- Terahertz photonics
- Ultrafast spectroscopy
- Terahertz devices
- Semiconductor nanowires
- Physical vapour depositionEducation:
PhD in Physics, 2000, University of New South Wales
BSc (Hons) with University Medal, 1996, University of New South Wales
Michael Johnston is Professor of Physics at the University of Oxford and Honorary Professor at the Australian National University. He is a fellow of Corpus Christi College Oxford, and the Institute of Physics. Michael received his B.Sc.(Hons) from the University of New South Wales in 1996 and a PhD in Physics from the same institution in 2000. During his PhD he worked on quantum well infrared photodetectors (QWIPs) and how electrons behave in such quantum-confined systems. After postdoctoral work at the University of Cambridge’s Cavendish Laboratory, he joined the faculty at the Department of Physics, University of Oxford in 2002, where he established and currently leads a research group specialising on semiconductor physics, photovoltaics and terahertz photonics within the Clarendon Laboratory. His research achievements have been recognised by a series of awards including the Friedrich Wilhelm Bessel Research Award from the Alexander von Humboldt Foundation (2019), the Harrie Massey Medal and Prize from the Institute of Physics and Australian Institute of Physics (2018) and the IUMRS Somiya Award for International Collaboration Excellence in Materials Research (2017).
Professor Johnston’s research interests encompass the physics of charge dynamics in semiconductors and light-matter interactions. His research stretches from fundamental physics to real-world applications and encompasses the fields of terahertz (THz) science and technology, semiconductor nanostructures and photovoltaics. His main research focus areas at present are (i) studying fundamental charge-carrier dynamics in nanoscale and quantum-confined semiconductors by single-cycle terahertz probes, (ii) development of high frequency (THz) semiconductor devices and (iii) vapour deposition of metal halide perovskite semiconductors for solar cell applications.
In particular, he has studied charge-carrier dynamics in semiconductors nanowires by single-cycle terahertz probes, developing both instrumentation and new theories to uncover the underlying physics. Knowledge gained from these spectroscopic studies of fundamental charge dynamics in nanowires has led to the invention of novel ultra-high-speed photonic devices. Such devices include the first photoconductive THz detectors based on a single nanowire and an ultrafast terahertz modulator with picosecond switching times. He has also created a novel process for vapour deposition of metal halide perovskite semiconductors. This work was key to the creation of the first perovskite solar cell based on an efficient planar heterojunction architecture, now the gold standard in this area. The vapour deposition method has promise for the large-scale industrial production of cheap and high-efficiency solar cells for clean solar to electrical energy conversion.
Professor Johnston has written over 150 original research articles and was the instigator and editor of “The 2017 terahertz science and technology roadmap”. He is currently listed as a Web of Science Highly Cited Researcher.