semiconductors and insulators, with much higher computational efficiency compared to fully ab initio simulations.