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Ph.D.
(Science)
INVESTIGATIONS ON TRANSPORT PROPERTIES OF
GRAPHENE BASED BILAYER SYSTEMS

Ph.D. Scholar : Vyas Harsh Tusharkumar
Research Supervisor : Dr. Digish K. Patel

Regi. No.: 18276471002
Abstract :
Graphene, a one atom thick carbon sheet, has provided an immense boost up and new
dimension to material science and nanotechnology due to its eminent features. The latest
advances in graphene research have sparked the development of exciting
nanoelectronics gadgets comprised of atomically thin materials and graphene. A good
example is Graphene based Double Layer System(GDLS). In view of that I carried
theoretical investigations on transport properties of graphene based bilayer systems like
Monolayer Graphene Double Layer System (MLGDL), Bilayer Graphene Double Layer
System (BLGDL) and Graphene based hybrid systems. In some cases, it has been
observed that the theoretical model does not match the experimental model, which
indicates some missing parameters and may be defects present in the crystal. To check
this effect in Graphene heterostructure, I have primarily investigated two types of
scatterers: short range scattering and long range scattering in presence some parameter
like carrier concentration, mismatch in dielectric, interlayer distance and temperature
effect. Screening effect has been carried out within standard approximation called
Random Phase Approximation (RPA). Conductivity has been calculated within the
framework of Boltzmann Transport theory.

This thesis is organized into five chapters. Chapter 1 is a graphene introduction with
properties and applications. Chapter 1 also introduces the methods, like Random Phase
Approximation (RPA), that will describe the screening and Boltzmann transport theory
used to calculate the electrical conductivity of graphene systems. Study on previously
reported work and objective of the thesis are reported in Chapter 1. The electronic
transport properties of MLGDL, BLGDL, and Graphene based hybrid systems at zero as
well as finite temperature are covered in Chapters 2, 3, and 4, respectively. Our primary
research has focused on the effects of carrier concentration, interlayer distance, and the
dielectric environment on these systems. Finally, in Chapter 5, the conclusions of all the
chapters are summarized and planning of future work is discussed.

Keywords: Graphene based double layer system, Monolayer Graphene Double Layer
System, Bilayer Graphene Double Layer System, Short Range.

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