1. Department of Materials Science & NanoEngineering, Rice University, Houston, Texas 77005, United States
2. NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore
3. Department of Chemistry, Rice University, Houston, Texas 77005, United States
4. School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
5. CNRS-International-NTU-Thales Research Alliance (CINTRA), Nanyang Technological University, 639798 Singapore