Characterization of β-In₂Se₃/β-Ga₂O₃ Heterostructures grown by Plasma-Assisted Molecular Beam Epitaxy on c-Sapphire Substrates

Umeshwar Reddy Nallasani^1*, Ssu-Kuan Wu¹, Wu-Ching Chou¹

¹Department of Electrophysics, National Yang-Ming Chiao-Tung University, Hsinchu, Taiwan

* Presenter:Umeshwar Reddy Nallasani, email:umeshnalasani@gmail.com

The epitaxy of two-dimensional (2D) layered materials which rely on weak interlayer van der Waals (vdW) forces have revealed extraordinary opportunities to investigate new physics and device concepts. The extent of these layered materials can be significantly enhanced with the formation of heterostructures. The metal chalcogenide/metal oxide heterostructures with tuned bandgaps have been used for the efficient separation of photogenerated carriers which exhibits great potential in Photoelectrochemical and Opto-electrical applications. In this work, we present a brief overview of the epitaxy of Indium Selenide/Gallium Oxide heterostructures grown on c-sapphire substrates by Plasma-Assisted Molecular Beam Epitaxy (PA-MBE) at different epitaxial conditions. A two-stepped Ga₂O₃ buffer layer was grown at low and high substrate temperatures to enable better crystal quality for the growth of In₂Se₃ layers. The crystal quality, surface morphology along with optical properties of these heterostructures has been extensively studied in this work. The better crystal quality of β-In₂Se₃ layers was obtained when the epitaxy was maintained at comparatively high temperatures and lower Se/In ratio conditions.

Keywords: Chalcogenide, Indium Selenide, Plasma-Assisted Molecular beam epitaxy