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Abstract: Semiconducting molybdenum ditelluride (2H‐MoTe2), a fast‐emerging 2D material with an appropriate band gap and decent carrier mobility, is configured as field‐effect transistors and is the focus of substantial research interest, showing hole‐dominated ambipolar characteristics. Here, carrier modulation of ambipolar few‐layer MoTe2 transistors is demonstrated utilizing magnesium oxide (MgO) surface charge transfer doping. By carefully adjusting the thickness of MgO film and the number of MoTe2 layers, the carrier polarity of MoTe2 transistors from p‐type to n‐type can be reversely controlled. The electron mobility of MoTe2 is significantly enhanced from 0.1 to 20 cm2 V−1 s−1 after 37 nm MgO film doping, indicating a greatly improved electron transport. The effective carrier modulation enables to achieve high‐performance complementary inverters with high DC gain of >25 and photodetectors based on few‐layer MoTe2 flakes. The results present an important advance toward the realization of electronic and optoelectronic devices based on 2D transition‐metal dichalcogenide semiconductors. [ABSTRACT FROM AUTHOR]

Van der Waals epitaxy growth of two-dimensional materials promise controllable fabrication of novel artificial heterostructures. Here, we report molecular beam epitaxy growth of continuous molybdenum ditelluride (MoTe 2 ) films on graphene substrates with good stoichiometry in both 2H and 1T′ phases. Post-growth annealing reveal phase transition suppressed in Te-rich atmosphere, through in-situ scanning tunneling microscopy/spectroscopy and X-ray photoelectron spectroscopy. Our results suggest a new route to fabricate atomically ultrathin MoTe 2 lateral heterophase homojunctions, showing potential applications in future lateral thin-film transistors. [ABSTRACT FROM AUTHOR]

Abstract: Electron-beam mediated substitutional doping of monolayer MoS2 was recently demonstrated, opening a new way to modify its properties. Using first-principles calculations, the structural, electronic and magnetic properties of monolayer MoS2 doped with nonmetal and transition-metal atoms are investigated. All dopants are strongly bound to the structures, inducing interesting magnetic behaviors. While all H, B, N and F-doped monolayers have magnetic moment of 1.0 , V, Cr, Mn, Fe and Co-doped ones attain 1.0, 4.0, 3.0, 3.0 and 1.0 , respectively. Additionally, MoS2 undergoes transition from semiconductor to half-metal in the presence of H, B or Cr doping. [Copyright &y& Elsevier]

Abstract: We present our study on elastic constants and electronic structures of two-dimensional monolayer MoS2 under elastic strain using the first-principles calculations. The in-plane stiffness and Poissonʼs ratio calculated in the harmonic elastic strain range are found to be 123 N/m and 0.25, indicating that monolayer MoS2 is much softer than graphene. With the uniform strain applied, it is shown that the band gap of monolayer MoS2 undergoes a descent trend as strain increasing. Simultaneously, it is accompanied by two characteristic transitions, namely, direct-to-indirect transition at strain of 0.01 and semiconductor-to-metal transition at strain of 0.10. Furthermore, the effective mass of carriers is also modulated by the applied strain. [Copyright &y& Elsevier]