Leading on from the highly acclaimed TSB-funded Project TOPLESS, we will work towards developing a materials set of polymers, all of which posses high triplet energies, which will allow all-phosphorescent, multi-layer polymer light-emitting devices (PLEDs) to be made specifically for use in solid-state lighting applications. Project TOPLESS, lead by Thorn Lighting with CDT and Durham has demonstrated that all-solution-processed PLED panels giving high quality white light at 25 lm/W without out-coupling can be readily made. The key here was the use of a fluorescent blue emitter along with phosphorescent green and red emitters to generate a tri-white spectrum. Calculations show that to make a further step change in efficiency, towards 40 lm/W or more, devices must be made utilising all-phosphorescent emitters. This dictates radical changes to the materials used in the multi-layer device structure, such that all the layers (polymers) must have sufficiently high triplet energies to prevent quenching of the blue phosphor. Such polymers do not yet exist. In this research project we take the first steps towards the design and synthesis of high triplet hole-transport, electron-transport and ambipolar (emitter host) materials. Materials will be fully characterised using a range of spectroscopic techniques. Devices will be fabricated and tested, leading on to new generations of materials. Key building blocks have been identified as starting points for this work and several promising motifs have been patented with Thorn Lighting (via Project TOPLESS and through other work at Durham). During the project we shall not make the emitters themselves; a new family of blue phosphors has been developed in Durham, as part of the TOPLESS project and new phosphors will be explored in collaboration with Dr J. A. G. Williams in Durham. Here we focus on the materials for hosts and transport layers for blue phosphors. Along with the design, synthesis and characterisation of new materials, we will explore device architectures best suited to high efficiency blue and white emission, exploiting multi-layer fabrication techniques developed in Durham (also recently patented). Further, detailed analysis of triplet exciton migration within multilayer structures will be made using both novel spectroscopy (developed in Durham) and modelling developed in a collaboration with Kodak and continued in collaboration with Prof Chris Winscom at Brunel University. This will enable us to investigate ideas of triplet exciton confinement within an emitter layer such that transport layers do not act as quenching sites. This would then make the design and synthesis of transport layers much more simple. Critical decision points following the progress of this work will be made by the management team at the end of the first year of the project.We aim to fast-track new industrialisation of materials made during this project. This will be achieved by input from Thorn on the project management team and the fact that this project will run in parallel with the successor to Project TOPLESS, namely Project TOPDRAWER. Promising new materials sets can be rapidly feed into Project TOPDRAWER for printing trials and development of an all-phosphorescent white PLED panel. The development of host materials for blue phosphors is so vital to Thorn Lighting's plans to commercialise organic solid-state lighting that they will accelerate research in this area by giving the strongest possible support to this project. They have committed to support this project by contributing 150,000 to the cost of the project, reducing the EPSRC's funding by this amount.

