Computational design of optimal heterostructures for $β$-Ga$_2$O$_3$

Sierra Seacat; John L. Lyons; Hartwin Peelaers

doi:10.1103/PhysRevMaterials.8.014601

paper

Computational design of optimal heterostructures for $β$ -Ga $_{2}$ O $_{3}$

arXiv:2310.10557 · doi:10.1103/PhysRevMaterials.8.014601

Abstract

Ga $_{2}$ O $_{3}$ is a wide-bandgap material of interest for a wide variety of devices, many of these requiring heterostructures, for instance to achieve carrier confinement. A common method to create such heterostructures is to alloy with In $_{2}$ O $_{3}$ or Al $_{2}$ O $_{3}$ . However, the lattice constants of these materials are significantly different from those of Ga $_{2}$ O $_{3}$ , leading to large amounts of strain in the resulting heterostructure. If the thickness of the heterostructure is increased, this can lead to cracking. By considering alloys of In $_{2}$ O $_{3}$ and Al $_{2}$ O $_{3}$ , the lattice constants can be tailored to those of Ga $_{2}$ O $_{3}$ , while still keeping a sizable conduction-band offset. We use density functional theory with hybrid functionals to investigate the structural and electronic properties of In $_{2}$ O $_{3}$ and Al $_{2}$ O $_{3}$ alloys in the bixbyite, corundum, and monoclinic structures. We find that the lattice constants increase with In incorporation. Bandgaps decrease nonlinearly with increasing In concentration. We find the (In $_{0.25}$ Al $_{0.75}$ ) $_{2}$ O $_{3}$ monoclinic structure to be of particular interest, as it closely matches the Ga $_{2}$ O $_{3}$ lattice constants while providing an indirect/direct bandgap of 5.94/5.70 eV and a conduction-band offset of 1 eV compared to Ga $_{2}$ O $_{3}$ .

6 pages, 5 figures

Computational design of optimal heterostructures for β-Ga2​O3​

Abstract

References in corpus (2)

Computational design of optimal heterostructures for $β$ -Ga $_{2}$ O $_{3}$