Novel Organic Field Effect Transistors via Nano-Modification

Abstract : In recent years, organic/polymer field-effect transistors (FETs) provide inherent advantages of low cost, large area fabrication, simple packing, and compatibility with flexible substrates. The performance of organic FETs is determined primarily by the field effect mobility of the carriers in the organic semiconductor layers and by the efficiency of injecting and extracting carriers at source and drain currents. For virtually all classes of organic semiconductors, the intrinsic carrier mobility depends on the degree of molecular ordering critically and the extent of the stacking in the material. Under these conditions, we propose to enhance carrier mobility by using two kinds of nano-scale films. One is to apply the photoalignment method on a nano-scale film to control the orientation of pentacene molecules as an active layer in the thin-film transistors with conspicuously anisotropic electrical characteristics. Another is to employ also a nano-scale film (polymer electrolyte) to control moving of ions in/out an active semiconductor, pentacene or conducting polymer, for improving carrier mobility. In this project, pentacene or a series of conducting polymers, such as the derivatives of PANI and P3HT will be patterned and manufactured in FETs. Nano-scale films including polyimide for photoalignment/ion beam treatment and polymer electrolyte for ion doped/dedoped modification are to achieve the high mobility.