Tunable contact resistance in double-gate organic field-effect transistors

A study of the contact resistance (R-sd) in pentacene-based double-gate transistors is presented. In top-contact transistors, as the negative bias of the additional top-gate bias is increased, R-sd decreases by over five orders of magnitude for small bottom-gate voltages. In bottom-contact transistors, R-sd is reduced by about ten times for all bias values, implying improved charge transport in all operating regimes. The different tunability of R-sd in top/ bottom-contact transistors is attributed to different charge injection modulation by thecoplanar/staggered top gate. Therefore, double-gate architecture offers a novel and effective approach to limit R-sd and its relevant impacts on organic transistor. (C) 2012 Elsevier B. V. All rights reserved.