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Tuning Electronic Transport in WSe2-Graphene

  • Yu-Chuan Lin
Chapter
Part of the Springer Theses book series (Springer Theses)

Abstract

In many atomically thin photovoltaic devices, field effect transistors, and tunneling diodes, 2D TMDC have been used as a semiconducting layer in tandem with graphene and many other substrates. It is necessary to achieve efficient charge transport across WSe2-graphene, which creates a semiconductor to semimetal junction. In such cases, the band alignment engineering is required to ensure a low-resistance, ohmic contact. In previous chapter, we cover preparation and fundamental properties of WSe2-graphene. In this chapter, we investigate the impact of graphene properties on the transport at the interface of WSe2-graphene. Electrical transport measurements reveal a change in resistance between WSe2 and fully hydrogenated epitaxial graphene (EGFH) compared to WSe2 grown on partially hydrogenated epitaxial graphene (EGPH). Using low-energy electron microscopy and reflectivity (LEEM/LEER) on these samples, we extract the work function difference between the WSe2 and graphene and employ a charge transfer model to determine the WSe2 carrier density in both cases. The results here indicate that WSe2-EGFH displays nearly ohmic behavior at small biases due to a large hole density in the WSe2, whereas WSe2-EGPH forms a Schottky barrier junction.

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Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  • Yu-Chuan Lin
    • 1
  1. 1.Center for Nanophase Materials SciencesOak Ridge National LaboratoryOak RidgeUSA

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