Electronics and photonics has transformed everyday life over the last twenty years: the silicon microprocessor provides vast processing power in a device that can fit inside a pocket, the liquid crystal display allows us to see information on a high resolution display that can sit on the palm of our hand, and the optic fibre allows us to transmit data at high speeds over long distances. The result is that we are all essentially continuously connected to the internet, and this allows us to communicate with each other and access information instantly. The result has been a profound change in almost every aspect of life including working practices, shopping, healthcare, banking, transport and even relationships. However, whilst we are 'connected', the world of objects that are so much part of our everyday lives are not, and the next big transformation will be to connect these too. This is the vision of the 'Internet of Things'. In the words of Prime Minister David Cameron, 'I see the Internet of Things as a huge transformative development, a way of boosting productivity, of keeping us healthier, making transport more efficient, reducing energy needs, tackling climate change. We are on the brink of a new industrial revolution.' Advances in technology are the driver for such industrial revolutions, and the Internet of Things needs sensors, rfID, power supplies, logic, displays, lighting and communications to be integrated together onto the everyday objects around us with a form factor that does not adversely affect the prime function of the object, whether that object is our car, our refridgerator, our clothes, our purse or our toothbrush. This will require a new generation of electronics which can be produced transparently over large areas on almost any substrate, and which is flexible and robust. Such 'large-area electronics' on glass substrates based on amorphous silicon (a technology born in Dundee University in the 1970s) has already been critical for the development of flat panel displays. However, amorphous silicon is not optically transparent and has rather poor electronic properties (most nobably a low electron mobility). Amorphous ionic oxides have emeged as a replacement for amorphous silicon for display applications in recent years as it has superior electronic properties. In particular, amorphous indium gallium zinc oxide (a-IGZO) has been developed to such a point that it will shortly start to be used in commercial products. However, this complex material can only be made as a n-type and not a p-type semiconductor, and so complemetary logic cannot be realised with the result that power consumption is high. Also, it suffers from instabilities which limits its lifetime. As a result, this material is less well suited to the Internet of Things. This project aims to develop a more simple n-type amorphous ionic oxide semiconductor with an improved stability over a-IGZO, and a complementary p-type amorphous ionic oxiide semiconductor. This will require detailed understanding of the physics of these materials, and in particular the electronic role of impurities. We will subject both the individual materials and devices made from these materials to a wide range of physical tests, including infrared spectroscopy, allowing us to study the device in its applied environment. This is critical as the performance of a thin film device is often dominated by its surfaces. This will enable us to develop both new materials and models for devices which are critical for the design and simulation of circuits and systems. This is critical if the technology is to be applied. We will demonstrate the validity of our materials, processes, models and their application by designing, simulating, fabircating and testing a four-bit rfID tag on a plastic substrate. The cost of producing these devices should end dup being similar to printing, allowing in-line manufacture with the rest of the object they are enabling in the UK.
The Fellow and his team are seeking to develop a ground-breaking electronic device named the multimodal transistor. Arising from more than a decade of experience in unconventional device design, it allows for entirely new applications such as hardware learning, analog computation and control, while being energy efficient and easy to fabricate. News headlines in electronic devices usually hail developments in nanoscale billion-transistor chips, yet there are major opportunities for innovation in display screen technologies, in which the requirement of fabricating circuits at low cost over large areas, and not ultimate miniaturization, is prevalent. Existing fabrication facilities are now partly being repurposed for emerging large area electronic (LAE) applications: microfluidics, lab-on-a chip, ubiquitous sensors or wearable electronics. LAE usually contain large arrays of relatively simple circuits with few transistors, as areal performance variations impede the fabrication of complex circuits. Incremental progress in LAE is constantly achieved through processes and equipment improvements, and by using new materials with superior properties, both with large capital investment. The Fellow proposes a major step in LAE development, a radical new device design: the multimodal transistor (MMT). The MMT enables new ways of designing electronic circuits for efficient analog operations (amplification, data conversion, analog computation), control and feedback, and ultimately, LAE circuits capable of learning (hardware AI), so far impractical with conventional devices and techniques. Functionality is achieved using energy-efficient circuits of minimal complexity, allowing environmentally friendly fabrication at low cost. By greatly expanding the design possibilities, while being entirely compatible with conventional LAE fabrication, MMT circuits extend the usable lifetime of current manufacturing technologies, maximising the return on investment, and can accelerate the uptake of emerging processes such as 2D semiconductors and spatial atomic layer deposition. The Fellow's team will leverage our long experience in device design and the complementary capabilities of our international partners to design, fabricate and test devices and circuits using vacuum processing and additive manufacturing in conventional and emergent semiconductor systems, supported by state-of-the-art numerical simulation. The team will use their extensive collaborator networks to seed the development of a new electronic design paradigm. As this is an enabling technology, its applications span fields from disposable medical diagnostics and crop monitoring to autonomous vehicle control, new forms user interfaces and immersive entertainment environments, with substantial long term economical and public benefits for the UK and the world. The implications of the novel functionality, such as hardware AI and autonomy, will be a constantly considered. Stakeholders will be involved in shaping the research through cross-disciplinary workshops, online engagement and science festival participation. The focus on people will further include: continuing a decade-long tradition of training, mentoring and involving school students in the Fellow's research; supporting a strong start to the careers of young researchers involved through mentoring, independence and due to the ground-breaking nature of the work; and incorporating the findings into Surrey's teaching curriculum to increase our graduates' employability. The Fellowship will accelerate the Fellow's growth as an international technical and thought leader, while retaining valuable skills, intellectual property and know-how in the UK at a time of global uncertainty. A Fellowship is the optimal funding route, allowing full commitment to advancing this trailblazing design paradigm, within a robust structure and collaborative environment which includes world-leading research facilities and support networks.