Toppan Flexible Electronic Paper Driven by Oxide Semiconductor TFT
According to their press release
Toppan Printing Co., Ltd. has developed an amorphous oxide semiconductor thin film transistor (TFT) array and succeeded in driving an electrophoretic E Ink front panel laminate to fabricate a prototype flexible electronic paper display.
Apparently the amorphous InGaZnO semiconductor used here has a higher charge carrier mobility (> 5cm^2/Vs) than a-Si and can be deposited at room temperature. Flexible TFTs based on a-InGaZnO were first demonstrated by Professor Hosono and coworkers at Tokyo Institute of Technology (Nomura et al, Nature 432, 488 (2004)).
All layers of the 2 inch diagonal (80 x 60 pixels) display were deposited onto the flexible PEN substrate by sputtering, but Toppan plans to deposit and pattern some of the layers by printing.
Toppan plans to develop flexible TFTs with goals to commercialize thin, lightweight and flexible displays such as electronic paper, starting with a practical prototype display in fiscal 2008. In parallel, we aim to introduce printing methods into the fabrication process of flexible TFTs for simplification and cost reduction.
Note: This research was reported at IDW’05 as EP2-4L (International Display Workshop, Dec.6-9, 2005, Takamatsu, Japan)