Inkjet-Printed Organic Electrodes for Bottom-Contact Organic Field-Effect Transistors

A graphite thin film was investigated as the drain and source electrodes for bottom-contact organic field-effect transistors (BC OFETs). Highly conducting electrodes (10 2 S cm −1 ) at room temperature were obtained from pyrolyzed poly(l,3,4-oxadiazole) (PPOD) thin films that were prepatterned with a low-cost inkjet printing method. Compared to the devices with traditional Au electrodes, the BC OFETs showed rather high performances when using these source/drain electrodes without any further modification. Being based on a graphite-like material these electrodes possess excellent compatibility and proper energy matching with both p- and n-type organic semiconductors, which results in an improved electrode/organic-layer contact and homogeneous morphology of the organic semiconductors in the conducting channel, and finally a significant reduction of the contact resistance and enhancement of the charge-carrier mobility of the devices is displayed. This work demonstrates that with the advantages of low-cost, high-performance, and printability, PPOD could serve as an excellent electrode material for BC OFETs.