Scaling and high-quality insulators are crucial for the fabrication of 2D/3D hybrid vertical electronic devices, such as metal-oxide-semiconductor (MOS)-based Schottky diodes and hot-electron transistors, whose production is limited by the scarcity of bulk layered wide-bandgap semiconductors. In this study, a new two-dimensional insulating monolayer of InO₂ was synthesized over a large area (>300 μm²) by intercalation at the epitaxial graphene (EG)/SiC interface.Its stoichiometry is different from its bulk form. By adjusting the lateral size of graphene through optical lithography before intercalation and tuning the thickness of InO₂ to be 85% monolayer, the preference for monolayer formation of InO₂ was explained using molecular dynamics and density functional theory (DFT) calculations. In addition, the bandgap of InO₂ is calculated to be 4.1 eV, which differs from its bulk form (2.7 eV).In addition, measurements of InO₂-interlayered EG/n-SiC using MOS-based Schottky diodes indicate that the EG/n-SiC junction converts from an ohmic contact to a Schottky contact upon interlayering, with a barrier height of 0.87 eV and a rectification ratio of ≈10⁵. These findings introduce a new member to the series of two-dimensional insulators, demonstrating the utility of monolayer InO₂ as a barrier in vertical electronic devices.

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https://www.x-mol.com/paper/1988049202536624128/t?adv