1. Department of Physics, National Institute of Technology, Warangal, Telangana-506004, India
2. Solar cells and Photonics Research Laboratory, School of Chemistry, University of Hyderabad, Hyderabad, Telangana-500046, India
3. Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University, Jordanstown, Newtownabbey, Co. Antrim, BT370QB, UK
4. Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, Tamilnadu-603203, India