Mechanical and electrical properties of functionalized graphene nanoribbon

: A study of reactive molecular dynamic simulation and

density functional tight-binding theory

Figure: https://www.sciencealert.com/graphene 1[1]Ref: Esmaeil Zaminpayma, Payman Nayebi. (2015).Journal Physica B: Condensed Matter V.459 p.29-35

OutlineIntroduction

Conclusion

Method and results

What is graphene and graphene nanoribbon?stress-strain.Program

Mechanical properties.Electrical properties.

2

What is graphene?

Graphene is a single layer of carbon atoms that arranged in hexagonal. Graphenehas a variety properties such as electrical conductivity, strength, flexible andlightweight.

Graphene was discovered by Andre Geimand Konstantin Novoselov in 2004. Theywon Nobel Prize in physics in 2010.

3

Figure: www.understandingnano.com/what-is-graphene.html

Graphite Carbon nanotubeBuckyballSource&Figure: https://www.sciencealert.com/graphene

Graphene nanoribbon (GNR)

Armchair graphene nanoribbons (AGNRs)

Zigzag graphene nanoribbons (ZGNRs)are metallic

are metallic and semiconductor

Zigzag edge

Armchair edge4Figure: https://commons.m.wikimedia.org/wiki/File:Graphene_nanoribbons.png

Stress-strain Stress

is force per unit area.

Young’s modulus is slope of stress-strain curve.5

Strain

is material change shape(Deformation) when there area external force.

Elastic Deformation or Elastic Strain.Plastic Deformation or Plastic Strain.

Source&Figure: https://www.engineeringtoolbox.com/stress-strain-d_950

Program packgageLAMMPS

Molecular Dynamics SimulatorDensity Functional Tight-Binding

(DFTB+)

https://www.lammps.org/ https://dftbplus.org/6

Nanoribbon length = 20 AํNanoribbon width = 18 Aํ

7

d) Phenyl

a) amino

b) methyl

c) hydroxyl

Structure of nanoribbon with function group

Mechanical properties

Method

Increase the size on the lenght side. It is like pulling

Calculates the stress-strain curve at 100K.

Calculates the Young's modulus at 100K, 200K, and300K.

8

Stress-strain curve at 100K

Table: Young's modulus of the functionalized nanoribbon as a function of temperature.9

K

Ref: [1]Esmaeil Zaminpayma, Payman Nayebi. (2015). Journal Physica B: Condensed Matter V.459 p.29-35

nanoribbon was -206Kcal/mol.nanoribbon with CH group was reduced to -190Kcal/mol.

The per-atom potential energy

The functional group will decrease the potential energy of thenanoribbon.

Functional groups form bonds with nanoribbons. and theformation of new bonds broke the old bonds of thenanoribbons.

10

3

Ref: Esmaeil Zaminpayma, Payman Nayebi. (2015). Journal Physica B: Condensed Matter V.459 p.29-35

Electrical propertiesMethod

Calculate the current with this formula. Used voltagefrom 0V to 2V in 0.25V increments at 0% and 5% strain.

11

The current–voltage (I–V) curves at 0% strain.

Current and voltage graphs are nonlinear model, but ranges below 0.75Vcould be consider linear model forfind resistance by using Ohm's law.

The resistances -CH = 26.175 kΩ -C H = 29.60 kΩ -NH = 38.23 kΩ -OH = 43.87 kΩ

12

3

6 5

2

Ref: [1]Esmaeil Zaminpayma, Payman Nayebi. (2015). Journal Physica B: Condensed Matter V.459 p.29-35

Area under The transmission probability graph.CH > C H > NH > OH > nanoribbon

The transmission probability at 1V voltage.

Transmission probability

133 6 5 2

Ref: [1]Esmaeil Zaminpayma, Payman Nayebi. (2015). Journal Physica B: Condensed Matter V.459 p.29-35

The current–voltage (I–V) curves at 0% strain. The current–voltage (I–V) curves at 5% strain.

14Ref: [1]Esmaeil Zaminpayma, Payman Nayebi. (2015). Journal Physica B: Condensed Matter V.459 p.29-35

The RDFs of unfunctionalized nanoribbon at 0% and 5% strain.

The radial distribution function (RDF)

At 5% strain increase the lenght and decrease the current.

15Ref: [1]Esmaeil Zaminpayma, Payman Nayebi. (2015). Journal Physica B: Condensed Matter V.459 p.29-35

Conclusion

Adding a functional group to a nanoribbon decreases themechanical properties.Increasing temperature strength of nanoribbon and functiongroup decrease.

16

Mechanical properties

Adding a functional group to a nanoribbon increases the electricalpropertiesAt 5% strain the curent is less than at 0% strain.

Electrical properties

The current–voltage (I–V) curves at 0% strain. The current–voltage (I–V) curves at 5% strain.

17

18

Reference[1] Esmaeil Zaminpayma, Payman Nayebi. (2015). Mechanical andelectrical properties of functionalized graphene nanoribbon: Astudy of reactive molecular dynamic simulation and densityfunctional tight-binding theory, Physics B: Condensed Matter (15February 2015): 29-35. https://doi.org/10.1016/j.physb.2014.11.015

https://www.sciencealert.com/graphene

https://www.engineeringtoolbox.com/stress-strain-d_950

https://commons.m.wikimedia.org/wiki/File:Graphene_nanoribbons.png

Thank youNiramai Chirapraphusak

6205130

19