1. Department of Electrical and Electronics Engineering, Shiraz University of Technology, Shiraz 71555-313, Iran
2. Research Center for Design and Fabrication of Advanced Electronic Devices, Shiraz University of Technology, Shiraz 71555-313, Iran
3. Department of Electrical Engineering-MNS, University of Leuven, Leuven 3001, Belgium
4. Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz 71555-313, Iran