News

  • Acceleration of relativistic beams using laser-generated terahertz pulses

    A team of researchers including Dr Darren Graham, post-doctoral research associate Dr Morgan Hibberd, and PhD student Vasileios Georgiadis from the Photon Science Institute have successfully developed a pocket-sized particle accelerator capable of projecting ultra-short electron beams with laser light at more than 99.99% of the speed of light.

    To achieve this result, the researchers have had to slow down light to match the speed of the electrons using a specially designed metallic structure lined with quartz layers thinner than a human hair.

    In the new research published today in, Nature Photonics, the team of academics have successfully managed to use lasers to generate terahertz frequency pulses of light.

    For the full story, visit https://www.manchester.ac.uk/discover/news/scientists-create-compact-particle-accelerators-which-drive-1000-times-more-charge-to-near-the-speed-of-light/

  • Measurement and microscopic description of odd–even staggering of charge radii of exotic copper isotopes

    Researchers at Instituut voor Kern- en Stralingsfysica in Belgium and The University of Manchester, including PSI academic Kieran Flanagan, in collaboration with other institutes worldwide, have recently carried out a study aimed at measuring the size of the nucleus (i.e., nuclear charge radius) in neutron-rich copper isotopes. Their paper, published in Nature Physics, presents observations of a distinctive and interesting odd-even staggering pattern in the sizes of these isotopes' nuclei. To read the paper, visit https://www.nature.com/articles/s41567-020-0868-y

    Also, see a write up here https://phys.org/news/2020-05-radii-exotic-copper-isotopes.html  and some text from CERN https://ep-news.web.cern.ch/content/isolde-dives-deeper-mystery-odd-even-staggering-effect

  • Future Leader Fellowship Success

    The Photon Science Institute (PSI) is pleased to announce that 2 academics, Dr Patrick Parkinson (Department of Physics and Astronomy) and Dr Jessica Boland (Department of Electrical and Electronic Engineering), have both been appointed a Future Leader Fellowship (FLF) cohort. The FLF is a £900 million fund which is aimed at helping to establish world-leading researchers and innovators in both business and academia, is run by the UK Research and Innovation (UKRI).

     

    Dr Patrick Parkinson

    Big-data for nano-electronics

    The modern world runs on nanotechnology; we are connected by a fibre-network using nanostructured lasers, and use computers and phones made of nanometre scale transistors. The next generation of nanotechnology promises to incorporate multiple functionalities into single nanomaterial elements; this is “functional nanotechnology”. Here, the size of the material itself provides functionality – for instance for sensing, computing, or interacting with light.  The most powerful and scalable approaches to making these structures use bottom-up or “self-assembled” methods; however, as this production technique emerges from the laboratory and into industry, issues such as yield, heterogeneity, and functional parameter spread have arisen.

    Functional performance in these nanomaterials is determined by geometry. As such, variations in size or composition affect performance in complex ways. In this project, I will combine high-speed and high-throughput techniques to measure the shape, composition and performance of hundreds of thousands of functional nanoparticles from each production run. By combining this big data with statistical analytics, I will create a new methodology to understand and then optimize cutting-edge functional nanomaterials, working with academic partners in Cambridge, University College London, Strathclyde, Lund (Sweden) and the Australian National University, and industrial partners including AIXTRON and Nanoco.

    The ultimate goal of this project is to enable demonstration and scale-up of transformative devices based on novel nanotechnology, for sensing, computing, telecommunication and quantum technology.


    Dr Jessica Boland

    Terahertz, Topology, Technology: Realising the potential of nanoscale Dirac materials using near-field terahertz spectroscopy

    Technology is constantly evolving. Even within our lifetime, devices have become noticeably faster and smaller with increased functionality; yet these 'smart' devices still suffer from high power consumption and poor energy storage. Integrative photonic, electronic and quantum technologies are key to creating the next-generation of devices that are more energy-efficient with unprecedented performance. Advanced functional materials will  form the basis of these new technologies. Dirac materials, in particular, have attracted significant attention as candidates for novel devices, owing to their extraordinary optoelectronic properties. For these materials, the surface hosts Dirac electrons that are immune to backscattering from non-magnetic impurities and defects. Their direction of travel is fixed by their inherent angular momentum or 'spin', so they behave as if on a railway line - travelling with less resistance and heat production. In particular, these materials have emerged as promising candidates for novel terahertz (THz) device, which are poised to impact several sectors, including security, food processing, healthcare and wireless communication. However, to realise their full potential, an in-depth understanding of key device parameters (e.g. conductivity) in these materials is vital.

