Strain Effects on the Electronic States, Phonon Modes, and Electron-Phonon Coupling in Cubic Spinel ZnGa2O4

In recent years, ultra-wide bandgap ZnGa₂O₄ (ZGO) has become of great interest as a potential candidate in high power semiconductor device applications. The material possesses highly desirable electrical characteristics and has been synthesized as thin-films using PLD and MOCVD techniques on a number of substrate materials. To better characterize the properties of these PLD grown materials, we utilize first-principles calculations to determine the role of strain on the band structure, lattice configuration, phonon properties and electron-phonon coupling. By adopting hybrid functionals in a density functional theory framework, we observe the strain-dependence on the indirect bandgap of ZGO and construct the numerical deformational potential coefficients. Similarly, we present the dependence of raman-active phonon modes on uniaxial and hydrostatic strain and give raman coefficients of the ideal material. The results presented here will facilitate rapid and non-destructive strain characterization of PLD grown ZGO films as well as strain-engineering electrical properties such as mobility.  We combine these with the effect of strain on electron-phonon scattering rates to gain an insight into key factors affecting the carrier mobility