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

Abstract 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.