Trickle Flow Aided Atomic Layer Deposition (ALD) Strategy for Ultrathin Molybdenum Disulfide (MoS2) Synthesis
journal contributionposted on 20.09.2019 by Junjie Yang, Lei Liu
Any type of content formally published in an academic journal, usually following a peer-review process.
The synthesis of large-area and high-quality two-dimensional (2D) MoS2 is undoubtedly a significant challenge till now. In this work, an effective strategy for achieving 2D MoS2 with enlarged grain size by Ni-foam-based trickle flow atomic layer deposition (ALD) was suggested, by which MoS2 grain sizes up to 420 nm (monolayer sample) and 400 nm (five-layer sample) were obtained under the covering of 1 mm-thick Ni foam with a 2 mm gap from the substrate at 460 °C. In terms of specific ALD experiments, the Ni foam with a certain thickness placed on top of the substrate made the original precursor flow into a trickle-fluidization source flow, which decreased the nucleation density effectively. Thus, MoS2 with enlarged grain sizes were obtained based on the typical ALD mechanism of large-scale vertical growth under the action of steric hindrance after a planar parallel growth around the crystal nucleus. In addition, the Ni foam also achieved a stable temperature field by enhancing the heat transfer around the substrate and thus improved its crystallinity.