    This research project aims to provide non-destructive material characterisation at 3 extremes: nanometre (<30nm) length scales, ultrafast (<1ps) timescales and low temperatures ( <10K).  By employing scattering-type near-field optical microscopy (SNOM) with ultrafast optical-pump terahertz-probe (OPTP) spectroscopy (OPTP-SNOM), their surface photoconductivity response will be mapped for the first time with <30nm spatial and <1ps temporal resolution. Working with University of Leeds, Oxford and NPL, nano-tomography will be performed to form a 3D map of local carrier concentration, carrier lifetime and electron mobility, providing deeper insight into their optoelectronic properties.  Utilising this newfound knowledge, the exclusive P-NAME facility at Manchester will be used to spatially dope optimised materials with <40nm spatial accuracy to control electronic properties on nanometre length scales. This will allow design of bespoke nanosystems for device applications, such as THz emitters and detectors. In collaboration with Teraview, these systems will allow development of prototype THz devices  for healthcare imaging systems and ultrafast wireless communication.

     

  • PSI Academic wins Philip Leverhulme Prize 2019

    Congratulations to Dr Jessica Boland, PSI academic and Lecturer in Functional Materials and Devices in the Department of EEE, who has received the Philip Leverhulme Prize for engineering. Dr Boland, also of the Photon Science Institute, was recognised both for her achievements so far and her exceptional promise in this field. She is one of 30 prize winners, each receiving £100,000 to be used over two or three years to advance their research.

    Find out more about the Philip Leverhulme Prizes.

    Jess Boland

  • PSI Student Success

    2 PSI PhD students have recently won awards.

    Pip Clark has been awarded the 2018 Franks Thesis Prize of the IoP's Nanoscale Physics and Technology Group. This was awarded in recognition of Pip's outstanding contributions to the nanoscale physics of colloidal quantum dots (CQDs) for application in solar nanocells, completed in 2018 under the supervision of Prof. Wendy Flavell.

    Jack Cun-Ren Ke obtained a highly competitive Graduate Student Award in EMRS 2019 Spring Conference.

    Congratulations to both!

  • Professor Lin Li wins Arthur L. Schawlow Award

    At the Laser Institute of America (LIA) annual meeting held at the 38th International Congress on Applications of Lasers & Electro-Optics, in Orlando, USA, 9th October 2019, PSI academic, Professor Lin Li, received the prestigious Arthur L. Schawlow award from the LIA, In recognition of his pioneering research and development of laser based manufacturing processes and his entrepreneurial drive and vision to commercialize technologies.

    Arthur Schawlow received a Nobel Prize for Physics in 1981 for his contribution to the development of laser spectroscopy. LIA established the Arthur L. Schawlow Award, since 1982, to recognize individuals who have made outstanding, career-long contributions to basic and applied research in laser science and engineering leading to fundamental understanding of laser materials interaction and/or transfer of laser technology for increased application in industry, medicine and daily life.

    Lin Li Award

  • Bruker Prize Winner 2020

    Congratulations to PSI academic, Prof. David Collison who was recently announced as the winner of the 2020 Bruker Prize for EPR Spec-troscopy. This is one of the highest awards in EPR world-wide, and David will be the 35th recipient since the inaugural award in 1986, and only the 4th to hail from the UK.

    The award is given to a scientist who has made a major contribution to the application of EPR/ESR spectroscopy in chemical or biological systems. The nominations emphasised David’s seminal contributions to experimental and theoretical fundamentals of transition metal EPR, from bioinorganic chemistry to molecular materials, including his authoritative textbook. Crucially, they also stressed his important and selfless work in developing, supporting and nurturing the EPR community throughout his career. As co-founder and director of the successful EPSRC UK National EPR Facility, he has fostered collaboration not only between EPRists, but also between the EPR and wider science communities. This has had significant impact in widening the application base and popularising applications of EPR across the scientific spectrum.

