Defence in the field of engineering physics, Kaustuv Banerjee, M.Sc.(Tech.)
The title of the dissertation is: Molecular self-assembly on graphene – structure and effects
Kaustuv Banerjee, M. Sc. (Tech.), will defend the dissertation "Molecular self-assembly on graphene – structure and effects" on 15 September 2017 at 12 noon in Aalto University School of Science, lecture hall U1 (U154), Otakaari 1, Espoo. In this dissertation, surface confined self-assembly of organic molecules on graphene is investigated. While the structure and electronic properties of the molecules on graphene is probed using scanning tunnelling microscopy, their effect on the electronic properties of graphene is studied by means of transport experiments on graphene field-effect transistors.
The wonder material graphene, a single-atom layer thick layer of graphite, can be potentially used to make ultra-fast and energy-efficient electronic circuits. However, this would require modification of its electronic properties without sacrificing its desirable elements. Single layers of organic molecules adsorbed on graphene is a facile method to achieve this. Under suitable conditions, the molecules can spontaneously assemble into periodic structures and can be utilised in achieving the holy-grail of graphene electronics – opening a gap in its band-structure.
In this work, molecular self-assembly on graphene is experimentally investigated with scanning tunnelling microscope, an instrument that enables us to visualise individual atoms and molecules on surfaces. The structure and electronic properties of several organic molecules adsorbed on graphene is studied in this manner. Finally, the effect of these molecules on the electronic properties of graphene is studied by observing how the electrical field dependent resistance across an ultra-clean flake of graphene changes on molecular adsorption. The results demonstrate graphene to be a unique substrate for molecular assembly and point to fruitful directions for using molecules to tune the amount of charge carriers in graphene.
Dissertation release (pdf)
Opponent: Associate Professor Sabine Maier, University Erlangen-Nürnberg, Germany
Custos: Professor Peter Liljeroth, Aalto University School of Science, Department of Applied Physics
Electronic dissertation: http://urn.fi/URN:ISBN:978-952-60-7578-5