Chair
Dr Luca Sapienza, MInstP
University of Southampton
Luca’s research group, the Solid-State Quantum Optics Group, investigates light-matter interactions at the nanoscale with the aim of both unveiling fundamental quantum phenomena and fabricating novel devices with added quantum functionalities.
These research activities cover the electromagnetic simulation, fabrication and optical characterisation of quantum devices, via time-resolved photoluminescence spectroscopy down to cryogenic temperatures, for future computation and communication quantum technologies based on single photons on a chip.
The devices, made of GaAs and Si-based materials, consist of engineered, disordered and aperiodic photonic crystals, optical cavities and waveguides, embedding single epitaxial and droplet quantum dots as well as luminescent defect centres.
Secretary
Prof Matthew Halsall, FInstP
University of Manchester
Matthew’s research group studies the interaction of light with electronic devices and materials. The group’s research is very “applied” and most of the devices and materials it studies, such as light-emitting diodes and photovoltaic (solar PV) cells, are supplied by industry in the UK and overseas.
The group uses many physics-based techniques, such as low-temperature photoluminescence, Raman scattering and deep-level transient spectroscopy. It also collaborates with other groups nationally and internationally to access specialist techniques such as positron annihilation, secondary-ion mass spectrometry and electron microscopy.
The aim of all the techniques is to learn how defects in semiconductors affect device performance such as their energy efficiency and its stability. A recent result was the identification of a defect responsible for a loss of efficiency in commercial solar cells in the first few hours of their illumination by the sun.
This defect, with the rapid adoption of solar PV for electricity generation, now loses the planet the energy equivalent of >1Mt (metric ton) of carbon a year.
The materials studied by the group include silicon solar cells, and nitride-based LEDs and transistors. He also researches the integration of 2D materials into silicon for future device geometries.
Ordinary members
Dr Ian Sandall, MinstP
University of Liverpool
Ian is currently a lecturer in the Department of Electrical Engineering and Electronics at the University of Liverpool, prior to this he obtained his PhD in physics from Cardiff University (on the characterisation of quantum dot lasers) in 2007 and has worked for Philips Research in Eindhoven, and at the University of Sheffield (on mid-infrared photodetectors).
His research primarily concerns the development, characterisation and application of semiconductor-based electronic and photonic sensors. He has experience designing, fabricating and characterising a range of semiconductor-based devices (including transistors, laser diodes and avalanche photodiodes).
Recently this work has evolved into developing compact lab-on-a-chip-based biosensors utilising semiconductor electronic (and optoelectronic) devices as the active sensors.
Dr Juan Pereiro Viterbo, MinstP
Cardiff University
Juan’s research interests are very wide. Most of his research has orbited around thin-film growth and designing new experimental equipment to solve novel physical problems.
He has worked in III-N semiconductors, high-temperature superconductivity, new superconducting materials, interface superconductivity, magnetism, electron and atomic force microscopy, x-ray diffraction and nanostructure fabrication.
His current research focuses on the study of nucleation and relaxation phenomena in thin films and nanostructures of III-As semiconductors. Cardiff University’s LEEM laboratory hosts a unique Molecular Beam Epitaxy/Low Energy Electron Microscope system that allows real-time imaging of real and reciprocal space of the surface of the sample during growth with atomic resolution in z axis and 5-nanometre resolution in x-y directions. The low-energy electrons also allow strain and compositional contrast.
This is a very exciting system that the group will continue developing in order to enable the study of more complex systems. The goal is to understand the physics behind epitaxial growth and to provide complementary information to establish growth parameters to molecular-beam epitaxy (MBE) laboratories across UK.
Dr Adam Wright
University of Oxford
Adam is a postdoctoral researcher in the groups of Professor Laura Herz and Professor Michael Johnston at the University of Oxford, and a stipendiary lecturer in physics at Corpus Christi College, Oxford. His research is on metal halide perovskites, a class of materials which have recently achieved remarkable success in solar cells.
The rapid rate of improvement in the efficiencies of perovskite-based devices has however often outpaced understanding of the electronic processes occurring within these semiconductor materials. His work is concerned with providing insight into the factors influencing electron motion and recombination in a series of hybrid metal halide perovskites, principally using photoluminescence spectroscopy.
Such knowledge is essential for the development of higher-performance perovskite-based devices.
Former members
Dr Hareesh Chandrasekar
University of Bristol
His current research interests are in the device and reliability physics of wide-bandgap compound semiconductor devices for radio frequency (RF) and power-switching applications, mainly gallium nitride transistors.
A significant part of this involves developing novel electrical characterisation techniques along with device modelling to better understand the impact of material growth and processing on device performance. For his PhD, he worked on the MOCVD of GaN on Si substrates and developing bottom-up, low-defect density platforms for hetero-epitaxial GaN growth.
As part of continuous professional development Hareesh keeps up to date with the latest developments in a broad range of scientific subjects. Membership of the IET also helps to facilitate this activity, along with regular updates on the website content of leading companies and organisations.
Several areas of physics are key to the fabrication and processing of semiconductor materials such as optics, electronics and increasingly atomic physics as feature sizes continue to scale towards the atomic limit.
One example in optics is extreme ultraviolet lithography, which poses some of the most challenging questions in the transfer of physical principles into a high-volume manufacturing environment.
His motivations have always been to do interesting work which is commercially viable. His passion is to talk about the fundamental science and to engage the interest of others, whilst remembering that the underlying principles are based on our fundamental understanding of the physical world.
Mr Paul Harrison
EnSilica Limited
For over 30 years, Paul’s work has contributed to the fast-moving world of micro-electronics, which is now evolving into the nanotechnology realm. From being a design engineer in the early years of his career, with a background degree and PhD in physics, he has more recently been providing consultancy services to the semiconductor industry.
During these engagements, some with major blue-chip companies such as Ericsson and Philips Semiconductors (now NXP), Paul has made a policy of talking about science. So-called “Lunch and Learn” outreach talks cover topics from his own research as well as the latest innovations from within the integrated circuit (IC) design community.
In addition, he has also been invited to make branch-level presentations to the Institution of Engineering and Technology (IET), as well as the IOP. And, for a number of years, Paul has also given industry talks in several UK universities.
Dr Louise Hirst
University of Cambridge
Louise is a university lecturer jointly in the departments of Physics and Materials Science and Metallurgy at the University of Cambridge. Her research focuses on the development of advanced, high-efficiency III-V photovoltaics, with a particular interest in space power systems.
This includes the development and characterisation of novel III-V alloys and quantum-well systems, and the design and fabrication of alternative device geometries with integrated nanophotonic structures, as well as the development of hot-carrier solar cell concepts for high solar energy conversion efficiency in a relatively simple, thermodynamically elegant system.
She obtained her PhD from Imperial College London in 2012. She was then awarded a National Academy of Sciences Research Associateship held at the U.S. Naval Research Laboratory in Washington DC, where she became a federal government staff scientist and Karles Distinguished Scholar Fellow, before moving to Cambridge in 2018.
