Investigation On The Interfacial Electrical Properties Of Small Molecular Field-effect Transistor

Organic field-effect transistors(OFETs) has attracted widespread attention of academia.Compared with inorganic field-effect transistors, organic field-effect transistors have a series of advantages: highly integrated,operation speed, low-power operation, capable of low temperature processing, easy-to-large-scale production.Currently, the performance of organic field-effect transistors has been greatly improved,but for its theory and material structure there are still many issues to be further explored.In this paper, starting from the electrical properties of inorganic/organic interface,studied with field-effect transistors interface transmission and electrode materials selection, mainly including two aspects as follows:1、Studied three kinds of OFETs with Au, Cu Ox, Au-Cu Ox as their electrodes respectively.Then, calculated their mobilities.Experimental data showed that the performance of Au-Cu Ox electrode contact-type device was the best. Cu Ox electrode could reduce the injection barrier and induce hole doping to the pentacene channel,which favor easier hole transport. Encapsulate the thin Cu Ox inter layer with a top Au layer would get a further improved mobility and reduced contact resistance.2 、 Two kinds of devices were studied.The different kinds of structures were Au/Cu Pc/Si O2/n++Si and Au/Cu Pc/ATO/n++Si,measured by Kelvin probe force microscope.Experimental results showed that the performance of Au/Cu Pc/ATO/n++Si device was better than Au/Cu Pc/Si O2/n++Si device.The reasons were that high-k ATO film caused the trap DOS in Cu Pc film band gap substantially decreased to7×1017cm-3,while improved the crystallinity of Cu Pc.