Valley dynamics probed through charged and neutral exciton emission in monolayer WSe2

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 4ps, 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 about 20%, for which a typical valley polarization decay time larger than 1ns can be inferred. This is a clear signature of stable, optically initialized valley polarization.

16 pages, 9 figures

References in corpus (16)

• Two Dimensional Atomic Crystals
• High Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts
• Electrically Tunable Excitonic Light Emitting Diodes based on Monolayer WSe2 p-n Junctions
• Valley filter and valley valve in graphene
• Optical Spectrum of MoS${}_2$: Many-body Effects and Diversity of Exciton States
• Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
• Optical signature of symmetry variations and spin-valley coupling in atomically thin tungsten dichalcogenides
• Robust optical emission polarization in MoS2 monolayers through selective valley excitation
• Large spin splitting in the conduction band of transition metal dichalcogenide monolayers
• Vapor-Solid Growth of High Optical Quality MoS2 Monolayers With Near-Unity Valley Polarization
• Bright excitons in monolayer transition metal dichalcogenides: from Dirac cones to Dirac saddle points
• Valley depolarization due to inter- and intra-valley electron-hole exchange interactions in monolayer MoS${}_2$
• Exciton fine structure and spin decoherence in monolayers of transition metal dichalcogenides
• Valley Carrier Dynamics in Monolayer Molybdenum Disulphide from Helicity Resolved Ultrafast Pump-probe Spectroscopy
• Unconventional Quantum Hall Effect and Tunable Spin Hall Effect in MoS2 Trilayers
• Coherent Electronic Coupling in Atomically Thin MoSe2

Cited by in corpus (153)

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