1. Display Device Lab.; Samsung Advanced Institute of Technology; Yongin-Si Gyeonggi-do 446-712 Korea
2. Department of Organic Materials and Fiber Engineering; Soongsil University; Seoul 156-743 Korea
3. Flexible Display Research Center; Korea Electronics Technology Institute; Seongnam-si Gyeonggi-do 463-816 Korea
4. Institute of Physics and Applied Physic; Yonsei University; Seoul 120-749 Korea
5. Department of Information and Communication Engineering; Daegu Gyeongbuk Institute of Science and Technology (DGIST); Daegu 711-873 Korea