The Research Of Hybrid Insulating Layer In Organic Thin Film Transistors

Organic thin film transistor is widely used in display, sensor, integrated circuits and other fields because it has simple preparation process, low cost, good flexibility and other advantages. The surface properties of insulating layer can influence the crystalline quality of semiconductor layer which grows on the insulating layer, so it ’s crucial to the performance of the whole device. This paper synthesized a kind of organic/inorganic hybrid insulation film, aiming to combinate the advantage s of the high dielectric constants of inorganic material and the low surface roughness of organic material to optimize the performance of the device. The specific contents are as follows:Firstly, this paper introduces the application fields, research status and existing problems of the OTFT, and detailedly describes its working principle and basic structure. On this basis, this paper introduces some performance indexes of the OTFT and how to select the materials. The preparation technology and preparation process of the OTFT are analyzed, the measuring instruments used in this paper and their working principles are explained.Secondly, the effect of organic insulating layer of copper phthalocyanine OTFT is deeply studied. Si O2 and PVA are modified by PMMA, the output current and mobility of double insulating layer device are higher than the single insulating layer device. Then this paper researches the effect of new polymer P(MMA-GMA) as insulating layer, after thinning the thickness of the insulating layer, the performance of the device is improved significantly.Thirdly, we prepare OTFTs based on PVA/P(MMA-GMA) and P(MMA-GMA), finding the threshold voltage of double insulating layer device is improved from-5V to-3V, and its mobility is increased from 5.24×10-3cm2/Vs to 1.15×10-2cm2/Vs. This paper analyzes the reason of the improved device performance.Finally, this paper studies the copper phthalocyanine OTFT based on the Al2O3/P(MMA-GMA) hybrid insulating layer, determines the technological parameters of Al2O3 thin film, which is prepared by magnetron sputtering method, and analyzes film growth with atomic force microscope and X ray diffraction.