Vertical Conducting Nanodomains Self-Assembled from Poly(3-hexylthiophene)-Based Diblock Copolymer Thin Films

Journal Article · Sat Dec 31 04:00:00 EST 2011 · Journal of Physical Chemistry C

DOI:https://doi.org/10.1021/jp109208n· OSTI ID:1042239

Lee, Y; Kim, S; Yang, H; Jang, M; Hwang, S; Lee, H; Baek, K

We have synthesized {pi}-conjugated poly(3-hexyl thiophene)-block-poly(methyl methacrylate) (P3HT-b-PMMA) with a P3HT molecular weight of 11 kDa and a PMMA volume fraction of 0.53, which potentially has several organic electronic applications. Its phase-separation behavior was investigated for various thicknesses cast from organic solvents. When cast onto 300 nm thick SiO{sub 2} dielectrics from toluene, in which the P3HT segments have limited solubility, the P3HT-b-PMMA films consist of nanofibrillar self-assemblies of laterally {pi}-stacked P3HT chains. In contrast, the P3HT segments were found to be highly mobile in chlorobenzene, generating a typical phase-separation morphology consisting of vertically conducting P3HT nanodomains on these dielectrics. As the thickness of the cast films increased, however, the topmost surface becomes covered with {pi}-conjugated nanofibrils that are laterally oriented with respect to the surface. Due to the anisotropic domain orientations of P3HT, top-gate organic field-effect transistors (OFETs) containing the P3HT-b-PMMA films exhibited enhanced electrical performance compared to bottom-gate OFETs.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1042239
• Report Number(s): BNL--97917-2012-JA
• Journal Information: Journal of Physical Chemistry C, Journal Name: Journal of Physical Chemistry C Journal Issue: 10 Vol. 115; ISSN 1932-7447
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHAINS
COPOLYMERS
DIELECTRIC MATERIALS
MOLECULAR WEIGHT
MORPHOLOGY
ORGANIC SOLVENTS
PERFORMANCE
SOLUBILITY
THICKNESS
THIN FILMS
TOLUENE
TRANSISTORS