2D Indium Oxide at the Epitaxial Graphene/SIC Interface: Synthesis, Structure, Properties, and Devices.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41211837.
- Also identified by DOI 10.1002/adma.202516133 and PMC identifier 12848651.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Scaled and high-quality insulators are crucial for fabricating 2D/3D hybrid vertical electronic devices such as metal-oxide-semiconductor (MOS) based Schottky diodes and hot electron transistors, the production of which is constrained by the scarcity of bulk layered wide bandgap semiconductors. In this research, the synthesis of a new 2D insulator, monolayer InO<sub>2</sub>, which differs in stoichiometry from its bulk form is presented, over a large area (>300 µm<sup>2</sup>) by intercalating at the epitaxial graphene (EG)/SiC interface. By adjusting the lateral size of graphene through optical lithography prior to the intercalation, the thickness of InO<sub>2</sub> is tuned such that it is 85% monolayer. The preference for monolayer formation of InO<sub>2</sub> is explained using molecular dynamics and density functional theory (DFT) calculations. Additionally, the bandgap of InO<sub>2</sub> is calculated to be 4.1 eV, differing from its bulk form (2.7 eV). Furthermore, MOS-based Schottky diode measurements on InO<sub>2</sub> intercalated EG/n-SiC demonstrate that the EG/n-SiC junction transforms from ohmic to a Schottky junction upon intercalation, with a barrier height of 0.87 eV and a rectification ratio of ≈10<sup>5</sup>. These findings introduce a new addition to the 2D insulator family, demonstrating the utility of monolayer InO<sub>2</sub> as a barrier in vertical electronic devices.