This project aims at advancing the field of Atomic Spin Gyroscopes (ASGs) towards the development of a commercial navigation grade device. ASGs exploit the Larmor precession of atomic spins in thermal vapours that contain a mixture of alkali-metal and noble gas atoms. Besides the potential for navigation grade performance, ASG benefit from a simple, robust hardware, which is ideal for miniaturisation. The activities within this project aim at developing and testing new techniques which will lead to performances comparable to or better than the best state-of-the-art laboratory-based systems, but with a simplified, less sophisticated architecture, more suitable for the out-of-the-lab application, and commercialization of ASG targeting inertial navigation. On one side this will fill the current gap in the performances between laboratory based ASGs and the first industrial prototypes, on the other side it will bring closer to commercialization a platform still full of unexplored (quantum) potential, which has the capability to surpass existent technology (such as optical and MEMs gyros) both in terms of performance over integration level and of absolute performance. The techniques we propose are based on the combined exploitation of stable spatial diffusion modes of the atomic gases, and methodologies developed, within our groups, for differential and self-adjusting operation. With a significant improvement of the short-term gyro sensitivity, long-term stability, and self-adjusting operation modes, we will specifically target the realization of robust gyros, compatible with apparatus miniaturization, and out-of-the-lab application in adverse environmental conditions. This technology development ideally complements several ongoing UK efforts for the development of the atomic spin system instrumentation, performed in collaboration with commercial partners. The results of the project will be also of interest for the wider academic and industrial community working in atomic magnetometry, and quantum science.

An efficient, practical and cost-effective means for directly converting heat into electricity is a very appealing concept. In principle, thermo-photovoltaic (TPV) cells could form the critical component of various systems for generating electricity from different types of heat sources including combustion processes, concentrated sunlight, waste process heat, and radio isotopes. This opens up a wide variety of possibilities for technology uptake and so TPV systems can be envisaged for use in applications ranging from small power supplies to replace batteries, to large scale co-generation of electricity. However, existing TPV cells are based on GaSb and are spectrally matched to heat sources at temperatures of ~1800 oC which limits their practical implementation and widespread uptake. GaInAsSb TPV cells with bandgap 0.53 eV have exhibited excellent performance with internal quantum efficiency near 95%. But, currently these are lattice-matched on GaSb substrates making them too expensive for practical implementation except in specialist high value or space applications. TPV development on larger format GaAs substrates will enable effective technology uptake through cheaper volume manufacturing of TPV cells. Consequently, there is a need to transfer the GaInAsSb cell architecture to GaAs. In this project we shall build on existing UK based world class III-V semiconductor materials expertise to fabricate novel low bandgap InGaAsSb TPV arrays on inexpensive GaAs substrates, capable of efficient electricity generation from thermal waste heat sources in the range 500-1500 oC commonly encountered in industrial processes. These monolithic arrays will be validated on-site together with our industry partners at Pilkington and MPIUK (Tata steel). The project will demonstrate the next step towards fabrication of large area TPV arrays essential for the commercial viability of TPV heat recovery, and will enable their widespread implementation in a wide range of high energy consumption industries such as glass, steel and cement manufacture, oil/gas and energy generation.

Compound Semiconductor (CS) materials are a Key Enabling Technology at the heart of modern society. They are central to the development of, for example, the 5G network, new energy efficient lighting, smart phones, satellite communications systems, power electronics for the next generation of electric vehicles and new imaging techniques. Simply put, these technologies support our connected world, our health, our security and the environment. The next generation of these technologies can only be achieved with a step change in CS manufacturing and we aim to the UK at the centre of this CS manufacturing research. This is not only important activity in its own right but will also support systems researchers in all of these important fields. The step change will be achieved by applying the manufacturing disciplines and approaches of Silicon to Compound Semiconductors and by combining CS with Silicon. This includes developing integrated epitaxial growth and processing with critical yield and reliability analysis; establishing new standards for CS device production, with a guaranteed number of wafer starts per week for key statistical based process control and development via IT infrastructure; solving the scientific and manufacturing challenges in wafer size scale-up combining large scale, 150-200mm diameter growth and fabrication for GaAs based and GaN based materials and apply this to existing and developed advanced processes; introducing a multi-project wafer culture (as is the norm in the silicon world) to share costs and encourage the widespread use of larger wafers by academics and SMEs. Critical to this approach is the characterisation equipment, which can be used in-line (during the manufacturing process) and over the larger (up to 200mm diameter) CS wafers we will utilise. This proposal is for this characterisation equipment to add to the large investment already made by Cardiff University and partners in epitaxial growth and fabrication infrastructure and equipment. We also ask for apparatus to allow high quality insulating layers to be deposited, which will enable the multi-project wafer approach to produce world leading performance, for access by our UK based circuit and system designers.

