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Anti‐Stokes Photoluminescence of Monolayer WS 2
Author(s) -
Pierret Aurélie,
Tornatzky Hans,
Maultzsch Janina
Publication year - 2019
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201900419
Subject(s) - photoluminescence , monolayer , excitation , phonon , exciton , luminescence , stokes shift , materials science , laser , optoelectronics , condensed matter physics , atomic physics , nanotechnology , optics , physics , quantum mechanics
Anti‐Stokes photoluminescence excitation of a WS 2 monolayer flake between 10 and 300 K is reported herein. Even with continuous‐wave lasers at low power, the emission of the exciton at excitation 100 meV below its emission energy at room temperature is observed. A mechanism which involves the trions as the intermediate state is proposed, leading to an efficient up‐conversion process. In addition, it is demonstrated that phonons are the source of the additional energy needed by the system. Overall, the results provide evidence that anti‐Stokes luminescence in transition metal dichalcogenides is very efficient.