1. Organic Nano-Piezoelectric Device Laboratory, Department of Physics, Jadavpur University, Kolkata 700032, India
2. Applied Physics and Sensor Technology, Brandenburg University of Technology Cottbus−Senftenberg, Konrad-Wachsmann-Allee 17, 03046 Cottbus, Germany
3. Applied Physics and Semiconductor Spectroscopy, Brandenburg University of Technology Cottbus−Senftenberg, Konrad-Zuse-Straße 1, 03046 Cottbus, Germany
4. Institute of Nano Science & Technology, Habitat Centre, Phase 10, Sector 64, Mohali 160062, India