This proposal addresses the two major roadblocks in the development of graphene for high-performance nano-optoelectronics, namely how to efficiently and reliably integrate them in pristine conditions in electronic devices, and how harness the exceptional properties of graphene. Specifically, proof of principle of ultra-thin body tunnel field effect transistors (UB-TFET) are proposed consisting of two-dimensional (2D) all epitaxial graphene/boron nitride heterostructures with a viable large scale integration scheme. Tunnel transistors are an efficient alternative to standard field effect transistors designs that are inefficient for graphene because of the lack of a bandgap. Importantly UB-TFET should overcome the thermal limitation of thermioic sub-threshold swing in common transistors. The TFET will be based on epitaxial graphene on SiC (epigraphene, or EG)/BN structures; the most advanced implementation will utilize the recently discovered exceptional conductance properties of epigraphene nano-ribbons that are quantized single channel ballistic conductors at room temperature. But having excellent graphene is far from having a device and the active component has to be integrated. This project is based on the fundamental realization that only (hetero)-epitaxial growth can provide the required atomic control for reliable devices. Epitaxial growth insures clean interfaces and precise orientation of the stacked layers, avoiding trapped molecules and the randomness inherent to layer transfer. However, despite this absolute requirement, very little progress has been made up to now to grow large 2D dielectric on graphene; most dielectric deposition needs chemical modification of the graphene surface for adhesion, which invariably compromises the graphene electronic performance. Hexagonal boron nitride (h-BN) layers is considered the best substrate for graphene, but only micron size BN flakes are available, making the integration tedious, unreliable and impossible at large scale. In this proposal we will grow h-BN epitaxialy on epigraphene by metalorganic vapor phase epitaxy (MOVPE). As demonstrated in preliminary work by this three-team partnership, this technique provides exceptional unmatched graphene/h-BN epitaxial interfaces as required for high performance electronics, and immediate upscaling capabilities. The SiC/EG/h-BN heterostructure will give access to graphene properties in an exceptionally reproducible and clean environment, not otherwise available. Growth conditions will be investigated to produce ultra thin h-BN on epigraphene, which have not been achieved yet. This proposal will then follow two tracks to build UB-TFETs, demonstrating proof of principle of vertical and lateral BN/EG-based FETs. Our ultimate goal is to combine ballistic epigraphene nanoribbons in tunneling devices to enable a new generation of electronic devices. This is an extremely promising alternative to the standard FET paradigm that can enable ultra-high frequency operation as well as low power operation. This project is a tight well-focused partnership between three teams with a history of highly successful collaboration and perfect complementarity: CNRS-Institut Néel (Grenoble), CNRS/ONERA-Laboratoire d’Etude des Matériaux (Châtillon), and CNRS/Georgia Institute of Technology -UMI 2958 (Metz, in collaboration with GT Atlanta). We will build up on the important milestone of epitaxial h-BN growth on EG, towards critical development including ultra-thin BN and fabrication of tunnel transistors devices. IN will be in charge of providing epigraphene, will design and realized transistor devices and perform transport measurements; the UMI team will produce the BN epitaxial film and provide basic structural study for rapid optimization of the growth process; LEM will perform advanced structural and optical studies, in particular HR-TEM studies, critical to the layer characterization of ultra thin 2D films.

