AlGaN/GaN high electron mobility transistors (HEMTs) are a key enabling technology for future power conditioning applications in the low carbon economy, and for high efficiency military and civilian microwave systems. GaN-on-Si is highly attractive as a low cost, medium performance technology platform which has been proved to be usable even up to the W-band. The main down-sides of Si are the low bandgap and hence resistive lossy substrate especially at modest elevated temperatures, the vulnerability of the Si to unintentional doping with gallium during epitaxy causing RF losses, and the somewhat restricted power handling resulting from the relatively low thermal conductivity of the Si compared to the 4" SiC growth substrates currently used. However the cost benefits are dramatic allowing 6" or even 8" high volume wafer processing. 6" GaN-on-Si epitaxy is already available driven by the emerging GaN-on-Si power switch market, however it is optimised for high voltage, switched-mode operation. Improved RF power amplifier (PA) efficiency using GaN-on-Si, which is the focus of this proposal, would reduce the transistor temperature rise, reduce the substrate losses and deliver a low-cost high-performance technology as it would reduce the transistor temperature rise and reduce the substrate losses. The advance that is required is an optimised RF specific GaN-on-Si transistor architecture, which requires detailed understanding of electronic traps introduced into the GaN buffer of these devices by iron, carbon and carbon/iron co-doping, which is presently lacking. The key aim of this proposal is to control and model the device capacitances and conductances using novel epitaxial design of the GaN buffer, as this is key to delivering improved efficiency, gain and linearity in RF amplifiers.

This is a proposal for advanced crystal growth equipment to enable the UK to take a lead in important areas of Quantum Technologies. It will enable the growth of nanometre-scale semiconductor quantum dots with world-leading properties. These properties include emission limited only by fundamental properties of the dots unaffected by the surrounding environment, and ordered arrays of dots, critical to enable scale-up and to translate the much excellent science of quantum dots to highly competitive Quantum Technologies. The Quantum Technology applications rely on purely quantum mechanical principles such as superposition, where a system can be in two states at the same time, and entanglement where an operation at one spatial location influences another remotely, without there being any direct connection between them. Quantum dots are extremely well suited to exploiting these quantum mechanical effects (sometimes termed 'Quantum 2'). The favourable properties of III-V semiconductor quantum dots include on-demand single and entangled photon emission, ready incorporation in cavities, very long coherence and compatibility with well-developed III-V semiconductor processing technology. III-V semiconductors are familiar in everyday life as the basis of light emitting diodes, internet data transmission, and laser disk storage to name just a few. Here we turn the favourable III-V properties to enable new applications in Quantum Technologies, including as sources for secure Quantum Cryptography, quantum relays for Quantum Communications, integrated entangled sources for Quantum Cryptography and sensing, and longer-term opportunities for memories and spin chains for Quantum Networks. The crystal growth equipment, an Epitaxy Cluster Tool, is comprised of two principal chambers, one dedicated solely to the growth of highest quality quantum dots, and the second to the advanced processing of structured templates for growth of arrays of dots with pre-determined location, enabling the realisation of very high brightness sources of single photons and of arrays essential for scale-up. The two principal chambers will be connected together by an automated loading, transfer and analysis chamber, enabling high throughput of the system, and furthermore ensuring that only highest cleanliness wafers are transferred to the ultrahigh purity chamber. The Cluster Tool constitutes an integrated suite of growth, analysis and processing features. It will provide the UK with unique experimental infrastructure to take a leading position in the translation of quantum-dot-based science into Quantum Technologies.

N/A - see case for support

This proposal seeks funding to deliver enhanced capability for characterising and assessing advanced nanomaterials using three complementary, leading edge techniques: Field-emission microprobe (EPMA), combined Raman/multiphoton confocal microscope (Raman/MP) and small angle X-ray scattering (SAXS). This suite of equipment will be used to generate a step-change in nanoanalysis capability for a multi-disciplinary team of researchers who together form a key part of Strathclyde's new Technology and Innovation Centre (TIC). The equipment will support an extensive research portfolio with an emphasis on functional materials and healthcare applications. The requested equipment suite will enable Strathclyde and other UK academics to partner with other world-leading groups having complementary analytical facilities, thereby creating an international collaborative network of non-duplicated facilities for trans-national access. Moreover the equipment will generate new research opportunities in advanced materials science in partnership with the National Physical Laboratory, UK industry and academia.