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Journal articles
Bandgap inhomogeneity of MoS$_2$ monolayer on epitaxial graphene bilayer in van der Waals p-n junction
Abstract : Atomically thin MoS$_2$/graphene vertical heterostructures are promising candidates for nanoelectronic and optoelectronic technologies.In this work, we studied the optical and electronic properties of n doped single layer MoS$_2$ on p doped bilayer graphene vdW heterostructures. We demonstrate a non-uniform strain between two different orientation angles of MoS$_2$ monolayer on top of epitaxial bilayer gra-phene. A significant downshift of the E$^1$$_{2_g}$ mode, a slight downshift of the A$_{1_g}$ mode, and photo-luminescence shift and quenching are observed between two MoS$_2$ monolayers differently oriented with respect to graphene; This could be mostly attributed to the strain-induced transition from direct to indirect bandgap in monolayer MoS$_2$. Moreover, our theoretical calculations about differently-strained MoS$_2$ monolayers are in a perfect accordance with the experimentally observed behavior of differently-oriented MoS$_2$ flakes on epitaxial bilayer graphene. Hence, our results show that strain-induced bandgap engineering of single layered MoS$_2$ is dependent on the orientation angle between stacked layers. These findings could be an interesting novel way to take advantage of the possibilities of MoS$_2$ and deeply exploit the capabilities of MoS$_2$/graphene van der Waals heterostructures.
https://hal-cea.archives-ouvertes.fr/cea-01490885
Contributor : Dominique Girard Connect in order to contact the contributor
Submitted on : Thursday, March 16, 2017 - 10:30:55 AM
Last modification on : Monday, December 13, 2021 - 9:16:32 AM
Long-term archiving on: : Saturday, June 17, 2017 - 1:16:37 PM
Contributor : Dominique Girard Connect in order to contact the contributor
Submitted on : Thursday, March 16, 2017 - 10:30:55 AM
Last modification on : Monday, December 13, 2021 - 9:16:32 AM
Long-term archiving on: : Saturday, June 17, 2017 - 1:16:37 PM
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