Abstract
We investigate the trion-to-exciton upconversion dynamics in a large-scale mechanically exfoliated tungsten diselenide (WSe2) monolayer covered by poly(methyl methacrylate) using two-color ultrafast pump-probe spectroscopy. With resonantly pumping the trion and probing the exciton transitions, we find a fast trion-to-exciton upconversion process with the upconversion time about ∼2 ps. Combined with the temperature-dependent transient reflection and helicity-resolved Raman measurements, we further demonstrate that the upconversion is indeed a phonon-mediated process in our sample.
Original language | English |
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Article number | 083107 |
Journal | Applied Physics Letters |
Volume | 117 |
Issue number | 8 |
DOIs | |
Publication status | Published - 24 Aug 2020 |
Externally published | Yes |