Abstract
New dithienothiophene-containing conjugated polymers, such as poly(2,6-bis(2-thiophenyl-3-dodecylthiophene-2-yl)dithieno[3,2-b;2′, 3′-d]thiophene, 4 and poly(2,6-bis (2-thiophenyl-4-dodecylthiophene-2-yl) dithieno[3,2-b;2′,3′-d]thiophene, 8 have been successfully synthesized via Stille coupling reactions using dodecyl-substituted thiophene-based monomers, bistributyltin dithienothiophene, and bistributyltin bithiophene; these polymers have been fully characterized. The main difference between the two polymers is the substitution position of the dodecyl side chains in the repeating group. Grazing-incidence X-ray diffraction (GI-XRD) gave clear evidence of edge-on orientation of polycrystallites to the substrate. The semiconducting properties of the two polymers have been evaluated in organic thin film transistors (OTFTs). The two conjugated polymers 4 and 8 exhibit fairly high hole carrier mobilities as high as μave = 0.05 cm 2/Vs (ION/OFF = 3.42 × 104) and μave = 0.01 cm2/Vs, (ION/OFF = 1.3 × 105), respectively, after thermal annealing process. The solvent annealed films underwent reorganization of the molecules to induce higher crystallinity. Well-defined atomic force microscopy (AFM) topography supported a significant improvement in TFT device performance. The hole carrier mobilities of the solvent annealed films are comparable to those obtained for a thermally annealed sample, and were one-order higher than those obtained with a pristine sample.
Original language | English |
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Pages (from-to) | 55-64 |
Number of pages | 10 |
Journal | Journal of Polymer Science, Part A: Polymer Chemistry |
Volume | 49 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2011 Jan 1 |
Keywords
- annealing
- charge transport
- conjugated polymer
- dithienothiophene
- mobility
- organic thin film transistor
- semiconductor
- synthesis
- thin films
ASJC Scopus subject areas
- Polymers and Plastics
- Organic Chemistry
- Materials Chemistry