This document provides an introduction to a thesis investigating the thermal conductivity of silicene nano-ribbons. Silicene is a two-dimensional allotrope of silicon that forms a hexagonal honeycomb structure similar to graphene. Using scanning tunneling microscopes, silicene nano-ribbons can be self-assembled and studied. The objectives of the thesis are to examine how the thermal conductivity of silicene nano-ribbons is affected by length, isotopic doping, applied tensile strains, chirality, and the addition of hydrogen atoms. Atomistix Virtual Nano Lab software will be used to simulate and analyze the physical properties at the nano-scale through density functional theory calculations.

1. Synopsis of thesis Entitled on
INVESTIGATION OF Thermal
CONDUCTIVITY IN SILICENE
NANO-RIBBON
SUBMITTED BY:
GAGANDEEP SINGH RANDHAWA
M.TECH 4th SEM.
2014ECB1006

2. INTRODUCTION TO SILICENE
NANO-RIBBONS:
 Study of nanomaterial took off some 40 years ago with the design
of so-called quasi-two-dimensional.
 In 2004, the study of exact 2D solids became a renewed focus.
 Graphene was isolated from graphite and its many fascinating
properties were demonstrated.
 Silicene is a two-dimensional allotrope of silicon.
 Has a hexagonal honeycomb structure similar to that of graphene.

3. CONTD.
 Using a scanning tunneling microscope they self-
assembled silicene Nano ribbons can be studied.
 Density functional theory (DFT) calculations showed that silicon
atoms tend to form such honeycomb structures on silver.
 In 2015, a silicene field-effect transistor made its debut.
 It opened up new opportunities for two-dimensional silicon for
various fundamental science studies and electronic applications.

4. ATOMIC STRUCTURE OF SILICENE
NANO-RIBBONS:
 Primary method for growing silicene is on silver substrate.
 On Ag (111), silicene forms a continuous sheet, with at least three
distinct ordered phases, depending on the deposition conditions.
 On the Ag (110) surface, one-dimensional silicene Nano ribbons
(NRs) can be grown.
 Isolated NRs show a low reactivity to molecular oxygen.
 Oxidation occurs only at the Si NRs terminations.

5. CONTD.
Figure: STM image of silicene NRs grown at 230◦ C on a Ag
(110) surface (12.5x12.5 nm2, V = -80 mV, I = 2.2 nA)

6. PROBLEM FORMULATION:
 Despite extensive study on the electric property of silicene, little
research has been devoted to the thermal (phonon) transport of
silicene so far.
 Heat conduction can occur in two ways namely particle collision and
lattice vibration.
 In Silicene Nano ribbons thermal transfer occurs by lattice vibration.
 The atoms or molecules are bound to each other by a series of bonds
acting like springs.
 The interconnected bonds will form a specific lattice structure.

7. OBJECTIVES:
The main objective of my thesis is to examine the behavior of the
thermal conductivity of silicene Nano ribbons:
 At different lengths.
 At different isotopic doping.
 At different applied tensile strains.
 At different chiralities.
 The effect of the addition of hydrogen atoms.

8. TOOL USED:
 Atomistix Virtual Nano Lab (VNL) is a commercial point-and-
click software for simulation and analysis of physical and chemical
properties of Nano scale devices.
 Developed and sold commercially by Quantum Wise A/S.
 Provides a user-friendly approach to atomic-scale modeling.
 Allows the user to design Nano systems, to set up and execute
numerical calculations, and to visualize the results.
 Combines density functional theory and non-equilibrium Green's
functions to ab initio electronic-structure and transport calculations.

9. THANK
YOU