Application Of Self-assembled Monolayers In Organic Thin Film Transistor

Although organic thin film transistors made great progress in its performance, butthere are still many problems. For organic thin film transistor mobility and off currentratio is low, this paper carried out a wide range of optimization and improvement,Mainly focused on the impact of the OTFT device performance after the modification ofmolecular self-assembly film organic semiconductor layer/insulating layer interface.The details are as follows:①This paper describes the OTFT research progress and hot research issue,discussed the application of molecular self-assembly techniques in the OTFT. Detaileddiscussion the basic structure, principle of OTFT and OTFT commonly used materials,including a substrate material, an electrode material, an insulating layer material and theorganic semiconductor materials.The p-type semiconductor, for example, elaboratedOTFT works and focuses on three main parameters of OTFT performance are discussed.②This paper focuses on molecular self-assembly film modified the active layer/insulating layer interface applications in organic thin-film transistors. Describes themolecular self-assembly technology works and preparation methods. Describes themolecular self-assembly of the transistor role played: reduce the surface roughness andthe energy of the insulating layer and increase the growth ordering of the organicsemiconductor material. Using a bottom-gate top-contact structure as the basic structureof the device, Small molecule organic material having a high mobility of6,13-diphenylpentacene (DPP) as the active layer material, n-Octadecylphosphonic acid (ODPA) andOTS as molecular self-assembly film material,6,13-diphenyl-pentacene (PQ) as organictemplate layer material, the surface of the silica formed by thermal oxidation (thicknessof about300nm) of heavily doped n-type silicon as the substrate material, SiO2as agate insulating layer, high work function of gold as source and drain electrode materials,Preparation OTFT devices.AFM test shows that molecular self-assembled monolayer was successfullyprepared. PQ layer and ODPA bilayer induce DPP to form a highly crystalline film arenecessary. When ODPA is replaced by OTS, DPP crystallinity of the film is deteriorated.Through the current-voltage characteristics calculated, by ODPA self-assemblingmolecules modification, PQ a template layer, DPP as the organic semiconductor layer, he mobility μ of the thin film transistor was prepared as8.3×10-3cm2/Vs, OFF currentratio Ion/Ioff reached2×104.③for the current n-type OTFT lower mobility problems, This paper will introducemolecular self-assembled monolayer graphene transistor, to explore its optimizationeffect of graphene devices: graphene layer is doped, adjusting the Fermi level of thegraphene layer to give the corresponding graphene semiconductor transistors;Lnhibition graphene device appears hysteresis during the test, so that carriertransportability of dielectric layer/organic layer in the graphene devices is more stable.And through the current-voltage characteristics were calculated for the mobility μ ofthe prepared thin film transistor. The test shows that the morphology of the graphenefilms growth on the modification self-assembled molecular layer better than thegraphene film grown directly on the surface of the insulating layer, crystallinity of thefilm was significantly improved.