Large-area formation of self-aligned crystalline domains of organic semiconductors on transistor channels using CONNECT.

Steve Park, Gaurav Giri, Leo Shaw, Gregory Pitner, Jewook Ha, Ja Hoon Koo, Xiaodan Gu, Joonsuk Park, Tae Hoon Lee, Ji Hyun Nam, Yongtaek Hong, Zhenan Bao

Index: Proc. Natl. Acad. Sci. U. S. A. 112 , 5561-6, (2015)

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Abstract

The electronic properties of solution-processable small-molecule organic semiconductors (OSCs) have rapidly improved in recent years, rendering them highly promising for various low-cost large-area electronic applications. However, practical applications of organic electronics require patterned and precisely registered OSC films within the transistor channel region with uniform electrical properties over a large area, a task that remains a significant challenge. Here, we present a technique termed "controlled OSC nucleation and extension for circuits" (CONNECT), which uses differential surface energy and solution shearing to simultaneously generate patterned and precisely registered OSC thin films within the channel region and with aligned crystalline domains, resulting in low device-to-device variability. We have fabricated transistor density as high as 840 dpi, with a yield of 99%. We have successfully built various logic gates and a 2-bit half-adder circuit, demonstrating the practical applicability of our technique for large-scale circuit fabrication.