The present electronic technology is approaching the limit to the smallest circuit element achievable, and the future electronic devices will depend critically on the development of novel approaches. Two dimensional materials seem to offer an exciting perspective, and the advent of graphene (a single layer of carbon atoms in a honeycomb structure) sparked a huge interest, but its application to electronics are limited by the absence of a band gap.
A new perspective has been open by other 2D materials which show a band gap. Combined with graphene in a stack (hetero-structure) they may open a new avenue, but a lot of work is required to refine the growth in order to obtain perfect structures without defects.
This project will explore the growth of these structures with advanced surface science techniques, for applications in nano electronics, sensing and energy storage.
Van der Waals epitaxy of transition metal dichalcogenides (TMDs) (namely MoS2 and WS2) will be investigated by using Scanning Tunneling Microscopy and Spectroscopy and other surface sensitive techniques.
Graphene is to be grown epitaxially on 4H- and 6H-SiC substrates by high temperature annealing in ultrahigh vacuum (UHV), and under an Ar atmosphere. This technique allows high quality epitaxial graphene/SiC samples to be grown with a controlled number of graphene layers.
Heterostructures of graphene and MoS2 will be synthesized by chemical conversion of Sulphur and MoO3 vapours in a horizontal tube furnace. The extent of the conversion reaction (from 2D Stranski Krastanov growth to 3D vertical platelets) can be controlled according to the reaction temperature and time.
Scanning probe lithography and helium ion microscopy (HIM) will be employed to investigate the growth and also to seed patterned domains of MoS2 through the controlled introduction of defects.
The student will have access to the multi-million dollar Central Analytical Research facility (CARF) in QUT, equipped with last generation SEM/TEM microscopes, FIB, Raman and with an Ultra High Vacuum Scanning Probe Microscope facility, which will be the core instrument for the project.
- Understand the kinetics and the thermodynamics of the growth processes.
- Obtain high-quality, large area heterostructures of graphene/SiC.
- Demonstrate the device capabilities of graphene heterostructures grown directly on SiC.
Skills and experience
The project is suitable for students with a strong background in physics, chemistry or materials science, or engineering.
This project is lab based and will require good laboratory skills and experience in physics and/or in chemistry.
Good software and programming skills are desirable.
You may be eligible to apply for a research scholarship.
Contact the supervisor for more information.