<i>k</i>-Resolved Ultrafast Light-Induced Band Renormalization in Monolayer WS<sub>2</sub> on Graphene.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39772760.
- Also identified by DOI 10.1021/acs.nanolett.4c06238 and PMC identifier 11760173.
- 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
Understanding and controlling the electronic properties of two-dimensional materials are crucial for their potential applications in nano- and optoelectronics. Monolayer transition metal dichalcogenides have garnered significant interest due to their strong light-matter interaction and extreme sensitivity of the band structure to the presence of photogenerated electron-hole pairs. In this study, we investigate the transient electronic structure of monolayer WS<sub>2</sub> on a graphene substrate after resonant excitation of the A-exciton using time- and angle-resolved photoemission spectroscopy. We observe a pronounced band structure renormalization, including a substantial reduction of the transient band gap in good quantitative agreement with our <i>ab initio</i> theory, revealing the importance of both intrinsic WS<sub>2</sub> and extrinsic substrate contributions. Our findings deepen the fundamental understanding of band structure dynamics in two-dimensional materials and offer valuable insights for the development of novel electronic and optoelectronic devices based on monolayer TMDs and their heterostructures with graphene.