1. Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
2. Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
3. Advanced Optoelectronics Technology Center, National Cheng Kung University, Tainan 70101, Taiwan
4. Department of Photonics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
5. Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
6. Department of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China
7. New Technology Development, HannStar Display Corporation, Tainan 741, Taiwan