Active-matrix displays a step closer

Researchers at Philips Research Laboratories in Eindhoven have succeeded in making a 64-by-64-pixel display in which each pixel is driven by a thin-film transistor based on a polymer semiconductor.

This, claim Philips, heralds an important step towards the realisation of low-cost, all-polymer, flexible displays.

The breakthrough at Philips uses polymer electronics rather than conventional silicon-based technology to address active-matrix displays.

Its own thin-film transistor based on polymer semiconductors switches each of the 4096 pixels of the demonstrator display.

The display operates at switching frequencies as high as 100 Hz and in the demonstrator display, only the semiconductor part of the transistors consist of polymer whilst the transistors are made on a solid substrate.

The same group of researchers has already demonstrated all-polymer transistors on flexible substrates, and all-polymer thin-film transistors are currently being incorporated in the next prototype flexible display.

Philips claims the enormous advantage of a polymer-based active matrix is the lower-cost production method because fewer production steps and less stringent clean room circumstances are required.

Philips also claims that it may be possible, in principle, to print the switches on plastic foil in a reel-to-reel process resulting in large-scale production of matrix of switches.

On the web at www.research.philips.com