Solution-based hybrid printing process for tiny channel length of organic transistors

Abstract

Inkjet printing technique has been studying intensively on organic electronics, but its resolution is limited to about 20 to 50 μm due to the nozzle size and the interaction between the ink and substrates. In order to reduce the patterning feature of IJP, we use the contact printing as an auxiliary process to pre-define the desired deposition pattern. By use of the wetting and the dewetting surface properties, the inkjet printed ink will self-align to the wetting surface to afford tiny feature. In this paper, Poly[3,4-(ethylenedioxy)thiophene] (PEDOT) was selected and patterned as electrodes of organic transistors. Octadecyltrichlorosilane (OTS) thin layer was used as the surface modifier. The minimum channel length can achieve to about 5 μm or so. The field-effect mobility of 0.001 cm2/V-s and on/off current ratios of 103 were obtained in the ploy(3-hexylthiophene) organic thin film transistors fabricated by this proposed process.