1. Department of Polymer Chemistry and Technology, Kaunas University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
2. Materials Science and Engineering and Physics, Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei10617, Taiwan
3. Department of Opto-Electronics Engineering, National Dong Hwa University, Shoufeng, Hualien974301, Taiwan
4. Research Center for Applied Sciences, Academia Sinica, Taipei11529, Taiwan
5. Department of Electrical Engineering, Yuan Ze University, Chung-Li32003, Taiwan