1. Nano Optoelectronics Research Laboratory, School of Physics; Universiti Sains Malaysia; Minden Penang 11800 Malaysia
2. OSRAM Opto Semiconductors (Malaysia) Sdn. Bhd, Bayan Lepas Free Industrial Zone Phase 1; Bayan Lepas Penang 11900 Malaysia
3. OSRAM Opto Semiconductors GmbH, Leibnizstr.4; Regensburg 93055 Germany