SL 19


K. Cho

Dept. of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea (

Control over surface induced self-assembly of electronically active pi-conjugated molecules provides great opportunities to fine-tune and optimize their electrical properties for applications in organic electronics. The design of substrates with controllable surface properties can be effectively achieved employing functionalized self-assembled monolayers (SAMs), which have become one of the most popular techniques to create well-defined functional nanostructures. By self-assembly of pi-conjugated nanostructures with strongly pi-pi interacting building blocks via surface chemistry, even the highest mobilities and possibly, a truly delocalized transport regime, may be attained. In this study, with the aim of enhancing the electrical performances by promoting surface induced two-dimensional self-assembly in representative pi-conjugated molecules such as poly (3-hexylthiophene) and pentacene, we have controlled the intermolecular interaction at the interface between pi-conjugated molecules and substrate by using SAMs functionalized with various groups. We will discuss the dependency of pi-conjugated molecules on the specific properties of the substrate surface and the effect of surface induced self-assembly on electrical performances in organic transistors.

1) D. H. Kim, Y. D. Park, Y. Jang, H. Yang, Y. H. Kim, D. G. Moon, J. I. Han, S. Park, T. Chang, C. Chang, M. Joo, C. Y. Ryu, K. Cho, Adv. Funct. Mater., 15, 77 (2005).

2) D. H. Kim, Y. Jang, Y. D. Park, K. Cho, Langmuir, 21, 3203 (2005).

3) D. H. Kim, Y. D. Park, Y. Jang, K. Cho, Macromol. Rapid Comm., 26, 834 (2005).

4) H. Yang, T. J. Shin, M. -M. Ling, K. Cho, C. Y. Ryu, Z. Bao, J. Am. Chem. Soc., 127, 11542 (2005)

5) D. H. Kim, Y.Jang, Y.D.Park, K.Cho, Macromolecules 39, 5843 (2006)

6) D. H. Kim, Y. Jang, Y. D. Park. K. Cho, J. Phys. Chem. B 110, 15763 (2006)

7) H. S. Lee, D. H. Kim, J. H. Cho, Y. D. Park, Y. Jang, M. K. Hwang, J. A. Lim, J. S. Kim, K. Cho, Adv. Funct. Mater., 16, 1854 (2006).

8) D. H. Kim, J. T. Han, Y. D. Park, Y. Jang, J. H. Cho, K. Cho, Adv. Mater., 18, 719 (2006).

9) D. H. Kim, D. Y. Lee, H. S. Lee, W. H. Lee, Y. H. Kim, J. I. Han, K. Cho, Adv. Mater., 19, 678 (2007)

10) W. H. Lee, D. H. Kim, Y. Jang, J. H. Cho, Y. H. Kim, J. I. Han, K. Cho, Appl. Phys. Lett., 90, 132106 (2007)