Fermi-level depinning achieved by high-work-function Au<sub>1-x</sub>Se<sub>x</sub> alloy contacts for high-performance p-type WSe<sub>2</sub> transistors.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42265095.
- Also identified by DOI 10.1038/s41467-026-74149-y.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
P-type contact in two-dimensional (2D) transition metal dichalcogenides (TMDs) faces more severe Fermi-level pinning (FLP) than their n-type counterparts due to the damage caused by high-work-function metal deposition. Here, we demonstrate a simple molecular beam epitaxy (MBE) contact strategy using a high-work-function (5.8 eV) Au<sub>1-x</sub>Se<sub>x</sub> alloy to achieve Fermi-level depinning in monolayer WSe<sub>2</sub> p-type transistors. The Au<sub>1-x</sub>Se<sub>x</sub> alloy mitigates both defect-induced gap states (DIGS) and metal-induced gap states (MIGS) by gentle pre-deposition of selenium (Se) followed by the conversion to Au<sub>1-x</sub>Se<sub>x</sub> alloy by deposition of Au at low-temperature, forming a van der Waals (vdW) interface between Au<sub>1-x</sub>Se<sub>x</sub> and monolayer WSe<sub>2</sub>. Moreover, it imposes hole doping to the contacted monolayer WSe<sub>2</sub>, reducing the Schottky barrier height and enabling favorable p-type device performance. Combined experimental and theoretical analyses confirm quasi-ohmic contact behavior, yielding a contact resistance of 492 Ω·µm, an on-current of 385 µA/µm, and an on/off ratio greater than 10<sup>8</sup> for a p-FET with a 100 nm channel length. This work establishes Au<sub>1-x</sub>Se<sub>x</sub> alloy contacts as a scalable solution for high-performance p-type 2D electronics.