WSe<sub>2</sub> Monolayers Grown by Molecular Beam Epitaxy on hBN.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41353649.
- Also identified by DOI 10.1021/acs.nanolett.5c04228 and PMC identifier 12715837.
- 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
A three-step process was developed for growing high-quality, optically uniform WSe<sub>2</sub> monolayers by molecular beam epitaxy (MBE), taking advantage of the use of hexagonal boron nitride (hBN) as a substrate. The process was optimized to maximize the efficiency of photoluminescence and promote the formation of hexagonal WSe<sub>2</sub> domains. Atomic force microscopy was employed to estimate the dispersion of the WSe<sub>2</sub> hexagonal domains' orientation. Monolayer character of the film was identified using optical methods and verified with a high-resolution transmission electron microscopy cross-section. Temperature- and magnetic-field-dependent studies revealed the behavior of exciton complexes to be analogous to that of exfoliated counterparts. Direct growth on hBN, combined with a uniform optical response, proves that MBE-grown WSe<sub>2</sub> is superior to mechanically exfoliated WSe<sub>2</sub> in terms of the convenience of use and reproducibility. The provided results establish significant progress in the optical quality of epitaxially grown transition-metal dichalcogenide monolayers and the fabrication of large-scale functional devices.