High-performance Printed Organic Field-effect Transistors And Digital Circuits

Alan J.Heeger,Alan G.Mac Diarmid and Hideki Shirakawa reported a highly conductive polymer in 1977,which makes it possible to prepare organic polymer materials for solution processed electronic devices in large quantities and at low cost,e.g.,by printing processes.In the past three decades,organic electronic technology has achieved rapid development due to its great potential in large-area,flexible,environmentally friendly and low-cost electronic products.Organic field-effect transistors(OFETs)have become an important part.OFET can be used for display,sensing,solar cells,smart tags,memory,and more complex integrated circuit(IC)applications.At present,OFET manufacturing is mainly based on evaporation and lithography processes,but the most effective way to utilize the unique functions of organic electronics is based on printing processes.Therefore,printed electronic technology emerged accordingly.In this paper,high-performance printed OFETs and digital circuits are fabricated by printing.The research content of this paper includes the following two aspects:1.Among the existing printing technologies,the most prominent is the electro-fluid inkjet printing(E-jet)technology,which uses the effect of the Taylor cone to control the volume of inkjet ink droplets at the f L level,greatly improving the printing pattern resolution.This article uses E-jet printed source/drain electrodes to make top-contact OFETs.The sintering temperature of printed electrodes could be down to 80 ? because of the trace amount of solvent.The printed line width/spacing could be smaller than 5 ?m on organic semiconductor.A printable Ag ink consist of F4-TCNQ additive greatly improves the charge injection of the OFET,and thus the OFETs based on E-jet printed top electrodes with channel length less than 15 ?m show comparable performance with thermally evaporated electrodes.2.Various modern electronic devices are made towards integrated circuits and digital circuits.It is essential to develop facile,effective and low-cost manufacturing methods.This article chooses screen printing processes to print water-based polymers and then etching,patterning the organic semiconductor layer and the dielectric layer.The patterned substrate can be used to prepare the basic digital logic circuit modules: inverter and ring oscillator.The technology has a high success rate,which is suitable for large-scale production without requirement of high temperature or vacuum conditions.It can reduce energy loss,have flexible pattern design,and can provide new design ideas for integrated circuits.Open up possibilities for innovative printed integrated circuits for Io T,wearable medical monitoring and smart packaging.