Research On The Performance Of Thin Film Transistors Based On Vanadyl-phthalocyanine

Facing the rapid development of display area, organic thin film transistor will become a new generation of flexible display technology core. How to improve the field effect mobility and stability of device has become an important research subject.This paper studied the performance of vanadyl phthalocyanine organic thin film transistor with different modified substrates. The electrical characteristics of divices on various organosilane self-assembled monolayer(SAM) modified surfaces were researched, including the static contact angle of insulation layer surface, the AFM and XRD maps of vanadyl phthalocyanine thin film. And the air stability of VOPc OTFT had also been tested to analysis the factors what affact the stability of divices in the air.Through the research we found that, not only the surface hydrophobicity but also the length and type of organic capping group in organosilane SAMs affect the growth of VOPc films and OTFTs device performance. The interaction force between VOPc and insulation can be sffectively isolated by long alkyl chain group without halogen element, which can also reduce the concentration of the trap on the surface, conducive to the formation of large grain size, smooth continuous and a high degree of orientation, the high mobility of OTFTs device can be achieved. VOPc OTFT stored in O2 humidified by water exhibited the changes of electric characteristics, including positive-shifted threshold voltage and lower mobility. These conclusions could be supplied as experiment and theory foundations for the growth of organic semiconductor thin film, the fabrication of high-performance OTFTs and the packaging technology of devices.