3.4-Inch Quarter High Definition Flexible Active Matrix Organic Light Emitting Display with Oxide Thin Film Transistor

• Published in: Japanese Journal of Applied Physics 2011-03, Vol.50 (3), p.03CC06-03CC06-4
• Main Authors: Hatano, Kaoru, Chida, Akihiro, Okano, Tatsuya, Sugisawa, Nozomu, Inoue, Tatsunori, Seo, Satoshi, Suzuki, Kunihiko, Oikawa, Yoshiaki, Miyake, Hiroyuki, Koyama, Jun, Yamazaki, Shunpei, Eguchi, Shingo, Katayama, Masahiro, Sakakura, Masayuki
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.50.03CC06

In this paper, we report a 3.4-in. flexible active matrix organic light emitting display (AMOLED) display with remarkably high definition (quarter high definition: QHD) in which oxide thin film transistors (TFTs) are used. We have developed a transfer technology in which a TFT array formed on a glass substrate is separated from the substrate by physical force and then attached to a flexible plastic substrate. Unlike a normal process in which a TFT array is directly fabricated on a thin plastic substrate, our transfer technology permits a high integration of high performance TFTs, such as low-temperature polycrystalline silicon TFTs (LTPS TFTs) and oxide TFTs, on a plastic substrate, because a flat, rigid, and thermally-stable glass substrate can be used in the TFT fabrication process in our transfer technology. As a result, this technology realized an oxide TFT array for an AMOLED on a plastic substrate. Furthermore, in order to achieve a high-definition AMOLED, color filters were incorporated in the TFT array and a white organic light-emitting diode (OLED) was combined. One of the features of this device is that the whole body of the device can be bent freely because a source driver and a gate driver can be integrated on the substrate due to the high mobility of an oxide TFT. This feature means "true" flexibility.