Abstract
Phonon-assisted up conversion photoluminescence (UPL) is an anti-Stokes process emitting photons of energy higher than the excitation photons, with up conversion energy gain provided by optical phonons. Atomically thin transition metal dichalcogenides provide a promising platform for exploring the phonon-assisted UPL process due to their strong phonon-exciton interactions. Here, high-temperature phonon-assisted UPL process in monolayer WSe2 is investigated, aiming to understand the role of phonon population and the number of phonons involved in the UPL process at elevated temperatures. It is demonstrated that the integrated intensity of UPL emission significantly increases by two orders of magnitude as the temperature rises from room temperature of 295 to 476 K, which is distinguished from the photoluminescence emission usually suffering from thermal quenching. The observed growth of UPL emission intensity is attributed to both the increased phonon population and the reduced number of phonons required at elevated temperatures. Our study paves the way toward near-infrared light detection, anti-Stokes energy harvesting, optical refrigeration, and temperature sensing.
Recommended Citation
F. Meng et al., "High-temperature Phonon-assisted Upconversion Photoluminescence Of Monolayer WSe2," Applied Physics Letters, vol. 123, no. 1, article no. 013502, American Institute of Physics, Jul 2023.
The definitive version is available at https://doi.org/10.1063/5.0156364
Department(s)
Mechanical and Aerospace Engineering
International Standard Serial Number (ISSN)
0003-6951
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2023 American Institute of Physics, All rights reserved.
Publication Date
03 Jul 2023
Comments
Defense Advanced Research Projects Agency, Grant W911NF2110353