1. Institute of Materials Research
and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602, Republic
of Singapore
2. Department
of Electrical and
Computer Engineering, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 117576, Republic of Singapore
3. Chemistry and Physics of Materials
Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore
-560064,
India