【Others Papers】Investigation on the structural and electronic property of monoclinic Al₂O₃/Ga₂O₃ superlattice with varying layer periods

      Researchers from the Hong Kong University of Science and Technology (Guangzhou) have published a dissertation titled "Investigation on the structural and electronic property of monoclinic Al₂O₃/β-Ga₂O₃ superlattice with varying layer periods" in Applied Physics Letters.

Abstract

      In this study, we employ first-principles calculations to explore the structural and electronic properties of monoclinic Al₂O₃/Ga₂O₃ superlattices with varied layer thickness and to perform a comparative analysis with (Al_xGa_1−x)₂O₃ alloys. Our investigation examines the lattice constants and electronic energy bandgaps of both the superlattice structures and alloys across different Al concentrations, shedding light on the intricate relationship between composition and electronic properties. The analysis on electronic properties reveals that as the number of Al₂O₃ monolayers in the Al₂O₃/Ga₂O₃ superlattice rises from 2 to 6 monolayers, the bandgap correspondingly expands from 5.29 to 6.43 eV. The band alignment between monoclinic Al₂O₃ and Ga₂O₃ exhibits a type-II band alignment. The conduction and valence band offsets between the bulk material and Al₂O₃/Ga₂O₃ superlattice varies with change in the number of Al₂O₃ monolayers. Our study gives a deeper insight into the properties of the Al₂O₃/Ga₂O₃ superlattice and suggests a solution to the Al-phase separation issue in (Al_xGa_1−x)₂O₃ alloys for advanced semiconductor device applications.

DOI：

https://doi.org/10.1063/5.0252684