Room-Temperature Fabrication of HfON Gate Insulator for Low-Voltage-Operating Pentacene-Based Organic Field-Effect Transistors

Low-voltage-operating pentacene-based organic field-effect transistors (OFETs) with different channel lengths have been fabricated by employing a room-temperature-processed HfON gate insulator. It was found that the on/off current ratio of the OFETs can be improved by decreasing the channel length. However, the hole mobility in the OFETs decreases with decreasing channel length owing to the effect of contact resistance. Interestingly, such OFETs with a short channel length (channel W/L = 500/50 µm) also show good electrical properties, such as a high hole mobility of 0.26 cm2 V-1 s-1, a low subthreshold swing of 0.13 V/decade, and a large on/off current ratio of 1×105 at an operating voltage of -2 V.