This proposal aims to bring to the UK an amazing microscope which will provide new and powerful capability in understanding the properties of light emitting materials and devices. These materials are key to many technologies, not only technologies that utilise the light emission from materials directly (such as energy efficient light bulbs based on light emitting diodes) but also a range of other devices which utilise the same family of materials such as solar cells and electronic devices for power conversion. Some of these technologies are in current use, but their efficiency and performance can be enhanced by achieving a better understanding of the relevant materials. Other target technologies are further from the market, but may represent the building blocks of our future security and prosperity. For example, the new microscope will provide information about light sources which emit one and only one fundamental particle of light (photon) on demand. Such "quantum light sources" are a potential building block for quantum computers and for quantum cryptography schemes which represent the ultimate in secure data transfer. How will the new microscope allow us to advance the development of all these technologies? It is based on a scanning electron microscope, which utilises an electron beam incident on a sample surface to achieve resolutions almost three orders of magnitude better than can be achieved using a standard light microscope. It thus accesses the nanometre scale, which is vital to addressing modern day electronic devices. Standard electron microscopy accesses the topography of a surface, but the incoming electron beam also excites some of the electrons within the material under examination into states with a higher energy. When these electrons relax back down to their usual low energy state, light may be given out, and the colour and intensity of that light is incredibly informative about the properties of the material under examination. This light emission can be mapped on a scale of ~10 nanometres so that nanoscale structures ranging from defects to deliberately engineered quantum objects can be addressed. This technique is known as cathodoluminescence, and has been in use for many years. The new capability of our proposed system is that it will map not only the colour and intensity of the light emission, but also allow us to measure the timescales on which an electron relaxes back down to its low energy state. We use the phrase "in the blink of an eye" to describe something that happens extraordinarily quickly. A real eye blink takes at least 100 milliseconds, whereas the relevant timescales for the electron to return to its low energy state could be almost 10 billion times quicker than this! The new microscope will be able to measure processes occurring on this time scale, by addressing how long after an electron pulse excites the material a photon is emitted. It will even be able to distinguish between photons with different wavelengths (or colours) being emitted on different time scales. Crucially, coupling this time-resolved capability with the ability to vary the temperature, we will be able to infer not only the time scales on which electrons relax to low energy sites emitting a photon, but also the time scales by which electrons reduce their energy by other, non-light-emitting routes. These non-light-emitting processes are what limit the efficiency of light emitting diodes, for example. Overall, across a broad range of materials, we will build up an understanding of how electrons interact with nanoscale structure to define a material's electrical and optical properties and hence what factors limit or improve the performance of devices. The proposed system will be the most advanced in the world, and will give UK researchers working on these hugely important photonic and electronic technologies a global advantage in developing new materials, devices and ultimately products.

The history of II-VI metal-organic chemical vapour deposition (MOCVD) goes back as far as IIII-V MOCVD but has not had the traction in applications for lasers, LEDs and high frequency devices that has been experienced by III-V semiconductors. A new generation of MOCVD equipment can more fully exploit the potential of II-VI semiconductors and explore new oxides and chalcogenides in the exiting areas of III-VIs such as Ga2O3 and 2-D semiconductors such as MoS2. There is now a compelling case for the UK to have state-of-the-art MOCVD equipment for compound semiconductors (CS) covering oxide and chalcogenide materials that are not covered by existing centres such as the National Epitaxy Facility at Sheffield, Cambridge and UCL, and Institute of CS at Cardiff. The UK has a golden opportunity to build on our strengths in CS research that will drive innovation across a range of new opto-electronic and power electronic devices. The need arises from a new generation of functional compound semiconductor materials to capture the unique properties of oxide and chalcogenide compound semiconductors (CSs), complementing III-V compounds and silicon, and opening new application areas in optoelectronics, energy and healthcare. It is proposed that we buy the Aixtron Close Couple Showerhead (CCS) reactor that has been proven to be the reactor design of choice for GaN deposition and will be the ideal equipment to deposit high quality oxide and chalcogenide compound semiconductor materials. "The UK needs this facility, which it does not have at present. Swansea is an excellent place for it." - Prof. Sir Colin Humphreys (Cambridge). "This proposed research facility will perfectly complement the installation of ~100 production MOCVD reactors leveraged by a £375M investment by IQE Plc over 2018-2022" - Dr Wyn Meredith (CSC, Cardiff). The CCS reactor will be installed in a new building for the Centre for Integrated Semiconductor Materials (CISM) (due for completion in Q1 2021) on the Swansea University Bay Campus. Over 140 m2 of specialist materials laboratory space will be allocated to the MOCVD reactor and complementary materials and characterisation equipment from Professor Irvine's laboratory. This new laboratory will be managed by Professor Irvine's team to provide high quality oxide and chalcogenide CSs to our research partners in Swansea University, other UK universities, industrial partners and to international collaborators. This will put the UK at the forefront of new science and technology using oxide and chalcogenide CSs for applications including high efficiency photovoltaic solar cells, Light harvesting quantum wire opto-electronic devices, piezoelectric energy harvesting, high breakdown voltage power electronic devices and light emitters. This new science and technology will benefit EPSRC priorities of "21st Century Products" and "Sustainable Industries" through enabling smart new products that could be rapidly prototyped through well proven manufacturing capability for MOCVD in the UK and enabling the application of more sustainable materials and reduced materials usage. This exciting opportunity is detailed in the case for support.