1. School of Materials Science and Engineering, The University of New South Wales (UNSW) Sydney, Sydney, NSW 2052, Australia
2. Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, India
3. Electron Microscope Unit, UNSW Sydney, Sydney, NSW 2052, Australia
4. School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2008, Australia
5. School of Chemical Engineering, UNSW Sydney, Sydeny, NSW 2052, Australia
6. ARC Centre of Excellence in Future Low-Energy Electronics Technologies, UNSW Sydney, Sydney, NSW 2052, Australia
7. College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA 5042, Australia
8. Flinders Institute for Nanoscale Science and Technology, Flinders University, Adelaide, SA 5042, Australia