Negative Schottky Barriers and Spin-Polarized Fermi Crossings at WSe<sub>2</sub>/NbSe<sub>2</sub> Interfaces.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41736239.
- Also identified by DOI 10.1021/acsnano.5c22009 and PMC identifier 12981010.
- 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
Discovering and engineering spin-polarized surface states in the electronic structures of condensed matter systems is a crucial first step in the development of spintronic devices, wherein spin-polarized bands crossing the Fermi level can facilitate information transfer. Here, through nanofocused angle-resolved photoemission spectroscopy (nano-ARPES) and density functional theory-based calculations, we show that the interface between monolayer WSe<sub>2</sub> and metallic NbSe<sub>2</sub> exhibits a negative Schottky barrier height of ∼ -30 meV: the K-point valleys of the semiconducting layer are shifted by ∼800 meV to produce a surface-localized Fermi surface populated only by spin-polarized charge carriers. By increasing the WSe<sub>2</sub> thickness, the Fermi pockets can be moved from K to Γ, demonstrating tunability of novel semimetallic phases that exist atop a substrate additionally possessing charge density wave and superconducting phases. Together, this study provides a spectroscopic understanding into p-type, Schottky barrier-free interfaces, which are of urgent interest for bypassing the limitations of current-generation vertical field effect transistors, in addition to longer-term spintronics development.