All-polymer thin film transistors fabricated by high-resolution ink-jet printing

All-polymer thin film transistors (TFTs) are fabricated by ink-jet printing for the first time. Source/drain electrodes are printed using a conducting polymer (PEDOT) solution on substrates with patterned wetting-and-dewetting regions. A channel length down to 5 /spl mu/m has been achieved without short-circuits. The TFTs show a high mobility of 0.02 cm/sup 2//V/spl middot/s and on/off ratio of more than 10/sup 5/. These characteristics are equal or better than reference devices with gold electrodes. The fabrication of printed inverters is also demonstated, in which components such as gate electrodes, interconnections, via-holes or resistors, are patterned with the ink-jet technique.