Bandgap engineering of α-Ga <sub>2</sub> O <sub>3</sub> by hydrostatic, uniaxial, and equibiaxial strain
Takahiro Kawamura, Toru Akiyama
Abstract
Abstract Ga 2 O 3 is a wide bandgap semiconductor and an understanding of its bandgap tunability is required to broaden the potential range of Ga 2 O 3 applications. In this study, the different bandgaps of α -Ga 2 O 3 were calculated by performing first-principles calculations using the pseudopotential self-interaction correction method. The relationships between these bandgaps and the material’s hydrostatic, uniaxial, and equibiaxial lattice strains were investigated. The direct and indirect bandgaps of strain-free α -Ga 2 O 3 were 4.89 eV and 4.68 eV, respectively. These bandgap values changed linearly and negatively as a function of the hydrostatic strain. Under the uniaxial and equibiaxial strain conditions, the maximum bandgap appeared under application of a small compressive strain, and the bandgaps decreased symmetrically with increasing compressive and tensile strain around the maximum value.