Probing the spin-polarized electronic band structure in monolayer transition metal dichalcogenides by optical spectroscopy
arXiv:1702.05647 · doi:10.1021/acs.nanolett.6b03855
Abstract
We study the electronic band structure in the K/K' valleys of the Brillouin zone of monolayer WSe2 and MoSe2 by optical reflection and photoluminescence spectroscopy on dual-gated field-effect devices. Our experiment reveals the distinct spin polarization in the conduction bands of these compounds by a systematic study of the doping dependence of the A and B excitonic resonances. Electrons in the highest-energy valence band and the lowest-energy conduction band have antiparallel spins in monolayer WSe2, and parallel spins in monolayer MoSe2. The spin splitting is determined to be hundreds of meV for the valence bands and tens of meV for the conduction bands, which are in good agreement with first principles calculations. These values also suggest that both n- and p-type WSe2 and MoSe2 can be relevant for spin- and valley-based applications
13 pages, 4 figures
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- Many-body exciton and inter-valley correlations in heavily electron-doped WSe monolayers
- WSe2/WS2 moiré superlattices: a new Hubbard model simulator
- Tuning exciton recombination rates in doped transition metaldichalcogenides
- Trion-trion annihilation in monolayer WS
- Monolayer Semiconductor Auger Detector
- Flat-band-induced many-body interactions and exciton complexes in a layered semiconductor
- Spin polarization in Lateral two-dimensional Heterostructures
- Testbeds for Transition Metal Dichalcogenide Photonics: Efficacy of Light Emission Enhancement in Monomer vs. Dimer Nanoscale Antennae
- Enhancement of valley polarization at high photoexcited densities in MoS2 monolayers
- Spin and valley filter based on two-dimensional WSe heterostructures
- How the dynamic of photo-induced gate screening complicates the investigation of valley physics in 2D materials