We are on the verge of a global revolution in lighting, as efficient and robust light emitting diode (LED) based 'solid state lighting' (SSL) progressively replaces traditional incandescent and even fluorescent lamps and finds its way into new areas including signage, illumination, signalling, consumer electronics, building infrastructure, displays, clothing, avionics, automotive, sub-marine applications, medical prosthetics and so on. This technology has tended to be viewed, so far, primarily as a way to improve energy- and spectral-efficiency, but what has been relatively little studied or appreciated is its profound implications for the future of communications. We envisage the tremendous prospect of an entirely new form of high bandwidth communications infrastructure to complement, enhance and in some cases supercede existing systems. This LED-based technology will utilise the visible spectrum, largely unused for communications at present and more than 10,000 broader than the entire microwave spectrum. This promises to help address the 'looming spectral crisis' in RF wireless communications and to permit deployment in situations where RF is either not applicable (e.g. in underwater applications) or undesirable (e.g. aircraft, ships, hospital surgeries), but the implications are more fundamental even than that. The key point, in our view, is that lighting, display, communications and sensing functions can be combined, leading to new concepts of 'data through illumination' and 'data through displays'. Imagine, for example, a 'smart room', where 'universal illuminators' provide high-bandwidth communications, sensors monitoring the environment and people within it, provide positioning information and display functions, and monitor the quality of the light. Imagine novel forms of personal communications system that combine display functions and video with multiple, high-bandwidth communications channels. These could be through mobile personal communicators (developments of mobile phones or personal digital assistants) or even wearable and mechanically flexible displays. Our ambitious programme seeks to explore this transformative view of communications in an imaginative and foresighted way. The vision is built on the unique capabilities of gallium nitride (GaN) optoelectronics to combine optical communications with lighting functions, and especially on the capability of the technology to implement new forms of spatial multiplexing, where individual elements in high-density arrays of LEDs provide independent communications channels, but can combine as displays. We envisage ultra-high data density - potentially Tb/s/mm2 - arrays of LEDs in compact and versatile forms, and will develop novel transceiver technology on this basis on both mechancially rigid and mechanically flexible substrates. We will explore the implications of this approach for multi-channel waveguide and free-space optical communications, establishing guidelines and fundamental assessments of performance which will be of long-term significance to this new form of communications.

The CBES group at the UCL Bartlett School of Graduate Studies received its Platform Award in 2006 and the funding has facilitated a period of sustained success. Platform funding has been of critical value in helping us to retain key staff, to innovate and in providing the flexibility to be adventurous. We have also been able to enhance our knowledge exchange/transfer work and international collaboration. This has been reflected in the quality, growth and range of our activities. The Platform funding thus enabled us to establish a multi-disciplinary, world-leading research group which has dramatically increased in size, resulted in world leading academic publications, seeded a new Institute (Energy), developed new methods of interdisciplinary and systems working and won international prizes. CBES was submitted to and awarded the highest percentage (35%) of world leading rated researchers of any UK university in the 2008 Research Assessment Exercise (RAE) - Architecture and the Built Environment Panel. Building on the work directly supported or indirectly facilitated by the current Platform Grant, and also responding to new opportunities, the strategic direction of this continuation proposal represents a step change for CBES. During the period of the current Platform Grant, CBES was primarily interested in developing multi-disciplinary solutions to the practical problems of designing, constructing and managing environments within and around buildings. In the next quinquennium we will strengthen our world-leading position. We propose a strategic programme of activity in a timely new research direction - the unintended consequences of decarbonising the built environment . We aim to transform understanding of this urgent issue that will have enormous impact internationally.In order to predict the possible future states of such a complex socio-technical system, conventional scientific approaches that may have been appropriate for systems capable of being analysed into simple components are no longer applicable. Instead, we need to bring radically new approaches and ways of thinking to bear. We need to develop and extend our multi- and inter- disciplinary ways of working and be informed by modern complexity science. The initial Platform grant has helped set up a group that includes building scientists, heritage scientists, economists, systems modellers and social scientists. The renewal will enable the group to focus on this urgent problem, to develop appropriate research methods and help develop real-world solutions within the required timescale. The number of Investigators has increased from 11 at the start of the existing Platform Grant to 13 in the renewal - a vital expansion to enable the inclusion of a wider range of disciplines. Nevertheless, facilitated by Platform funding, we will now need to form a whole new set of additional alliances to support the development of our proposed work.One of the key achievements of the current Platform Grant has been the spinning off of the newly formed UCL Energy Institute (EI). CBES is thus ideally placed to benefit from the extensive and diverse range of energy demand reduction work at the EI. However, the EI is not funded to study unintended consequences and this Platform renewal will thus perfectly complement EI activity. Via Platform funding and in partnership with the EI, CBES aims to develop a new concentration of world-leading research excellence in this field. We will establish a regional hub for research collaboration with local universities which will ensure that benefits from Platform funding are felt more widely than UCL alone.