    David Collison Picture

  • Dr Jessica Boland wins award

    The British Science Association have just announced the winners of their prestigious Award Lectures for 2019. Dr Jessica Boland (PSI and EEE) is the Isambard Kingdom Brunel Award Lecture winner for Engineering, Technology and Industry for her lecture entitled: 'Smaller, better, faster: 21st century nanomaterials.' In thsi talk, Jessica asks, How do you study the incredibly small? Nanomaterials are crucial for ‘nanodevices’, which have impacts in food production, medicine and controlling pollution. But working on such small materials (one billionth of a metre) in size isn’t easy. Despite this, Jessica Boland is managing to examine new, cutting-edge nanomaterials that are 100 times faster than silicon by using a special visualisation technique,. Join the Institute of Physics Jocelyn Bell Burnell Medal and Prize winner in this talk, exploring how her research at the University of Manchester has the potential to drastically change society, contributing to the creation of a new generation of nanodevices that are smaller, better and faster.   



  • Prof Richard Curry and Dr Iain Crowe visit Nepal

    In 2018 PSI researchers, Dr. Iain Crowe and Prof. Richard Curry were awarded a significant (£1.3M) EPSRC-Global Challenges Research Fund (GCRF) grant (EP/R014418/1) to develop miniature ‘on-chip’ optical coherence tomography (OCT) imaging techniques with focus on in-vivo healthcare applications.

    Collaborating with researchers at the University of Glasgow, Harvard Medical School in the US, Ghent University in Belgium and the Nepalese based team at the Phutung Research Institute, they hope to demonstrate how the technique of OCT – the optical equivalent to ultrasound (but with significantly higher resolution) - can be applied to diagnosis and progress monitoring of acute lung disorders, which are especially prevalent in Nepal. The ability to translate the technique, currently based on bulky optical components - lasers, interferometers, spectrometers and detectors, all linked by single mode optical fibres - onto a silicon chip, has the potential to revolutionise biomedical imaging, providing performance on a par with MRI or CT scanning methods, but at a fraction of the cost, especially important where healthcare access is severely limited. Since the award of the grant, the researchers have been working on their first, sub-m waveguide based interferometer designs, based on the silicon photonics architecture, which occupy a footprint of just 1mm2 on a chip, similar to that shown in the image above. Fabrication of these first devices was completed at the beginning of 2019 and ‘off-chip’ optical characterisation is currently underway.

    Picture from Nepal  Picture from Nepal

    In March/April this year, Iain and Richard were invited to attend a seminar, along with healthcare officials, clinicians, engineers, Nepalese stakeholders and government ministers, in Kathmandu, where this first prototype device was unveiled and demonstrated (the first nano-photonic device of its kind developed in conjunction with a Nepalese based research team!). Iain and Richard gave invited talks and led discussions on the project, as well as on more general research activity in photonics at Manchester and the importance of the role this kind of research can play in the context of GCRF projects.

    The trip included visits to pulmonology units at the major medical centres in Kathmandu, meeting with lead clinicians on the ground, to gain a better understanding of the challenges they face in delivering healthcare in this area, with very limited resources. They also toured some of the more remote, high altitude health centres, in the Khumbu region; including Namche Bazar (at 3400m), Kunde hospital (at 3840m, founded by Sir Edmund Hillary in 1966), Machhermo (at 4470m) and Gokyo (at 4790m where the technology developed as part of this project could eventually be implemented as part of a conventional bronchoscopy facility, providing access to sophisticated biomedical imaging, not currently available to the local population. The return leg of their journey took them over Renjo-la pass at an altitude of 5345m (17,536ft), where they were treated to wonderful views of several of the world’s highest mountains, including Mt. Everest.

    Picture from Nepal  Curry and Crowe at Everest

    The next phase of the project considers how the delivery/collection of light will be achieved between the device and organic test samples, as well as integration of miniature broadband light sources (based on III-V semiconductor laser diode technology, being developed in Glasgow) with the silicon photonics interferometer. The project ties in nicely with the recently funded (and now installed in the PSI) Royce facility, which provides commercial (Thorlabs) fibre based spectral domain OCT at both 900nm and 1300nm.

