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

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

Figure optionsDownload as PowerPoint slideHighlights
► Contact resistance (Rsd) can be tuned in the double-gate OFETs.
► In TC transistors, Rsd can be reduced by the negatively increased top-gate bias.
► In BC transistors, Rsd can be effectively reduced over all biases.
► Higher tunability in BC devices is attributed to staggered configuration.
► Double-gate architecture could be a novel and effective manner to reduce Rsd.