1. Advanced Semiconductor Materials and Devices Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India
2. Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India
3. Directorate of Research, Innovation and Development, Jaypee Institute of Information Technology, Noida, U.P. 201309, India
4. Nanoscale Research Facility, Indian Institute of Technology Delhi, New Delhi 110016, India