1. Division
of Physics and Applied Physics, School of Physical and Mathematical
Sciences, Nanyang Technological University, Singapore 637371
2. LUMINOUS!
Center of Excellence for Semiconductor Lighting and Displays, TPI-The
Photonics Institute, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798
3. China Academy of Engineering Physics, Mianyang 621900, China
4. Department
of Electrical and Electronics Engineering, Department of Physics,
UNAM−Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey
5. NOVITAS,
Nanoelectronics Centre of Excellence, School of Electrical and Electronic
Engineering, Nanyang Technological University, Singapore 639798