To increase the fabrication yield of carbon nanotube (CNT) thin film transistors (TFTs) for use in displays, electronic circuits, sensors, memory chips, and other applications that are transitioning from rigid substrates, such as silicon and glass, to flexible substrates, the Chair of Display Technology at Universitaet Stuttgart in Stuttgart, Germany and Nano-Proprietary's subsidiary Applied Nanotech reported that they are working together to apply CNTs to the flexible electronics industry.

ANI and the Universitaet Stuttgart said they have worked together to increase the fabrication yield of CNT TFTs using ANI's printing-like method of CNT deposition, which exceed an on/off ratio of five orders of magnitude and achieve the electron mobility necessary for their use for low temperature plastic-based substrates.

In May, the Chair of Display Technology of Universitaet Stuttgart presented the world's first full colour active matrix LCD where ITO as transparent conductive film (TCF) was completely replaced by random CNTs networks. The display has a qVGA resolution (320xRGBx240) at 4" diagonal.

The CNT networks are deposited by spray coating from suspension, which replaces a costly vacuum process, the two parties noted, which demonstrates the applicability of CNTs as TCF in a state-of-the-art amorphous silicon active matrix process, as well as giving a great perspective for future flexible displays, since CNT networks are much more reliable in flexible applications than the amorphous ITO.

The complete display, including AM-backplane, colour filters, and a dedicated addressing system was developed designed and fabricated at the Universitaet of Stuttgart.

By Ann Steffora Mutschler, Senior Editor - Electronic News