1. Solar Cells and Photonics Research Laboratory, School of Chemistry, University of Hyderabad, Prof. C R Rao Road, Hyderabad-500046, Telangana State, India
2. Department of Physics, National Institute of Technology (NIT) Warangal-506004, Telangana State, India
3. Department of Physics, University College of Science, Osmania University Hyderabad-500007, Telangana State, India