Structural, electronic and energetic properties of GaN[0 0 0 1]/Ga2O3[1 0 0] heterojunctions: A first-principles density functional theory study

We present first-principle calculations on the heterojunction between a wurtzite GaN(0 0 0 1) film and a monoclinic β-Ga2O3(1 0 0) substrate. The relative stability of different models of the GaN(0 0 0 1)/Ga2O3(1 0 0) interface was investigated and the most favorable interface consists of threefold- and sixfold-coordinated Ga. This interface structure gives rise to Ga-polarity in the GaN(0 0 0 1) epitaxial film. A detailed analysis of the electronic structure indicates that undistorted bonding at the interface stabilizes this structure between a wurtzite GaN(0 0 0 1) and a monoclinic β-Ga2O3(1 0 0).