Low-voltage pentacene transistor inverters using micro-contact printed nano-layer

We report on low-voltage inverters with two pentacene-based thin-film transistors (TFTs), one of which has been fabricated on a dielectric surface selected by micro-contact printing (mu CP). When a self-assembled monolayer (SAM) of 7-octenyltrichlorosilane (7-OTS) was printed on AlO(x) dielectric oxide, the TFT with the mu CP-SAM displayed a large threshold voltage (V(th)) shift (3 V shift under -5 V operation), increased device current, and clearly changed pentacene surface morphology as compared to those of the other TFT without mu CP-SAM. Those results are attributed to the 7-OTS-modified pentacene/AlO(x) interface. Our inverter, composed of two TFTs with and without mu CP-SAM, shows a high gain of similar to 50 at a supply voltage (V(DD)) of -20 V.S. Im and M. M. Sung acknowledge the financial support from KOSEF (NRL program, No. 2009-8-0430 & 2009-00-92807), BK21 Project, and MKE (21st century Frontier R&D Program: No. F0004022-2009). K. H. Lee acknowledges the scholarship support from the KOSFFL