The Preparation of High Performance Pentacene Transistors and Their Application in Flat Display
|School||Hefei University of Technology|
|Course||Precision instruments and machinery|
|Keywords||pentecene surface modified flexible organic thin-film transistors(OTFTs) electrical properties|
Organic Thin-Film Transistor has been attracting much attention because of its lowproduction costs, simple processing technology. OTFT is regarded as an ideal candidateTFT, it has great application prospect in the field of flat display. In this paper, in order tomake OTFT driving OLED luminescence, the surface modified ways to enhance theperformance of pentacene OTFT are investigated by using different surface modifiedlayers. The main contents include:(1) Compared with the different surface modified gate dielectric, the cross linkedCPS is the best surface modified gate dielectric for the p-channel pentacene. Pentacenethin-film transistors fabricated on CPS modified dielectric layers exhibited chargecarrier mobility as high as1.11cm2V-1s-1. The bias stress stability for the CPS devicesshows that the drain current only decays1%after1530s and the mobility neverdecreases until13530s.(2) We have shown that the lateral correlation length of dielectric roughness stronglyaffects the charge transport properties of pentacene. Tow series of dielectric surfaces withdifferent lateral characteristics were prepared by a multilayer crosslinking polystyrene methodand a plasma etching method. For both methods, the increase of surface roughness causechanges in molecular and mesoscale structures and reduction in their charge carrier mobility.(3)256nm UV light was shined on the polystyrene surface modification layer toimprove bias stability of the organic transistors. Because crosslinking polystyrene maydecrease the end group of the polymer effect, the surface modified layers improve thebias stability of the devices on the air. And the charge carrier mobility and the biasstability of the devices on the air increased with the degree of cross-linked increased.(4) The field-effect mobility of the polystyrene/chlorosilane modified PVP and theHMDS modified PVP was58times and82times higher than the bare PVP layers. Theflexible device with HMDS modification had a maximum field-effect mobility of up to0.338cm2V1s1. The transfer curve showed an on/off current ratio exceeding104withthe off-current of about109A.(5) In order to improve procrss of pattern by using wet etching and dry etchingmethod, and we explore and improve the process on the production of organic thin filmtransistor to improve the electrical performance of the device. After completingpreparation of OTFT-OLED, we show the working principle of OTFT-OLED through the charging.