Bandgap engineering of α-Ga2O3 by hydrostatic, uniaxial, and equibiaxial strain

• Published in: Japanese Journal of Applied Physics Vol. 61; no. 2; pp. 021005 - 21012
• Main Authors: Kawamura, Takahiro, Akiyama, Toru
• Format: Journal Article
• Language: English
• Published: Tokyo IOP Publishing 01.02.2022; Japanese Journal of Applied Physics
• Subjects: a-Ga; bandgap; Compressive properties; First principles; first-principles calculation; Gallium oxides; Lattice strain; Mathematical analysis; Tensile strain; Wide bandgap semiconductors
• ISSN: 0021-4922; 1347-4065
• DOI: 10.35848/1347-4065/ac468f

Ga2O3 is a wide bandgap semiconductor and an understanding of its bandgap tunability is required to broaden the potential range of Ga2O3 applications. In this study, the different bandgaps of α-Ga2O3 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-Ga2O3 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.