Reducing carbon emissions and securing energy supplies are crucial international goals to which energy demand reduction must make a major contribution. On a national level, demand reduction, deployment of new and renewable energy technologies, and decarbonisation of the energy supply are essential if the UK is to meet its legally binding carbon reduction targets. As a result, this area is an important theme within the EPSRC's strategic plan, but one that suffers from historical underinvestment and a serious shortage of appropriately skilled researchers. Major energy demand reductions are required within the working lifetime of Doctoral Training Centre (DTC) graduates, i.e. by 2050. Students will thus have to be capable of identifying and undertaking research that will have an impact within their 35 year post-doctoral career. The challenges will be exacerbated as our population ages, as climate change advances and as fuel prices rise: successful demand reduction requires both detailed technical knowledge and multi-disciplinary skills. The DTC will therefore span the interfaces between traditional disciplines to develop a training programme that teaches the context and process-bound problems of technology deployment, along with the communication and leadership skills needed to initiate real change within the tight time scale required. It will be jointly operated by University College London (UCL) and Loughborough University (LU); two world-class centres of energy research. Through the cross-faculty Energy Institute at UCL and Sustainability Research School at LU, over 80 academics have been identified who are able and willing to supervise DTC students. These experts span the full range of necessary disciplines from science and engineering to ergonomics and design, psychology and sociology through to economics and politics. The reputation of the universities will enable them to attract the very best students to this research area.The DTC will begin with a 1 year joint MRes programme followed by a 3 year PhD programme including a placement abroad and the opportunity for each DTC student to employ an undergraduate intern to assist them. Students will be trained in communication methods and alternative forms of public engagement. They will thus understand the energy challenges faced by the UK, appreciate the international energy landscape, develop people-management and communication skills, and so acquire the competence to make a tangible impact. An annual colloquium will be the focal point of the DTC year acting as a show-case and major mechanism for connection to the wider stakeholder community.The DTC will be led by internationally eminent academics (Prof Robert Lowe, Director, and Prof Kevin J Lomas, Deputy Director), together they have over 50 years of experience in this sector. They will be supported by a management structure headed by an Advisory Board chaired by Pascal Terrien, Director of the European Centre and Laboratories for Energy Efficiency Research and responsible for the Demand Reduction programme of the UK Energy Technology Institute. This will help secure the international, industrial and UK research linkages of the DTC.Students will receive a stipend that is competitive with other DTCs in the energy arena and, for work in certain areas, further enhancement from industrial sponsors. They will have a personal annual research allowance, an excellent research environment and access to resources. Both Universities are committed to energy research at the highest level, and each has invested over 3.2M in academic appointments, infrastructure development and other support, specifically to the energy demand reduction area. Each university will match the EPSRC funded studentships one-for-one, with funding from other sources. This DTC will therefore train at least 100 students over its 8 year life.

We will train a cohort of 65 PhD students to tackle the challenge of Data Creativity for the 21st century digital economy. In partnership with over 40 industry and academic partners, our students will establish the technologies and methods to enable producers and consumers to co-create smarter products in smarter ways and so establish trust in the use of personal data. Data is widely recognised by industry as being the 'fuel' that powers the economy. However, the highly personal nature of much data has raised concerns about privacy and ownership that threaten to undermine consumers' trust. Unlocking the economic potential of personal data while tackling societal concerns demands a new approach that balances the ability to innovate new products with building trust and ensuring compliance with a complex regulatory framework. This requires PhD students with a deep appreciation of the capabilities of emerging technology, the ability to innovate new products, but also an understanding of how this can be done in a responsible way. Our approach to this challenge is one of Data Creativity - enabling people to take control of their data and exercise greater agency by becoming creative consumers who actively co-create more trusted products. Driven by the needs of industry, public sector and third sector partners who have so far committed £1.6M of direct and £2.8M of in kind funding, we will explore multiple sectors including Fast Moving Consumer Goods and Food; Creative Industries; Health and Wellbeing; Personal Finance; and Smart Mobility and how it can unlock synergies between these. Our partners also represent interests in enabling technologies and the cross cutting concerns of privacy and security. Each student will work with industry, public, third sector or international partners to ensure that their research is grounded in real user needs, maximising its impact while also enhancing their future employability. External partners will be involved in PhD co-design, supervision, training, providing resources, hosting placements, setting industry-led challenge projects and steering. Addressing the challenges of Data Creativity demands a multi-disciplinary approach that combines expertise in technology development and human-centred methods with domain expertise across key sectors of the economy. Our students will be situated within Horizon, a leading centre for Digital Economy research and a vibrant environment that draws together a national research Hub, CDT and a network of over 100 industry, academic and international partners. We currently provide access to a network of >80 potential supervisors, ranging from leading Professors to talented early career researchers. This extends to academic partners at other Universities who will be involved in co-hosting and supervising our students, including the Centre for Computing and Social Responsibility at De Montfort University. We run an integrated four-year training programme that features: a bespoke core covering key topics in Future Products, Enabling Technologies, Innovation and Responsibility; optional advanced specialist modules; internship and international exchanges; industry-led challenge projects; training in research methods and professional skills; modules dedicated to the PhD proposal, planning and write up; and many opportunities for cross-cohort collaboration including our annual industry conference, retreat and summer schools. Our Impact Fund supports students in deepening the impact of their research. Horizon has EDI considerations embedded throughout, from consideration of equal opportunities in recruitment to ensuring that we deliver an inclusive environment which supports diversity of needs and backgrounds in the student experience.

