Step toward robust and reliable amorphous polymer field-effect transistors and logic functions made by the use of roll to roll compatible printing processes

Printed organic electronic is believed to be one of the next major technological breakthroughs in the field of microelectronic. The use of high throughput standard graphic arts printing to process organic field-effect transistors (OFETs) opens promising perspectives for low cost, large area and flexible circuits. Nevertheless, these techniques are commonly known to produce relatively thick (>1 mu m) layers and to require complex inks formulations composed of several additives. In this paper, we demonstrate that screen printing and gravure printing may be highly versatile and could be well appropriate to deposit organic semi-conducting layers. These fast "single step" processes combined with amorphous semi-conducting polymer give thin, uniform and reproducible layers. The performances of printed or spin-coated films are similar and lead to robust and reliable full printed transistors and logic functions. Moreover, the capability of screen printing and gravure to deposit small patterns of semiconductor is discussed. Lines and spaces down to 500 mu m are reported without specific inks and tools optimizations. (C) 2009 Elsevier B.V. All rights reserved.