1. Department of Physics, National Institute of Technology Durgapur, Durgapur 713209, West Bengal, India
2. Department of Physics, Banwarilal Bhalotia College, Asansol 713303, West Bengal, India
3. Centre of Organic Spintronics and Optoelectronic Devices, Kazi Nazrul University, Asansol 713340, West Bengal, India