Comprehensive tunneling spectroscopy of quasifreestanding MoS2 on graphene on Ir(111)

Article

关键词: SINGLE-LAYER MOS2;    ELECTRONIC-STRUCTURE;    GROWTH;    STATES;    GAP;   

DOI  :  10.1103/PhysRevB.99.115434

来源: SCIE

【 摘 要 】

We apply scanning tunneling spectroscopy to determine the band gaps of mono-, bi-, and trilayer MoS2 grown on a graphene single crystal on Ir(111). Besides the typical scanning tunneling spectroscopy at constant height, we employ two additional spectroscopic methods giving extra sensitivity and qualitative insight into the k vector of the tunneling electrons. Employing this comprehensive set of spectroscopic methods in tandem, we deduce a band gap of 2.53 +/- 0.08 eV for the monolayer. This is close to the predicted values for freestanding MoS2 and larger than is measured for MoS2 on other substrates. Through precise analysis of the comprehensive tunneling spectroscopy we also identify critical point energies in the mono- and bilayer MoS2 band structures. These compare well with their calculated freestanding equivalents, evidencing the graphene/Ir(111) substrate as an excellent environment upon which to study the many celebrated electronic phenomena of monolayer MoS2 and similar materials. Additionally, this investigation serves to expand the fledgling field of the comprehensive tunneling spectroscopy technique itself.

【 授权许可】

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