Printing of polymer thin-film transistors for active-matrix-display applications

We present a process for active-matrix flat-panel-display manufacture based on solution processing and printing of polymer thin-film transistors. In this process, transistors are fabricated using soluble semiconducting, conducting, and dielectric polymer materials. Accurate definition of the transistor channel and other circuit components are achieved by direct ink-jet printing combined with surface-energy patterning. We have used this process to create 4800-pixel 50-dpi active-matrix backplanes. These backplanes were combined with polymer-dispersed liquid crystal to create the first ink-jet-printed active-matrix displays. Our process is, in principle, environmentally friendly, low temperature, compatible with flexible substrates, cost effective, and advantageous for short-run length and large display sizes. As well as polymer-dispersed liquid crystal, this technology is applicable to conventional liquid-crystal and electrophoretic display effects.