Download Electron Mobility in Graphene as a function of Strain

Bachelor Thesis / SS 2015:
Electron Mobility in Graphene as a function of Strain
The figure visualizes a local strain fluctuation
in a graphene sheet. Apart from the out-ofplane fluctuation, there are also in-plane
fluctuations present.
Since its discovery in 2004, graphene became a very promising candidate for future applications in
Nano Electro-Mechanical Systems (NEMS). As graphene is only one atomic layer thick, its electrical
properties are very sensitive to mechanical disturbances. It is therefore thought that so-called local
strain fluctuations in a graphene sheet limit the electron mobility, i.e. a number that quantifies how
good electrons can propagate through a conducting material.
One can think of local strain fluctuations as wrinkles in a piece of paper. Similarly to wrinkles in a
sheet of paper, one can try to reduce these local strain fluctuations by stretching the graphene.
However, first principle calculations show that although the out-of-plane fluctuations (wrinkles) may
be reduced, but the in-plane strain fluctuations actually increase.
The goal of this project is to calculate the scattering cross section for electrons to scatter on these
strain fluctuations and try to link it with the electron mobility. For this, we will use the atom positions
from the first principle calculations as a function of global strain.
The student will learn to do simulations and analyses with Matlab and gain a good understanding of
the transport properties of graphene.
Contact: Gerard Verbiest ([email protected])