Trion-to-exciton upconversion dynamics in monolayer WSe2
Wenze Lan, Jing Wang, Ming Xin, Yuan Huang, Changzhi Gu, Baoli Liu
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.
Topics & Concepts
TrionPhoton upconversionTungsten diselenideExcitonFemtosecondMonolayerMaterials scienceStreak cameraSpectroscopyUltrashort pulseBiexcitonRaman spectroscopyPhotoluminescenceOptoelectronicsOpticsCondensed matter physicsLaserChemistryPhysicsNanotechnologyDopingTransition metalQuantum mechanicsBiochemistryCatalysisPerovskite Materials and Applications2D Materials and ApplicationsChalcogenide Semiconductor Thin Films