Effect of Organic / Inorganic Gate Materials on the Organic Field-Effect Transistors Performance

Abstract

The choice of gate dielectric materials is fundamental for organic field effect transistors (OFET), integrated circuits, and several electronic applications. The operation of the OFET depends on two essential parameters: the insulation between the semiconductor layer and the gate electrode and the capacitance of the insulator. In this work, the electrical behavior of a pentacene-based OFET with a top contact / bottom gate was studied. Organic polyvinyl alcohol (PVA) and inorganic hafnium oxide (HfO₂) were chosen as gate dielectric materials to lower the operation voltage to achieve the next generation of electronic applications. In this study, the performance of the OFET was studied using monolayer and bilayer gate insulators. To model and analyze a device's electrical properties, MATLAB was used. Two main parameters were studied: switching ratio (I_on/I_off) and subthreshold swing (SS), as well as the effect of dielectric capacitance on the gate dielectric materials. The PVA/HfO₂ bilayer gate dielectric gave the best results in I_on/I_off ratio, SS and transconductance of 9.05´10^-7, -1.52, and -4.99 x10^-5A/V respectively, which is because the dielectric capacitance has increased.