The study of the effect of flexible organic thin-film transistors with different polymer gate dielectrics

• Main Authors: Wei-Cheng Hong, 洪偉程
• Other Authors: Hsueh-Tao Chou
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/23219883279659170230

碩士 === 國立雲林科技大學 === 光學電子工程研究所 === 97 === Over the last decades, organic thin-film transistors (OTFTs) have attracted much attention for low-cost, flexible application and low-temperature fabrication. In this research, the material of pentacene is used as the active layer to fabricate OTFT devices on flexible polythyleneterephthalate (PET) substrate. The devices have four major layer: gate electrode, organic gate dielectric layer, organic active layer and source/drain electrode. We use evaporator and different masks to grow the thin films in this study. In addition to the organic gate dielectric layer, we adopted different polymer material poly (4-vinylphenol)(PVP), poly (methyl methacrylate) (PMMA), poly (vinyl alcohol)(PVA), poly (2-hydroxyethyl methacrylate) (PHEMA) as a gate dielectric by using a spin-coating method. By using atomic force microscopy (AFM), contact angles, and surface energy to analyze dielectric films and active films. Finally, we discussed the surface morphology of Pentacene grown on the different dielectric layers. In this research, we are successful to fabricate the low-cost and flexible organic thin-film transistors. The PVA 9%Wt. dielectric have a suitable surface energy of 44.19(mJ/m2) for Pentacene, so it have large grain size which lead to best electrical characteristics, including that the mobility is 3.82 cm2/Vs, the threshold voltage is -1.56V, and the On/Off current ratio is 3.38×103