Chakraborty, Biswanath and Bera, Achintya and Muthu, DVS and Bhowmick, Somnath and Waghmare, UV and Sood, AK (2012) Symmetry-dependent phonon renormalization in monolayer MoS2 transistor. In: Physical Review B, 85 (16).
PhysRevB.85.161403.pdf - Published Version
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A strong electron-phonon interaction which limits the electronic mobility of semiconductors can also have significant effects on phonon frequencies. The latter is the key to the use of Raman spectroscopy for nondestructive characterization of doping in graphene-based devices. Using in situ Raman scattering from a single-layer MoS2 electrochemically top-gated field-effect transistor (FET), we show softening and broadening of the A(1g) phonon with electron doping, whereas the other Raman-active E-2g(1) mode remains essentially inert. Confirming these results with first-principles density functional theory based calculations, we use group theoretical arguments to explain why the A(1g) mode specifically exhibits a strong sensitivity to electron doping. Our work opens up the use of Raman spectroscopy in probing the level of doping in single-layer MoS2-based FETs, which have a high on-off ratio and are of technological significance.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article is belongs to The American Physical Society.|
|Department/Centre:||Division of Physical & Mathematical Sciences > Physics|
|Date Deposited:||23 Aug 2012 07:40|
|Last Modified:||23 Aug 2012 07:40|
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