Recently graphene has attracted immense interest for wide range of applications in nanotechnology. Replacing the usual SiO2/Si(++) substrate with substrate of high dielectric constant for making graphene FET will open up various possibilities of exploring new physics as well as improving device quality with high doping. One of such substrate with high dielectric constant is Strontium Titanate (SrTiO3) [STO]. At room temperature, its dielectric Constant εr = 300 and it increases with decreasing temperatures (upto order of 104 at cryogenic temperature). We are studying the behaviour of Graphene FET on STO at low temperatures to understand the effect of STO on Graphene band structure.
Hetero-structures based on 2-D materials like graphene, Molybdenum disulfide (MoS2) have started a new paradigm in 2-D electronics. In a graphene contacted MoS2 FET, the absence of dangling bonds at the interface of Graphene and MoS2 reduces the appearance of charge traps improving the quality of contact. Also, the work function of graphene can be tuned using back gate voltage to get high quality low resistive contact on MoS2. We are studying the behaviour of Graphene/MoS2 interface with different device geometry.