1. Department of Electrical and Electronic Engineering, University of Dhaka, Dhaka 1000, Bangladesh
2. Semiconductor Technology Research Centre, University of Dhaka, Dhaka 1000, Bangladesh
3. Department of Physics, University of Dhaka, Dhaka1000, Bangladesh
4. Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka 1000, Bangladesh
5. Dhaka University Nanotechnology Center, University of Dhaka, Dhaka 1000, Bangladesh