Publications by authors named "Haolei Qian"

Monolayer molybdenum disulfide (MoS), consisting of covalently bonded S-Mo-S sandwiched layers, has high carrier mobility and a direct bandgap of 1.8 eV, offering properties for electronic and optoelectronic devices with high performance. Usually, it is essential to modulate the carrier concentrations and conductivities of monolayer MoS for practical applications.

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ZnO nanorod arrays were synthesized by hydrothermal method with two different zinc salts as precursors: zinc acetate and zinc nitrate. Different anions in solution distinctly influence the intrinsic defects in ZnO nanostructures, resulting in different photoluminescence properties. The defects induced by precursors were systematically studied by photoluminescence spectroscopy, X-ray photoelectron spectrometer and electron paramagnetic resonance.

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We report on the feasible control of the threshold voltage (V th) in ultra-thin ZnO nanobelt FETs by using substoichiometric molybdenum trioxide (MoO x , x < 3) either as a modification layer on the surface of ZnO nanobelts or as electrodes instead of the widely used Ti/Au. ZnO nanobelt FETs using Ti/Au as the electrodes usually exhibit a negative threshold voltage, indicating n-channel depletion mode behavior, whereas ZnO FETs with MoO x /Au electrodes instead of Ti/Au show a positive shift of threshold voltage, exhibiting an n-channel type enhancement mode, which can be explained by a high Schottky barrier created at the interface of MoO x and the ZnO channel. In contrast, the decoration on the surface of ZnO channel by MoO x significantly increases the zero-bias conductivity and electron carrier concentration, and then negatively shifts the threshold voltage.

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