[1] Natl Tsing Hua Univ, Inst Elect Engn, Hsinchu 300, Taiwan
[2] Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 804, Taiwan
[3] Natl Sun Yat Sen Univ, Inst Electroopt Engn, Kaohsiung 804, Taiwan
[4] Natl Sun Yat Sen Univ, Ctr Nanosci & Nanotechnol, Kaohsiung 804, Taiwan
[5] Natl Chiao Tung Univ, Dept Photon, Hsinchu 300, Taiwan
[6] Natl Chiao Tung Univ, Display Inst, Hsinchu 300, Taiwan
[7] Natl Tsing Hua Univ, Dept Engn & Syst Sci, Hsinchu 300, Taiwan
[8] Natl Sun Yat Sen Univ, Inst Mat Sci & Engn, Kaohsiung 804, Taiwan
[9] Natl Chiao Tung Univ, Inst Elect, Hsinchu 300, Taiwan