[15a-423-1~9] CS.4 7. Code-sharing Session: Beam Technology and Nanofabrication

[15a-423-9] Direct fabrication and characteristics of soluble conductive polymer nanowires
by squeegee process

〇(M2)shiho kuroyanagi¹, takamichi miyazaki², shinae heo³, kazunori sugiyasu³, masaru nakagawa¹, yutaka wakayama³ (1.IMRAM, Tohoku Univ., 2.Eng. Tohoku Univ., 3.NIMS)

Keywords:UV nanoimprint lithography, poly(3-hexylthiophene), conductive atomic force microscope

Nanowires of soluble conductive polymers have been receiving increasing attention due to their unique properties different from their bulks. In particular, some conductive polymer nanowires show higher conductivity than those of bulks due to their morphological and orientational effects. Poly(3-hexylthiophene) (P3HT) is one of typical soluble conductive polymers and has been widely studied for electronic device applications. Up to date, P3HT nanowires are prepared by spincoating of P3HT solutions with a halogen-containing solvent onto nanotrenches, followed by reactive ion etching (RIE). However, no one knows whether the presence of residual halogen species and the chemical damage of nanowires induced by RIE influence on conductivity of the P3HT nanowires. In this study, we investigated how to prepare P3HT nanowires without any of halogen-containing solvents and RIE processes and demonstrated a squeegee process to fabricate P3HT nanowires. A P3HT film on nanotrenches with concave pattern widths of 60 - 100 nm was prepared by spincoating a toluene solution containing P3HT. The outermost film surface was wiped repeatedly certain times with a silicone squeegee swelled with toluene. The nanotrenches stuffed with P3HT was observed by a field-emission scanning electric microscope (FE-SEM) and a conductive atomic force microscope (c-AFM). Cross-sectional FE-SEM images suggested that concave patterns in nanotrenches were successfully filled with P3HT. A 2-dimensional current map measured with a constant voltage revealed that conductive regions were observed in accordance with concave line patterns of nanotrenches. This confirmed that P3HT nanowires could be simply prepared by the squeegee process without halogen-containing solvents and RIE process.