Influence of Polymorphism on the Electronic Structure of Ga${}_2$O${}_3$

Abstract

The search for new wide band gap materials is intensifying to satisfy the need for more advanced and energy efficient power electronic devices. Ga${}_2$O${}_3$ has emerged as an alternative to SiC and GaN, sparking a renewed interest in its fundamental properties beyond the main $\beta$-phase. Here, three polymorphs of Ga${}_2$O${}_3$, $\alpha$, $\beta$ and $\epsilon$, are investigated using X-ray diffraction, X-ray photoelectron and absorption spectroscopy, and ab initio theoretical approaches to gain insights into their structure - electronic structure relationships. Valence and conduction electronic structure as well as semi-core and core states are probed, providing a complete picture of the influence of local coordination environments on the electronic structure. State-of-the-art electronic structure theory, including all-electron density functional theory and many-body perturbation theory, provide detailed understanding of the spectroscopic results. The calculated spectra provide very accurate descriptions of all experimental spectra and additionally illuminate the origin of observed spectral features. This work provides a strong basis for the exploration of the Ga${}_2$O${}_3$ polymorphs as materials at the heart of future electronic device generations.

arXiv commentUpdated manuscript version after peer review

References in corpus (10)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Quasiparticle band structure based on a generalized Kohn-Sham scheme
• Intrinsic Electron Mobility Limits in beta-Ga2O3
• Electron Mobility in Monoclinic β-Ga2O3 - Effect of Plasmon-phonon Coupling, Anisotropy, and Confinement
• Low temperature growth and optical properties of α-Ga2O3 deposited on sapphire by plasma enhanced atomic layer deposition
• Addressing electron-hole correlation in core excitations of solids: An all-electron many-body approach from first principles
• Revisiting the origin of satellites in core level photoemission of transparent conducting oxides: the case of $n$-doped SnO${}_2$
• Atomic signatures of local environment from core-level spectroscopy in $\beta$-Ga${}_2$O${}_3$
• The electrical conductivity tensor of $\beta$-Ga2O3 analyzed by van der Pauw measurements: Inherent anisotropy, off-diagonal element, and the impact of grain boundaries

Cited by in corpus (1)

• Complex ${\mathrm{Ga}}_2{\mathrm{O}}_3$ Polymorphs Explored by Accurate and General-Purpose Machine-Learning Interatomic Potentials