[SID] Toshiba Develops Flexible OLED Panel

May 23, 2011
Naoki Tanaka, Tech-On!
The prototype showed in the author's interview
The prototype showed in the author's interview
[ If it clicks, the expanded picture will open ]

Toshiba Corp developed a flexible OLED panel driven by oxide semiconductor TFTs (thin-film transistors) and announced it at the 49th SID International Symposium, Seminar & Exhibition (SID 2011).

By lowering the highest process temperature in the formation of oxide TFTs to 200°C, Toshiba enabled to use plastic substrates. In the author's interview after the announcement, the company showed a prototype using a plastic substrate.

The prototyped flexible OLED panel has a screen size of 3 inches and a pixel count of 160 x 120. To realize color display, Toshiba formed white OLED elements and color filters on oxide TFTs.

The oxide semiconductor constituting the TFTs is indium gallium zinc oxide (IGZO, In-Ga-Zn-O). The gate driver circuit was also formed on the plastic substrate by using oxide TFTs. The OLED element is a bottom-emission type, and the TFT element has a bottom-gate structure (the etch-stopper method).