A 20‐inch, largest OLED display in the world is demonstrated which is driven by “Super Amorphous Silicon” technology. It has been widely believed that the characteristics of amorphous silicon TFT is not sufficient to drive OLED display. This paper turns over the hypothesis to prove that amorphous silicon can be applied to the large active‐matrix driven displays. Novel approaches to enable amorphous silicon to drive bright and long life OLED display are shown to open a bright future to realize larger OLED televisions.

We developed highly reliable oxide semiconductor TFT for AM-OLED displays. Passivating films, source/drain metals, and the TFT structure were optimized with an eye to improving device reliability to provide a lifetime over 10 years. An 11.7-inch diagonal qHD AM-OLED display was demonstrated to provide applicable solution for a large size OLED and an ultra-high definition LCD TV mass-production.

Abstract— A high‐mobility and high‐reliability oxide thin‐film transistor (TFT) that uses In‐Sn‐Zn‐O (ITZO) as a channel material has been developed. The mobility was 30.9 cm2/V‐sec and the threshold voltage shift after 20,000 sec of a bias‐temperature‐stress (BTS) test (with a stress condition of Vg = 15 V, Vd = 15 V, and T = 50°C) was smaller than 0.1 V. In addition, a method of obtaining a stable enhancement‐type TFT, which realizes circuit integration for active‐matrix organic light‐emitting diode (AMOLED) displays has been developed.

We have developed a direct fabrication method of oxide TFT on a flexible substrate and a flexible color filter array (CFA) technology for white OLED. The oxide TFT is successfully integrated on the flexible substrate and the fabricated display achieved wide color gamut of NTSC (in CIE u'v' space) more than 100%. Display Size 9.9" Number of Pixels 960  RGBW  540 (qHD) Pixel Size 228 m  228 m Resolution 111 ppi Number of Colors 16,777,216 Operation Scheme 2Tr Thickness 110 m 74.1L / M. Noda Late-News Paper 998 • SID 2012 DIGEST ISSN 0097-966X/12/4302-0998-$1.00

Abstract— The stability and reliability of oxide‐semiconductor TFTs were investigated. The contact material to the oxide semiconductor affected the thermal stability of the TFT, and a molybdenum‐contact source/drain showed good stability. And the passivating film and TFT structure affected the stability against bias stress and humidity stress, and dc‐sputtered Al2O3 passivation and fully covered channel structure with an etching stopper or source/drain showed good reliability. Moreover, high photo‐stability was confirmed by the bias‐enhanced photo‐irradiation stress test. An 11.7‐in.‐diagonal qHD AMOLED display was demonstrated to provide an applicable solution for a large‐sized OLED and an ultra‐high‐definition LCD‐TV mass production.