Ab Initio Electron Transport in Monoclinic beta-Ga 2O

This dissertation reports a comprehensive study of electron transport in monoclinic beta-Ga2O3 from first principles. In spite of being an extremely promising candidate for next generation power electronics and optoelectronics applications, the electron transport theory in this material is rarely explored due to its low symmetry crystal and large primitive unit cell. In this dissertation a bottom-up approach is used to systematically study the microscopic picture of electron-phonon and electron-electron interactions and to explore how they impact the electron transport both near equilibrium and far-from equilibrium. A combination of density functional theory based electronic structure and lattice dynamical computations with Boltzmann theory based transport calculations reveals deep insights on the peculiarities of the non-equilibrium electron dynamics in monoclinic crystals. Modewise contribution of electron-phonon scattering is investigated to identify dominant scattering channels in different regimes of transport. Electron-electron interaction is investigated to capture the ionization of ground state electrons caused by highly excited electronic states. Low-field electron mobility, velocity-field curves, and impact ionization co-efficients are estimated in different Cartesian directions to guide device design.