1. Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
2. Solar
Energy Research Institute of Singapore, National University of Singapore, 7 Engineering Drive 1, Singapore 117574
3. Department
of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912, United States
4. School
of Engineering, Brown University, 184 Hope Street, Providence, Rhode Island 02912, United States