1. Department of Materials Science & Engineering and SPECIFIC-IKC, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN, UK
2. IQE Silicon Compounds, Beech House, Pascal Close, St. Mellons, Cardiff CF3 0LW, UK
3. IQE Europe Ltd., Pascal Close, St. Mellons, Cardiff CF3 0LW, UK