Roll-to-Roll Production of Layer-Controlled Molybdenum Disulfide: A Platform for 2D Semiconductor-Based Industrial Applications.

A facile methodology for the large-scale production of layer-controlled MoS ₂ layers on an inexpensive substrate involving a simple coating of single source precursor with subsequent roll-to-roll-based thermal decomposition is developed. The resulting 50 cm long MoS ₂ layers synthesized on Ni foils possess excellent long-range uniformity and optimum stoichiometry. Moreover, this methodology is promising because it enables simple control of the number of MoS ₂ layers by simply adjusting the concentration of (NH ₄ ) ₂ MoS ₄ . Additionally, the capability of the MoS ₂ for practical applications in electronic/optoelectronic devices and catalysts for hydrogen evolution reaction is verified. The MoS ₂ -based field effect transistors exhibit unipolar n-channel transistor behavior with electron mobility of 0.6 cm ² V ^-1 s ^-1 and an on-off ratio of ≈10³. The MoS ₂ -based visible-light photodetectors are fabricated in order to evaluate their photoelectrical properties, obtaining an 100% yield for active devices with significant photocurrents and extracted photoresponsivity of ≈22 mA W ^-1 . Moreover, the MoS ₂ layers on Ni foils exhibit applicable catalytic activity with observed overpotential of ≈165 mV and a Tafel slope of 133 mV dec ^-1 . Based on these results, it is envisaged that the cost-effective methodology will trigger actual industrial applications, as well as novel research related to 2D semiconductor-based multifaceted applications.
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