低栅极电压控制下带有phenyltrimethoxysilane单分子自组装层的有机薄膜晶体管场效应特性研究

制作了底栅极顶接触有机薄膜晶体管器件，60 nm的pentacene被用作有源层，120 nm热生长的SiO₂作为栅极绝缘层.通过采用不同自组装修饰材料对器件的有源层与栅极绝缘层之间的界面进行修饰，如octadecyltrichlorosilane （OTS），phenyltrimethoxysilane （PhTMS），来比较界面修饰层对器件性能的影响.同时对带有PhTMS修饰层的OTFTs器件低栅极电压调制下的场效应行为及其载流子的传输机理进行研究.结果得到，当|V 关键词： 有机薄膜晶体管 自组装单分子层 场效应迁移率 低栅极调制电压

Study of the characteristics of organic thin film transistors with phenyltrimethoxysilane buffer under low gate modulation voltage

We have fabricated the top-contact organic thin film transistors （OTFTs） with, a 60 nm thick pentacene films as active layer and a 120 nm thermal growth SiO2 as gate insulator. Through using different self-assembled monolayers ,such as octadecyltrichlorosilane （OTS） and phenyltrimethoxysilane （PhTMS）, as a buffer between the organic semiconductor active layer and gate insulator, we studied the effect of different buffers on the performance of OTFTs device. At the same time, we also investigated the field-effect behavior and carrier transport mechanism of OTFTs device with PhTMS buffer under low gate modulation voltage. When |V_GS|<0.1 V we found that under such low gate modulation voltage the carriers can no more accumulate at the interface between the organic semiconductor active layer and gate insulator, resulting in the output current I_DS of OTFTs device keeping balance. But the OTFT device still has good output characteristics, with the field-effect mobility （μ_EF） of 3.22×10^-3 cm²/Vs, （on/off） current ratio of 1.43×10², and threshold voltage （V_TH） of -0.66 V.