摘要(英) |
Recently, the development of two-dimensional materials has been accelerated. Among the two-dimensional materials, transition metal dichalocogenides(TMDs) are regarded as the most forward-looking ones, and of which molybdenum disulfide(MoS2) develops the fastest. For MoS2, the performances in electronics of its applications are limited by metal contacts, which may cause strains, chemical reactions, or even damages to MoS2. Moreover, metal contacts will cause Fermi-level pinning limiting the electrical properties. In order to observe the effects after depositing metals, we transfer MoS2 to silicon oxide(SiO2) using a polymethyl methacrylate(PMMA)-assisted wet transfer method, and then deposit metals on the monolayer MoS2 by the electron beam evaporation system and the thermal evaporation system. We analyze the properties of samples by Raman spectroscopy, X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD), scanning electron microscope(SEM) and transmission electron microscopy(TEM). We uncover that Ti, Ni, Ag and Au cause different levels of damage to MoS2; In, Sn and Bi only produce a small amount of strain, so In, Sn, Bi are more suitable as contact metals. In addition, Bi has different lattice orientations on MoS2. |
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