Advanced CVD technology for large area graphene and 2D transition metal di-chalcogenides

Graphene, one of the most important two dimensional (2D) materials, has been attracting increasing interest and new applications in nano-scale electronic and photonic applications through the unprecedented electronic and optical properties it offers. However, the zero bandgap of graphene has restricted its use in some optoelectronic applications. Recently, transition metal dichalcogenides (TMDCs), two-dimensional layered materials, such as MoS2, MoSe2, WS2 and WSe2 have become a noteworthy complimentary material to graphene sharing many of its properties. They may however offer properties that are unattainable in graphene since TMDCs offer tuneability allowing a bandgap transition from indirect to direct with the single layer. This has led to use of TMDCs in applications such as transistors, photodetectors and electroluminescent devices. Chemical vapour deposition (CVD) technology has the advantage of offering conformal, scalable, and controllable thin film growth on a variety of different substrates. Here we report our recent CVD technology development in graphene and 2D TMDCs materials, in particularly MoS2. To date we have achieved 40 by 120 mm single and few layer MoS2 using this scalable CVD process