Performance enhancement of solution-processed organic thin-film transistors incorporating an improved Corbino structure.

The solution-processed organic thin-film transistors (OTFTs) with a minimal device footprint and improved performance are desirable for flexible electronics and other circuit applications. It is demonstrated that the enhanced performance can be achieved for solution-processed OTFTs by adopting an improved Corbino structure. The bottom-gate bottom-contact OTFTs of W/L ratio of 500 are fabricated using the standard poly-3-hexylthiophene (P3HT) as a semiconductor with an improved interdigitated pseudo-Corbino (IPC) structure. The exhibited IPC structure is a combination of interdigitated structure in the enclosed-Corbino design to achieve infinite output resistance, suppressed parasitic leakage current, and high ON current by accommodating a high W/L ratio in a minimal device footprint. For the fabricated solution-processed OTFTs, infinite output resistance with an OFF-current of the order of 1 0 − 12 A and an ON/OFF ratio of drain current of the order of 1 0 7 is achieved. Incorporating an enhanced hexamethyldisilazane treatment of the Si O 2 gate dielectric improves the ON/OFF ratio to a record value of 1 0 8 and the mobility of the order of 1 0 − 2 cm 2 / Vs for P3HT. Implementation of IPC-TFT structure for intentionally chosen moderate-mobility, solution-processed P3HT semiconductor results in a consistent low OFF-current, high ON/OFF ratio, and infinite output resistance with excellent device-to-device uniformity. [ABSTRACT FROM AUTHOR]