Valley dynamics probed through charged and neutral exciton emission in monolayerWSe2

2014/02/24 by Gang Wang, G. Wang, L. Bouet +9 · 413 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Atomic physics #Chemistry #Condensed matter physics #Electron #Exciton #Graphene research and applications #Materials science #Monolayer #Nanotechnology #Optics #Perovskite Materials and Applications #Photoluminescence #Physical chemistry #Physics #Polarization (electrochemistry) #Quantum mechanics #Trion #cond-mat.mes-hall

paper · pdf · doi:10.1103/physrevb.90.075413

published in Physical Review B 90(7) (American Physical Society) · 16 pages, 9 figures

arxiv created 2014/02/24 · openalex publication_date 2014/08/18 · arxiv updated 2014/09/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

Optical interband transitions in monolayer transition metal dichalcogenides such as WSe₂ and MoS₂ are governed by chiral selection rules. This allows efficient optical initialization of an electron in a specific K valley in momentum space. Here we probe the valley dynamics in monolayer WSe₂ by monitoring the emission and polarization dynamics of the well-separated neutral excitons (bound electron-hole pairs) and charged excitons (trions) in photoluminescence. The neutral exciton photoluminescence intensity decay time is about 4 ps, whereas the trion emission occurs over several tens of ps. The trion polarization dynamics shows a partial, fast initial decay within tens of ps before reaching a stable polarization of \ensuremath≈20%, for which a typical valley polarization decay time of the order of 1 ns can be inferred.

Citations

• Single-layer MoS2 transistors
• Valley-selective circular dichroism of monolayer molybdenum disulphide
• Two-dimensional atomic crystals

Cited by

• Spin-Valley Relaxation of Rydberg Excitons
• Spin–flip processes and radiative decay of dark intravalley excitons in transition metal dichalcogenide monolayers
• Observation of Tunable Charged Exciton Polaritons in Hybrid Monolayer WS2−Plasmonic Nanoantenna System
• Optical Investigation of Monolayer and Bulk Tungsten Diselenide (WSe2) in High Magnetic Fields
• Ellipticity-Controlled Bright-Dark Coherence Transition in Monolayer WSe2
• Phonon-Assisted Photoluminescence from Indirect Excitons in Monolayers of Transition-Metal Dichalcogenides
• Trion formation dynamics in monolayer transition metal dichalcogenides
• Coupling Emission from Single Localized Defects in Two-Dimensional Semiconductor to Surface Plasmon Polaritons
• Nuclear surface acoustic resonance with spin-rotation coupling
• The valley Zeeman effect in inter- and intra-valley trions in monolayer WSe2
• Deterministic strain-induced arrays of quantum emitters in a two-dimensional semiconductor
• Dark-state impact on the exciton recombination of WS2 monolayers as revealed by multi-timescale pump-probe spectroscopy
• Chiral topological excitons in the monolayer transition metal dichalcogenides
• Valley polarization of exciton–polaritons in monolayer WSe 2 in a tunable microcavity
• Intrinsic exciton-state mixing and nonlinear optical properties in transition metal dichalcogenide monolayers
• Radiative lifetime of localized excitons in transition-metal dichalcogenides
• Engineering photonic environments for two‐dimensional materials
• Magnetic brightening and control of dark excitons in monolayer WSe2