Organic field-effect transistors (OFETs) have the advantages of low-cost, large-area processing and could be utilized in a variety of emerging applications. However, the generally large contact resistance (Rc) limits the integration and miniaturization of OFETs. The Rc is difficult to reduce due to an incompatibility between obtaining strong orbit coupling and the barrier height reduction. In this study, we developed an oxygen-induced barrier lowering strategy by introducing oxygen (O2) into the nanointerface between the electrodes and organic semiconductors layer and achieved an ultralow channel width-normalized Rc (Rc·W) of 89.8 Ω·cm and a high mobility of 11.32 cm2 V-1 s-1. This work demonstrates that O2 adsorbed at the nanointerface of metal-semiconductor contact can significantly reduce the Rc from both experiments and theoretical simulations and provides guidance for the construction of high-performance OFETs, which is conducive to the integration and miniaturization of OFETs.
Keywords: OFETs; contact barrier; contact resistance; defects; oxygen treatment.