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Unformatted text preview: Flexible full color organic light-emitting diode display on polyimide plastic substrate driven by amorphous indium gallium zinc oxide thin-film transistors Jin-Seong Park, a ! Tae-Woong Kim, Denis Stryakhilev, Jae-Sup Lee, Sung-Guk An, Yong-Shin Pyo, Dong-Bum Lee, Yeon Gon Mo, Dong-Un Jin, b ! and Ho Kyoon Chung Technology Center, Samsung Mobile Display Co. LTD, 428-5, Nongseo-Dong, Kiheung-Ku, Yongin-City, Kyungki-Do 449-577, Republic of Korea s Received 25 May 2009; accepted 6 June 2009; published online 6 July 2009 d We have fabricated 6.5 in. flexible full-color top-emission active matrix organic light-emitting diode display on a polyimide s PI d substrate driven amorphous indium gallium zinc oxide thin-film transistors s a-IGZO TFTs d . The a-IGZO TFTs exhibited field-effect mobility s m FE d of 15.1 cm 2 / V s, subthreshold slope of 0.25 V/dec, threshold voltage s V TH d of 0.9 V. The electrical characteristics of TFTs on PI substrate, including a bias-stress instability after 1 h long gate bias at 15 V, were indistinguishable from those on glass substrate and showed high degree of spatial uniformity. TFT samples on 10 m m thick PI substrate withstood bending down to R =3 mm under tension and compression without any performance degradation. © 2009 American Institute of Physics . f DOI: 10.1063/1.3159832 g Active matrix organic light-emitting diodes s AMOLEDs d have attracted considerable interest in the emerging electronic device market because they are thinner, faster, and more power efficient than active matrix liquid- crystal displays. Some researchers have demonstrated flex- ible AMOLED with various thin film transistors s TFTs d . 1 – 3 To realize flexible AMOLEDs backplane, two key require- ments should first be satisfied or/and resolved during fabri- cation. The first requirement is to fabricate a uniform and stable TFT backplane with good electrical performance and stability. Conventional amorphous silicon s a-Si d TFTs ex- hibit uniform electrical characteristics, even over eighth gen- eration substrate s 2.2 3 2.5 m 2 d . However, their low field- effect mobility s, 0.5 cm 2 / V s d and instability under bias stress constitute considerable problems for application in AMOLED. 4 , 5 On the other hand, low temperature polycrys- talline silicon TFTs exhibit high field-effect mobility s . 50 cm 2 / V s d and stable electrical performance in OLED driving devices. However, there are still significant issues with poor uniformity over a large area and high process tem- perature s, 500 °C d during silicon crystallization. Recently, amorphous indium gallium zinc oxide s a-IGZO d TFT tech- nology has been reported to deliver excellent uniformity, good device performance s mobility . 10 cm 2 / V s d , and electrical stability in a simple fabrication process....
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- Spring '08
- pH, Glass, Light-emitting diode, Orders of magnitude, Glass transition, TFTs