1. Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
2. Department of Physics and the College of Semiconductor and Advanced Technology Research, National Sun Yat-sen University, Kaohsiung, Taiwan
3. Department of Materials and Optoelectronic Science, National Sun Yat-sen University, Kaohsiung, Taiwan
4. Advanced Process Research Division, AUO Corporation, Hsinchu, Taiwan
5. Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan