Series
School of Chemical and Biomolecular Engineering Seminar Series

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Event Series
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Associated Organization(s)

Publication Search Results

Now showing 1 - 2 of 2
  • Item
    Tunable Crystallinity in Poly(3-Hexylthiophene) and its Impact on Charge Transport
    (Georgia Institute of Technology, 2011-10-05) Aiyar, Avishek R.
    The properties of poly(alkylthiophenes) in solution are found to have a profound impact on the self-assembly process and thus the microstructural and electrical properties of the resultant thin films. Ordered supramolecular precursors can be formed in regioregular poly(3- hexylthiophene) (P3HT) solutions through the application of low intensity ultrasound. These precursors survive the casting process, resulting in a dramatic increase in the degree of crystallinity of the thin films obtained by spin coating. The crystallinity of the films is tunable, with a continuous evolution of mesoscale structures observed as a function of ultrasonic irradiation time. The photophysical properties of P3HT in solution as well in the solid state suggest that the application of ultrasound leads to a π stacking induced molecular aggregation resulting in field effect mobilities as high as 0.03 cm2V-1s-1. A multiphase morphology, comprising short quasi-ordered and larger, ordered nanofibrils embedded in a disordered amorphous phase is formed as a result of irradiation for at least 1 minute. We identify two distinct regions of charge transport characterized by an initial sharp increase in the field effect mobility by two orders of magnitude due to an increase in crystallinity up to the percolation limit, followed by a gradual saturation where the mobility becomes independent of the thin film microstructure.
  • Item
    Fourth Year Colloquium, October 22, 2008 [Program]
    (Georgia Institute of Technology, 2008-10-22)
    Complete colloquium program, including abstacts and location information for the 2008 School of Chemical and Biomolecular Engineering Fourth Year Colloquium.