MoOx interlayer to enhance performance of pentacene-TFTs with low-cost copper electrodes

We demonstrated that the electrical properties of pentacene-thin film transistors with low-cost Cu electrodes can be enhanced by inserting a thin MoOx interlayer layer between pentacene and Cu source/drain (S/D) electrodes. In comparison with the device having Cu-only electrodes, the performance of the device with MoOx/Cu electrodes was significantly improved. The saturation mobility increased from 0.13 to 0.61 cm2/V s, threshold voltage reduced from −14.5 to −7.3 V, on/off ratio shifted from 8.9 × 105 to 1.6 × 106 and threshold swing varied from 1.92 to 1.33 V/decade. The improvement was attributed to the reduction of contact resistance and the enhancement of hole-injection efficiency. The results suggest modification of Cu S/D electrodes is a simple and effective way to improve device performance and reduce the fabrication cost.