Strain tuning of optical emission energy and polarization in monolayer and bilayer MoS 2 - INSA Toulouse - Institut National des Sciences Appliquées de Toulouse Access content directly
Journal Articles Physical Review B: Condensed Matter and Materials Physics (1998-2015) Year : 2013

Strain tuning of optical emission energy and polarization in monolayer and bilayer MoS 2

Abstract

We use micro-Raman and photoluminescence (PL) spectroscopy at 300 K to investigate the influence of uniaxial tensile strain on the vibrational and optoelectronic properties of monolayer and bilayer MoS2 on a flexible substrate. The initially degenerate E′ monolayer Raman mode is split into a doublet as a direct consequence of the strain applied to MoS2 through Van der Waals coupling at the sample-substrate interface. We observe a strong shift of the direct band gap of 48 meV/(% of strain) for the monolayer and 46 meV/% for the bilayer, whose indirect gap shifts by 86 meV/%. We find a strong decrease of the PL polarization linked to optical valley initialization for both monolayer and bilayer samples, indicating that scattering to the spin-degenerate Γ valley plays a key role.
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Dates and versions

hal-02050742 , version 1 (27-02-2019)

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  • HAL Id : hal-02050742 , version 1

Cite

C. Zhu, Gang Wang, B. Liu, Xavier Marie, X. Qiao, et al.. Strain tuning of optical emission energy and polarization in monolayer and bilayer MoS 2. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2013, 88 (12). ⟨hal-02050742⟩
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