1. Postgraduate Institute of Science, University of Peradeniya, Peradeniya 20400, Sri Lanka
2. Department of Physics, Faculty of Science, University of Peradeniya, Peradeniya 20400, Sri Lanka
3. Centre for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei
4. Department of Nano Science Technology, Faculty of Technology, Wayamba University of Sri Lanka, Kuliyapitiya 60200, Sri Lanka