Tej B. Limbu
Department of Physics
University of Puerto Rico, San Juan, PR
Layer number and grain size controlled growth of graphene and study on optical, electrical, and thermal properties
Location: EB1 Room 3003
Friday, July 14th 2017 - 10:30 am
Thermal chemical vapor deposition (TCVD) of methane on copper is the most common technique of high quality and large area graphene growth at present days. However, graphene growth by TCVD is likely to be limited to monolayer owing to the surface mediated self-limiting growth process on copper, and hence it is difficult to obtain large area bilayer and multilayer graphene. Here, we report layer number controlled growth of high quality and large area polycrystalline graphene on copper foil in the hot filament chemical vapor deposition (HFCVD). We also show that grain size controlled graphene growth can be performed facilely in this reactor, which is of technological importance for tailoring the properties of graphene. We will discuss optical and electrical properties of chemically doped twisted bilayer graphene. Effect of grain boundaries on thermal conductivity of nanocrystalline twisted bilayer graphene has also been studied, and the results show that the degradation of thermal conductivity due to grain boundaries is smaller in bilayer than in monolayer graphene.