1. Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
2. Department of Physics, North Carolina State University, 2401 Stinson Drive, Raleigh, North Carolina 27695-8202, United States
3. Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way, Raleigh, North Carolina 27695-7907, United States