1. School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, Nanyang Technological University, Singapore 639798, Singapore
2. Department of Electrical and Electronics Engineering, Department of Physics, and UNAM–Institute of Materials Science and Nanotechnology, Bilkent University, TR 06800 Ankara, Turkey
3. School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor, Malaysia