Vapor-based Synthesis

Our group is looking at vapor based approaches, such as chemical vapor deposition (CVD), to synthesize 2D layered materials. Challenges in this work include addressing issues of grain size and crystallinity, controlling layer thickness and finding ways to controllably dope layers over large areas, which are of paramount importance for enabling practical applications to emerge from such vapor synthesized 2D layered materials.  We use table-top tube furnaces for our research (MTI) where an assortment of gasses can be used during high-temperature growth of our nanomaterials.  

Furnace for Nanocarbon synthesis (graphene and other nanocarbons)

 

Furnaces for Sulphide and Selenide synthesis

 

Our current materials of interest for CVD synthesis are MoS2 and WSe2, in addition to graphene. We have successfully grown monolayer MoS2 and WSe2 which exhibit good crystalline quality. The materials are typically characterized using Raman Spectroscopy, Atomic Force Microscopy and Scanning Electron Microscopy.  The crystallites can then be transferred onto other types of substrates and devices can then be formed using conventional lithography or e-beam lithography to understand the material and/or device properties.

VBS 5 Flexible DeviceVBS 7

Triangular crystallites of MoS2 are shown, along with the Raman Spectra obtained for MoS2