First-principles study of electron-phonon interactions and transport in anatase TiO2

Abstract

Electron transport in anatase TiO2, which has important applications in oxide electronics and photocatalysis, is still poorly understood. We investigate the electron mobility in anatase TiO2 by performing first-principles calculations of electron and phonon spectra as well as electron-phonon coupling. The formation of large polarons (quasiparticles formed by electrons interacting with phonons in a polar medium) leads to a renormalization of the electronic band structure, which we address using many-body perturbation theory. We correlate the lowering of the mobility of these quasiparticles to the renormalization of band velocities due to the electron-phonon interaction. These results explain why the mobility decreases with increasing temperature, as observed in experiments.