Engineering the Metal Gate Electrode for Controlling the Threshold Voltage of Organic Transistors

Abstract

For practical applications of organic field-effect transistors (OFETs), the control of threshold voltage (V-TH) is important as different circuits require different electrical characteristics. Here, we demonstrate two types of gate electrode structures to achieve this control, namely, via dual-metal gates and bilayer metal gates. The first approach uses different metallic materials, titanium, and platinum, while the second approach uses different thicknesses in a metal bilayer composed of aluminum and platinum. Our results show that the VTH is varied by more than 20% of the supply voltage without affecting the field-effect mobility values for both pentacene p-channel and C-60 n-channel OFETs. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4739511]