1. Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA
2. Institute of Physics, Federal University of Bahia, Campus Universitário da Federação, Barão de Jeremoabo St., 40170-115 Salvador, BA, Brazil
3. Holonyak Micro and Nanotechnology Lab, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA
4. Department of Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, Ohio 45221, USA
5. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS, United Kingdom
6. DexMat, Inc., 5000 Gulf Fwy, Bldg 5, Rm 146, Houston, Texas 77023, USA
7. Science, Math and Technology, Singapore University of Technology and Design, 8 Somapah Rd., Singapore 487372
8. Department of Chemical and Biomolecular Engineering and Department of Chemistry, The Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, Texas 77005, USA