Accommodation at the interface of highly dissimilar GaN(0 0 0 1)/Sc2O3(1 1 1) heteroepitaxial systems

We present first-principles calculations to study the heterojunction between a wurtzite GaN(0 0 0 1) film and a cubic Sc2O3(1 1 1) substrate. We report that the most favorable interface consists of the graphitic-like GaN nanofilms, indicating that the nanofilms can accommodate the misfit strain relaxation at heteroepitaxial interfaces. This interface structure gives rise to Ga polarity in the GaN(0 0 0 1) epitaxial film. Our findings agree with previously reported experimental results.