Scanning probe microscopy of adsorbed molecules on boron nitride and graphene monolayers

Pollard, Andrew J. (2010) Scanning probe microscopy of adsorbed molecules on boron nitride and graphene monolayers. PhD thesis, University of Nottingham.

[img]
Preview
PDF (Andrew J. Pollard Thesis 2010)
13Mb

Abstract

In this thesis, a study of a range of functional surfaces formed in ultra-high vacuum (UHV) conditions using primarily scanning probe microscopy is presented. The construction of a combined scanning tunnelling and atomic force microscope, and the experiments performed using this instrument, are also detailed.

Boron nitride and graphene monolayers were formed on rhodium thin films in UHV and investigated with in-situ and ex-situ (ambient conditions) scanning tunnelling microscopy. Simultaneous scanning tunnelling and atomic force microscopy images were also produced for the graphene monolayers. X-ray photoelectron spectroscopy and diffraction results for graphene monolayers on Rh(111) surfaces, as well as low energy electron diffraction data, are also included.

The novel formation of monolayer and few-layer graphene on nickel thin films is also described. Graphene layers were detached from these nickel thin films and isolated on other substrates. The results of characterisation experiments using scanning probe microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electron microscopy techniques are detailed. Graphene layers with approximately 75% monolayer graphene coverage and an increased electronic quality, when compared to many other methods of graphene production, were revealed.

Different organic molecules were adsorbed on both the boron nitride and graphene monolayers formed on rhodium thin films in UHV conditions. Perylene tetracarboxylic diimide (PTCDI) and di(propylthio)-PTCDI molecules were investigated on these surfaces and compared with the adsorption of PTCDI on a graphite surface. Furthermore, dibutyl-coronene tetra-carboxylic diimide was deposited on the graphene (on rhodium) surface, in UHV. Although the boron nitride and graphene surfaces were similar, it was discovered that very contrasting molecular formations were formed on the dierent surfaces. The positioning of these nanostructures was determined by the Moire superstructure formed due to the mismatch between the monolayers and the Rh(111) surface. Additionally, different hydrogen-bonded molecular junctions were formed depending on the length of the side chains of the adsorbed organic molecules.

Item Type:Thesis (PhD)
Supervisors:Beton, P.H.
Uncontrolled Keywords:SPM STM AFM Graphene Boron Nitride
Faculties/Schools:UK Campuses > Faculty of Science > School of Physics and Astronomy
ID Code:2121
Deposited By:Dr Andrew Pollard
Deposited On:02 Dec 2011 13:20
Last Modified:02 Dec 2011 13:20

Archive Staff Only: item control page