Application Of Self-assembled Monolayer In Organic Field-effect Transistor

The performance of organic field-effect transistor has improved greatly. But in terms of the overall development level of device performance, OFET can’t meet the commercial requirements. One of the factors is that carrier mobility of the devices is low, so It is necessary to increase the field-effect mobility of OFET. We mainly discuss a preparation optimization technique in this paper. In order to improve the mobility and on–off current ratio, we use various self-assembled monolayer to modify the surface of insulating layer. The details are as follows:The first part of this thesis introduces the field-effect transistor including working principle, characterization parameters, influencing factors. Besides, we describe the film-forming mechanism and technique of self-assembled monolayer. Finally, we introduce the application of self-assembled monolayer in organic field-effect transistor.In second part, we discuss the effect of PFTS, AYPA and ATS self-assembled monolayer on performance of grapheme transistor. We use SAMs of 1H, 1H, 2H, 2Hperfluorooctyltrimethoxysilane(PFTS),(3-aminopropyl)-trimethoxysilane(ATS) and(anthracen-9-ylmethyl) phosphonic acid(AYPA) to modify the surface of Si O2/Si substrates, then prepare graphene transistors. It is found that SAMs at the dielectric/graphene interface consistently improve the graphene device performance and reliability. The mobility of single layer graphene transistors on the SAMs engineered dielectric is currently up to 2904 cm2V-1s-1(Hole) and 2243 cm2V-1s-1(electron), considerably higher than the counterparts without the SAMs.The third part explores a strategy of using the phosphonic acid derivative(11-((12-(anthracen-2-yl)dodecyl)oxy)-11-oxoundecyl) phosphonic acid(ADO-PA) as self-assembled monolayer on Si O2/Si surface to induce the crystallization of rubrene in vacuum deposited thin film transistors, which showed a field-effect mobility as high as 0.18 cm2V-1s-1. It is found that ADO-phosphonic acid SAMs play a unique role in modulating the morphology of rubrene to form a crystalline film in the thin-film transistors.