  • EEE/PSI student wins PGR student of the year award

    EEE/PSI student Michelle Vaqueiro-Contreras has won this year’s FSE award for postgraduate student of the year by solving a 40 year long mystery of why silicon photovoltaic (PV) cells lose some of their efficiency within the first hours of operation. Working under the supervision of Professor Matthew Halsall, Michelle identified the defect responsible as a complex of Boron with two oxygen atoms that initially lies ‘dormant’ in the bulk of the silicon but is transformed into a powerful recombination centre when the cell is exposed to sunlight. This causes electrons in the silicon to lose energy through a process known as “Trap Assisted Auger” which converts it to heat, rather than the electricity desired. The identification was an amazing piece of detective work involving EEE/PSI researchers, Dr. Vladimir Markevich, Dr Iain Crowe and Emeritus Professor Tony Peaker, along with Collaborators in Portugal and Belarus.

    Despite the success of silicon PV in recent years, the best commercially available solar panels are still only around 20% efficient, i.e. for every 5W of equivalent sunlight, about 1W of electrical power can be generated. It’s perhaps even less widely known that, during the first hours of operation, after installation, this efficiency drops to about 18%, as a result of what is known as Light Induced Degradation (LID). An absolute drop of 2% in efficiency may not seem like a big deal, but when you consider that these solar panels are now responsible for delivering a large (and rapidly growing) fraction of the world’s total installed electrical generating capacity, it represents a significant loss of power. For context, the size of the loss, globally (~50GW) is equivalent to the generating capacity of approximately 42 modern nuclear reactors, similar to the Sizewell B power plant in the UK. Worst of all, this shortfall has to be met by other, less sustainable energy sources, i.e. by burning fossil fuels, which contributes to an increase in the level of CO2 generated!

    Precisely because of the impact (financially, as well as environmentally) of this reduced renewable energy generating capacity, solar panel ‘efficiency degradation’ - specifically LID - has been the topic of much scientific and engineering interest in the last 4 decades. However, despite some of the best minds in the business working on it, the problem has steadfastly resisted resolution. It was this problem that the EEE/PSI group determined Michelle should revisit for her PhD. Amazingly Michelle discovered an electrical signal from the defect that had previously been missed, likely because of the unusual experimental conditions needed to observe it. Along with important contributions from colleagues at the University of Aveiro in Portugal and the National Academy of Sciences in Belarus, the findings have now been published in the Journal of Applied Physics (https://aip.scitation.org/doi/10.1063/1.5091759), where it has been selected as a feature article.

    The article describes the multi-disciplinary experimental and theoretical approach employed by the researchers to identify the mechanism responsible for LID. Combining a specialised electrical ‘junction’ technique, known as ‘deep-level transient spectroscopy’ (DLTS), developed and perfected by the team at the University of Manchester over many years, with world class optical spectroscopy facilities, in the Photon Science Institute (https://www.psi.manchester.ac.uk/), they have shown how, under the action of light, or electrically injected charge carriers, an energetically ‘deep’ boron-di-oxygen-related ‘donor’ state is converted into an energetically ‘shallow acceptor’ state, which is strongly correlated with the change in minority carrier lifetime, in the silicon material. Theoretical work, based on ab initio modelling, carried out by collaborators at the University of Aveiro in Portugal, reveals precise details of the BsO2 defect structures that match these experimental observations.

    The researchers are keen to point out that, although several ‘engineering solutions’ to the LID problem were previously proposed, with the potential to limit its effects, without a proper understanding of the fundamental mechanism responsible, it has been difficult to predict whether these would guarantee production performance for the 25 year lifetime of the solar panels. This latest finding represents a major breakthrough because it provides a much better understanding of the problem, meaning that we can at last look at ways to eliminate it completely! This is great news for the planet in a month which has seen atmospheric CO2 levels surpass the highest in human history (https://eu.usatoday.com/story/news/world/2019/05/13/climate-change-co-2-levels-hit-415-parts-per-million-human-first/1186417001/)!

    The work was funded by EPSRC as part of their Supergen solar challenge, grant title: SuperSilicon PV: extending the limits of material performance (EP/M024911/1).

     

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