Scheme: University Research Fellowship
Organisation: University of Oxford
Dates: Oct 2015-Sep 2018
Summary: Research in 2D materials has increased dramatically since the first isolation of graphene in 2004, with diverse interdisciplinary studies. In the last few years, 2D material research expanded beyond graphene by the development of other 2D materials, such as monolayered transition metal dichalcogenides, black phosphorous, and Boron Nitride. There are hundreds of possible 2D crystals that can be isolated, with properties ranging from metallic, semi-metallic, semiconducting to insulating, depending on the material composition. Semiconducting 2D materials have attracting interest in next-generation electronics/opto-electronics such as transistors, photo-gated transistors, photo-detectors, solar cells, and light emitting devices (LEDs), molecular sensors and optical imaging sensors. The unique structural form of 2D materials provides several benefits over other existing materials: ultrathin, flexible, highly transparent, large surface to volume ratio, and 2D quantum confinement. High transparency LEDs are required for applications in transparent displays on glass panels. Many 2D based opto-electronic devices have used mechanical exfoliation from bulk crystals, but this is limited to small areas. Recent work on chemical vapour deposition (CVD) to grow wafer-scale 2D materials has opened up exciting opportunities for commercial exploitation and has accelerated the intensity of research in this field towards real applications. The vision of this proposal is to realize a new class of ultra-thin, flexible, large-area, transparent, high-sensitivity opto-electronic device arrays based on all 2D materials, with a focus on imaging sensors and LEDs. This will involve wafer-scale CVD synthesis of 2D materials including novel blue and green 2D semiconductors, optical spectroscopy to probe the interlayer interactions, atomic level structure-property correlations using advanced electron microscopy, and the nanoscale fabrication and testing of high efficiency devices.
Dates: Oct 2010-Sep 2015
Summary: Electronics and computers are now integral to our everyday life, with mobile phones, ipods, memory sticks, cameras and laptops in routine use. Computing power that once occupied an entire floor of a building now fits into the palm of your hand. This was made possible by the miniaturization of electronic components. Building electronic components, such as transistors and interconnects, that are smaller and with new modes of operation is essential to the further advancement of technology. This proposal examines next-generation electronics that utilize carbon as the active electronic nanomaterial. Nanomaterial made from carbon, in particular graphene, are promising candidates to lead the next technological revolution in the electronics industry. Graphene is a 2D crystal one atom thick consisting of carbon atoms arranged in a hexagonal lattice with honeycomb pattern. Its large 2D sheet is ideal for cutting out sophisticated patterns of electrical circuits, including transistors in a top-down approach. I will develop the technology to grow large area graphene sheets using chemical vapour deposition and fabricate nanostructures with sub-10 nm features using a focussed electron beam. The electron beam will act as a knife and cut out tracks and patterns in the graphene sheet with atomic resolution. The graphene nanostructures will be made into electronic devices with improved performance. What makes this work extra-special is that I will use a state-of-the-art electron microscope which can magnify samples up to 2.6 million times and image the carbon atoms in graphene. By knowing how the atoms are arranged and I can understand how this affects the device performance and then fine tune the structure to improve the performance.