Room temperature multi-phonon upconversion photoluminescence in monolayer semiconductor WS<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30631049.
- Also identified by DOI 10.1038/s41467-018-07994-1 and PMC identifier 6328540.
- 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
Photon upconversion is an anti-Stokes process in which an absorption of a photon leads to a reemission of a photon at an energy higher than the excitation energy. The upconversion photoemission has been already demonstrated in rare earth atoms in glasses, semiconductor quantum wells, nanobelts, carbon nanotubes and atomically thin semiconductors. Here, we demonstrate a room temperature upconversion photoluminescence process in a monolayer semiconductor WS<sub>2</sub>, with energy gain up to 150 meV. We attribute this process to transitions involving trions and many phonons and free exciton complexes. These results are very promising for energy harvesting, laser refrigeration and optoelectronics at the nanoscale.