Alloying orthorhombic Ga<sub>2</sub>O<sub>3</sub> with Al<sub>2</sub>O<sub>3</sub> /In<sub>2</sub>O<sub>3</sub>

ORAL

Abstract

Ga2O3 is a wide-bandgap semiconductor with promising applications in high-power devices and UV photodetectors. It occurs in several polymorphs, with monoclinic β-gallia as the thermodynamically stable phase. Other polymorphs of Ga2O3 can be stabilized as well, but are less studied. The κ-polymorph is of interest, as it possesses ferroelectric properties and exhibits large spontaneous electrical polarizations.
Here we use density functional theory with hybrid functionals to elucidate how alloying with Al2O3 and In2O3 can be used to modify the structural and electronic properties. We focus on how the lattice constants and bandgaps can be tuned as a function of Al/In concentration. Our results show that the lattice constants vary linearly following Vegard’s law. The bandgap changes nonlinearly, with the Al alloys exhibiting a larger bandgap bowing [1]. We also report the absolute alignments of valence and conduction bands. These results can be used to guide the experimental design of new devices.

[1] S. Seacat, J.L. Lyons, and H. Peelaers. Appl. Phys. Lett. 116, 232102 (2020)

*Work supported by the Office of Naval Research through the Naval Research Laboratory’s Basic Research Program.

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Presenters

  • Sierra Seacat

    • Department of Physics and Astronomy, University of Kansas

Authors

  • Sierra Seacat

    • Department of Physics and Astronomy, University of Kansas

  • John Lyons

    • Center for Computational Materials Science, United States Naval Research Laboratory
    • Center for Computational Materials Science, US Naval Research Laboratory, Washington, DC 20375, USA
    • United States Naval Research Laboratory
    • Center for Computational Materials Science, US Naval Research Laboratory

  • Hartwin Peelaers

    • Department of Physics and Astronomy, University of Kansas
    • 2. Department of Physics and Astronomy, University of Kansas
    • University of Kansas