1. Department of Physics, School of Advanced Sciences, VIT, Vellore, 632014, India
2. Department of Physics, G.T.N Arts College (Affiliated to Madurai Kamaraj University), Dindigul, India
3. Functional Nanomaterials & Devices Lab, Centre for Nanotechnology & Advanced Biomaterials and School of Electrical & Electronics Engineering, SASTRA Deemed to be University, Thanjavur, 613 401, India
4. Centre for Nanotechnology Research, VIT, Vellore, 632014, India