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.

Graphical abstractFigure optionsDownload full-size imageDownload 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.