Fabrication of Polymer-Based Transistors with Carbon Nanotube Source Drain Electrodes Using Softlithography Techniques

摘要

In this study, we have developed the multilayer deposition and patterning processes with a resolution of 1 urn for fabricating polymer-based organic field effect transistors (p-OFETs) based on vacuum-free, solution processable softlithography techniques. We have used regioregular poly(3-hexylthiophene) (P3HT) as the soluble polymer semiconductor, and poly(methyl methacrylate) (PMMA) and polyimide as the soluble and insoluble polymer gate insulators, respectively. We have used multiwalled carbon nanotubes (MWNTs) as the printed source-drain (S-D) electrodes in order to fabricate vacuum-free, all printed OFETs. The p-OFETs with MWNT S-D electrodes exhibit higher hole mobility and on/off ratio than the devices with vacuum-evaporated Au electrodes, probably owing to the better contact of the electrode interface and damage-free transfer of electrodes onto the gate insulator. The mobility was further improved by the crystallization of the P3HT film after heat treatment prior to the pattern transfer of P3HT.