While silicon-based solar cell technologies dominate the photovoltaic (PV) market today, their performance is limited. Indeed, the world record efficiency for Si-based PVs has been static at 25% for several years now. III-V multijunction PVs, on the other hand, have recently attained efficiencies > 40% and new record performances emerge regularly. Although tandem PV geometries have been developed combining crystalline and amorphous silicon, it has not been possible so far to form devices with efficiencies to rival III-V multijunctions. NOVAGAINS aims to benefit from combining the maturity of the Si technology with the potential efficiency gains associated with IIIV PV through the development of a novel tandem PV involving the integration of an InGaN based junction on a monocrystalline Si junction by means of a compliant ZnO interfacial template layer which doubles as a tunnel junction. Although the (In)GaN alloy has been used extensively in LEDs, its’ use in solar cell technology has drawn relatively little attention. Nevertheless, the InGaN materials system offers a huge potential to develop superior efficiency PV devices. The primary advantage of InGaN is the direct-band gap, which can be tuned to cover a range from 0.7 eV to 3.4 eV. As such, this is the only system which encompasses as much of the solar spectrum. Indeed, the fact that InGaN can provide such tunability of the bandgap means that PV conversion efficiencies greater than 50% can be anticipated. Unfortunately, it is very difficult to grow GaN based films of high materials quality directly on Si because they do not have a good crystallographic match. ZnO can be grown more readily on such substrates, however, because of its’ more compliant nature. Indeed, well-crystallized and highly-oriented ZnO can even be grown directly on the native amorphous SiO2 layer. Since ZnO shares the same wurtzite structure as GaN and there is less than 2% lattice mismatch it has been demonstrated that it is then possible to grow InGaN/GaN epitaxially on ZnO/Si using the specialized know-how offered by the consortium. Modeling indicates that when optimized, stacked InGaN and Si cells coupled by tunneling through a ZnO interlayer offer the perspective of tandem cells with overall solar conversion efficiencies in excess of 30%.

This project will extend and enhance the Firedrake automated finite element simulation system to allow researchers across the field of continuum mechanics to simulate a wider range of physical phenomena using more sophisticated techniques than they would be able to code themselves, and to do so by specifying the simulation from highly productive mathematical interface embedded in Python. The simulation of continuous physical systems described by partial differential equations (PDEs) is a mainstay activity of computational science. This spans the integrity of structures, the efficiency of industrial processes built on fluid flow, and the propagation of electromagnetic waves from an antenna to name but a few. Each simulation demands the choice of an appropriate PDE, an accurate and stable discretisation, the efficient parallel assembly of the resulting matrices and vectors, and the fast, scalable solution of the resulting numerical system. Every simulation is the composition of a chain of processes, each of which is a research domain in its own right. Most computational continuum mechanics research happens in small teams. These groups constantly tackle new problems, needing changes at every level of the simulation chain. The challenge is to allow individual researchers and small teams to put together their own simulations, without requiring the impossible by every researcher becoming an expert on the implementation of every stage of the process. Firedrake employs a mathematical language embedded in Python that enables researchers to write the simulation they wish to execute in a highly productive and concise way. The high performance parallel implementation of the simulation is then automatically generated by specialised compilers at runtime. The result is a system in which scientists and engineers write maths and get simulation. This frees researchers to focus on the continuum mechanics question at hand rather than the mechanics of creating the simulation. Firedrake is a widely employed community code with hundreds of published applications across continuum mechanics. For many researchers, Firedrake clearly already meets at least some of their needs. However, the sophistication of continuum mechanics research is boundless: there are always users and potential users whose problems cannot fully be expressed in Firedrake's high level mathematical language. This project will address several such limitations, chosen in response to formal Firedrake user engagement over the last two years. First, we will extend Firedrake's capabilities in solving coupled multi-domain systems. This will enable Firedrake users to more effectively tackle simulation challenges such as the impact of sea waves on wind turbine columns. Second, we will extend Firedrake's automated inverse capabilities to include complex-valued problems. This will significantly benefit users wishing to simulate optimal design problems involving electromagnetic waves. Third, we will extend the range of meshes that Firedrake can employ to include unstructured hexahedral meshes, and hierarchically refined meshes. This will improve Firedrake's support for efficient high order discontinuous Galerkin discretisations and for multiscale problems such as folding of materials. In addition to extending Firedrake's technical capabilities, this project will grow and support the community of continuum mechanics researchers using Firedrake. We will reduce the technical knowledge needed to install Firedrake by providing packages for the main desktop operating systems. We will run tutorials, workshops, and provide online support to new and existing Firedrake users. An "open door" programme of user visits to the Firedrake core developers will provide personal one on one assistance with their simulation needs. We will invest significant time in the extension and maintenance of Firedrake's high quality documentation.