Definition of the performance of photovoltaics is normally reduced to the efficiency alone. However, this number contains no indication of key issues such as system component reliability, module stability or appropriate balance of system design -- all of which play a crucial role in determining the performance in terms of usability. The key indicator is the levelised cost of energy (LCOE). The main influences on this, and thus the viability of photovoltaic technologies, are not only in material science but also in the way systems behave in the long term, and the uncertainty in predicting their behaviour. The link between laboratory-based materials science and the LCOE is poorly understood, revealing gaps in scientific knowledge which will be filled by this project. The key outcome is improved understanding of the potential for deploying photovoltaics in different climatic zones. The biggest unknowns in the LCOE are: understanding of the stability and long-term performance of photovoltaic modules; how a holistic system performance can be described; and the uncertainty in life-time energy yield prediction. This is crucial, especially for newer thin film technologies, which have been shown to be more variable in degradation and often suffer inappropriate balance of system components. Close collaboration with manufacturers of thin film as well as crystalline silicon devices will ensure that these aspects are appropriately covered. Novel measurement and modelling approaches for the prediction of life-time energy yield of the modules will be developed and validated against realistic data in collected in different climatic zones. This will result in the development of accelerated test procedures. Uncertainty calculations will enable identification and minimisation of this, and thus reduce the LCOE. A holistic systems approach is taken, specifically looking at the effects of different inverters in different climates and the effects of the existing network infrastructure on energy performance. At the heart of this project is the development of models and their validation, all focused on predicting the lifetime energy yield. A measurement campaign will be undertaken using novel techniques to better monitor the long-term behaviour of modules. Detailed, spatially-resolved techniques will be developed and linked to finite element-based models. This then allows the development of improved accelerated tests to be linked to real environments. These models will be validated against modules measured in a variety of realistic deployments. Using a geographical information system, maps of environmental strains and expected degradation rates per year for the different technologies will be developed.The feedback from the grid is an often underestimated effect on photovoltaic system performance. Typically, the grid and power conditioning cause 5-10% losses in otherwise appropriately installed systems; in unfortunate cases this can rise to 60%. The underlying reasons need to be better understood, so specific models for the interaction with the grid and different control strategies will be developed with the overall aim to minimise these loss effects.This project will be crucial for both the UK and India to translate their ambitious installation plans into reality as it will deliver the tools required to plan the viability of installations via geographical information systems, underpinned by a robust science base. This will aid decisions on the use of appropriate photovoltaic technology for a given site, to include both the modules themselves and other system components, to maximise cost-effectiveness and reliability.

Investment in innovation and research in Information and Communications Technology (ICT) is essential in order to foster social and economic inclusion, better public services, and improvements in the quality of life for citizens. The key purpose of our Network is to strengthen such investment in the area of Next Generation Telecommunications Networks in support of the Digital Economy. Such aspirations are pivotal for social inclusion and economic prosperity in both the UK and India. Within the UK, the situation is improving, but according to Ofcom's recent report on the Nations and Regions 2007, more work needs to be done to ensure that the benefits of the Digital Economy are accessible and affordable to all of its citizens. With a growing middle class that now numbers nearly 400 million people, India's electronics equipment consumption, estimated at $28.2 billion in 2005, is expected to reach $363 billion by 2015. Domestic production totalled $10.99 billion in 2005 and is projected at $155 billion in 2015, according to ISA estimates, thanks to such drivers as mobile phones, wireless equipment, set-tops and smart-card terminals. These developments, and the priorities of government to raise educational and business standards and address social and economic deprivation, are driving the pressure on the enabling communications and service providers to come up with cost-effective solutions that can be rolled out at scale in support of the digital economy in both countries.Within our proposed Network, we will address a number of themes that will contribute to the development and deployment of Next Generation Converged Networks. These themes build on the strengths of our Network Members and also provide the greatest opportunities for the consideration of Technology Demonstrators that will underpin the development of government policies and initiatives for both Rural and Urban Digital Economy programmes in both UK and India.For the past two years, under the invitation of EPSRC and the British High Commission in Delhi, Professor Parr has established a UK-India Advisory Group (see Letters of Support from British High Commission Personnel in India). This group has been formulating a development plan between the two nations, involving an agenda of activities within the context of Next Generation Networking; the purpose is to encourage the development of real and meaningful collaborations that will be internationally leading and economically relevant to both the UK and India. Overall, the intention is the establishment of a joint Indo-UK Virtual Centre of Excellence that will address the domain of Next Generation Networking for the benefit of both nations. The provision of core funding through this EPSRC INTERACT Programme is critical to the creation of our Network and to enable our plans to go forward on a sure footing for the future.

When an impurity atom in a semiconductor crystal has more (or fewer) valence electrons than the atom it replaces, it can donate one or more electrons to (or accept them from) the crystal lattice. The deliberate addition of such impurities, called dopants, is the traditional means of generating mobile charge carriers (negatively-charged electrons or positively-charged holes) within semiconductor devices, including the silicon-based metal-oxide-semiconductor field-effect transistors (MOSFETs) and compound semiconductor high-electron-mobility transistors (HEMTs) ubiquitous in modern electronics. High-mobility, gallium-arsenide-based HEMTs in particular, which can be made from ultrahigh-purity wafers grown by molecular beam epitaxy (MBE), have also been instrumental in the discoveries of new physics, including the fractional quantum Hall (FQH) effect, microwave-induced resistance oscillations, Wigner solid phases in magnetic field, ballistic transport and conductance quantisation in one-dimensional channels, single-electron quantum dots, Kondo physics, spin-based solid-state qubits, possible excitonic superfluidity in double-quantum-well structures, and possible non-Abelian statistics in certain novel FQH states. Even with the technique of modulation doping, where dopants are placed far away from the conducting channel, disorder due to the ionised dopants can still be felt by the carriers in a high-purity wafer, and this disorder can interfere with phenomena being studied. However, these intentional dopants are not necessary if one uses instead an external electric field to electrostatically induce a two-dimensional electron gas (2DEG) or hole gas (2DHG) at the semiconductor heterointerface. This electric field can be applied with electrostatic gates on the front and/or back side of devices. Although the proof-of-principle demonstration of undoped devices (which required only one working device) was reported more than eighteen years ago by Bell Labs (USA), the complex cleanroom fabrication process and the ensuing very low yield of working devices have prevented the use of undoped devices from becoming mainstream. Over the last three years, our group has made a number of technological breakthroughs which allow a 90+% yield of working devices, including Hall bars and nanostructures (e.g., quantum dots). This yield is now high enough to have research projects depend on a steady, reliable supply of high-quality samples. To capitalise on this success, we propose to combine our ability to fabricate such devices on demand with our expertise in MBE semiconductor wafer growth and millikelvin temperature measurements to further progress on two of the topics listed above, the fractional quantum hall effect and spin-based solid-state qubits. Many "exotic" FQH states present in the second Landau level do not fit the Laughlin/Jain theory which describes "conventional" FQH states, and are particularly sensitive to dopant-induced disorder. Our experimental programme will shed light on the nature of these states, particularly the famous state at filling factor 5/2 and its possible non-Abelian properties. Gate-defined electron spin qubits in GaAs were once amongst the forerunner systems for the realisation of a quantum computer. However, this system suffers from the presence of hyperfine interactions and charge noise, both of which cause spin decoherence on timescales too short for a practical quantum computer. Our experimental programme will demonstrate how both hyperfine interactions and charge noise are significantly reduced when gate-defined double quantum dots are fabricated from undoped 2DHGs. Our proposed work will yield fundamental insights into physical phenomena not easily accessible using even the highest quality doped heterostructures.