1. Centre for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Tungku Link, Gadong BE1410, Negara Brunei Darussalam
2. Department of Physics, Fu Jen Catholic University, New Taipei City 242, Taiwan
3. Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, Taiwan
4. Institute of Optoelectronic Sciences, National Taiwan Ocean University, No. 2 Pei-Ning Road, 202 Keelung, Taiwan
5. Institute of Physics, Academia Sinica, Taipei 11529, Taiwan