Graphene/BN/heterostructures and devices
Lead Research Organisation:
University of Nottingham
Department Name: Sch of Physics & Astronomy
Abstract
The focus of study will be heterostructures formed by boron nitride and graphene which are grown using a newly installed molecular beam epitaxy system. The PhD student will focus on the understanding of graphene growth on a variety of substrates including epitaxial boron nitride. The structures will be analogues of recent G/BN resonant tunnelling diode prepared by exfoliation and the student will develop new techniques for the transfer and contacting of samples and later focus on electrical measurements using various scanning probe instruments as well as using structures in the form of devices with external wiring. The devices will be investigated using electrical measurements, including at low temperature and in the presence of high magnetic fields, and, where relevant, electroluminescence spectroscopy.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N50970X/1 | 01/10/2016 | 30/09/2021 | |||
| 1794546 | Studentship | EP/N50970X/1 | 01/10/2016 | 26/05/2020 | James Thomas |
| Description | Optimisation of MBE graphene growth on exfoliated hexagonal boron nitride (hBN) has been developed by providing feedback on material growth. This has resulted in high quality and highly strained graphene, which is in some cases lattice matched to underlying hBN - a property that is unique to these samples. Using conductive atomic force microscopy (CAFM), and the moire pattern formed between graphene and hBN (as well as other techniques) the electronic properties and interaction between the tip and the graphene sample have been investigated in detail, where a substantial deformation of the sample surface has been observed. More recently graphene has successfully been epitaxially grown on epitaxially grown hBN in step flow growth forming lateral heterostructures and nanoribbons. This has also been achieved entirely within the same UHV system. |
| Exploitation Route | Graphene growth by MBE is continually progressing, new growth of graphene on MBE grown hBN may be used to grow tunelling devices entirely within the system in a potentially scaleable way, that may be used in the maufacture of novel electronics. This also applies to the graphene nanoribbon lateral heterostructures grown, which have a tunable width that could potentially introduce a bandgap to narrow nanowires. The modulation of the graphene surface observed may be used to explain some anomalies seen when scanning 2D materials, with an understanding potentially providing a route to improved imaging. In addition, these observations suggest that the graphene properties may be temporarily altered in a reproducible way by the introduction of a physical tip/applied pressure to the surface. |
| Sectors | Electronics,Other |
| Description | Various collaborative work with University of Nottingham Faculty of Engineering |
| Organisation | University of Nottingham |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Atomic force microscopy (AFM) and conductive AFM measurements carried out on multiple samples, including discussions and presentation of results as feedback. |
| Collaborator Contribution | The work carried out during these collaborations was primarily theirs, with no contribution towards our research. |
| Impact | AFM measurements as a result of this collaboration have been published in the following three papers (DOIs); 10.1016/j.corsci.2018.05.023, 10.1016/j.corsci.2019.108141, 10.1063/1.5089021. |
| Start Year | 2018 |