Tuning electron transport in metal films and graphene with organic monolayers

Research output: ThesisPhD Thesis - Research UT, graduation UT

78 Downloads (Pure)

Abstract

Introducing organic molecules into electronic devices has attracted significant research interest due to its promise in both technological development and fundamental research. Organic molecules are used for many purposes such as uniform and patterned doping of silicon with donor atoms and the modification of the electronic properties of graphene. However, they were not used for magnetic doping of metals before. In this thesis, we used transition metal complexes as magnetic doping agents, which led to a novel molecular fabrication method for inserting isolated localized magnetic moments in a gold film with tunable density and with high reproducibility. Our molecular spin doping technique can be used for the investigation of very important physical phenomena such as the Kondo effect, RKKY interaction which can lead to further understanding of impurity-electron, impurity-impurity interactions. It was also found that capping the monolayers with a thin layer of gold by e-beam evaporation increases the observed Kondo effect slightly, whereas Au capping by magnetron sputtering enhances the effect significantly. The results implied that it is possible to change the strength of impurity-host electron interactions in such systems, by tuning the deposition parameters of capping Au layers. Graphene has attracted significant research interest due to its unique band structure. In this thesis, electronic properties of graphene were modified by inserting molecular complexes between graphene sheet and SiO2/Si substrates. It was observed that the molecular complexes induced p-type doping of the graphene, which resulted in a hysteresis effect. It was shown that our molecular-layer/graphene system can be used to make memory devices exhibiting up to 4 different resistance states.
Original languageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • van der Wiel, Wilfred G., Supervisor
Thesis sponsors
Award date4 Dec 2014
Place of PublicationEnschede
Publisher
Print ISBNs9789036538022
DOIs
Publication statusPublished - 4 Dec 2014

Fingerprint

Dive into the research topics of 'Tuning electron transport in metal films and graphene with organic monolayers'. Together they form a unique fingerprint.

Cite this