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Title: Enhancing Molecular Alignment and Charge Transport of Solution-Sheared Semiconducting Polymer Films by the Electrical-Blade Effect

Controlling polymer chain alignment through processing is a means of tuning the charge transport of solution-based conjugated polymers. In this work, a processing strategy is proposed in which an external electric field (E-field) is applied to the coating blade (E-blade) to align polymer chain during solution-shearing, a meniscus-guided coating technique. A theoretical model based on dielectrophoresis quantitatively describes and predicts the alignment process and is used to guide the selection of the optimal conditions of the applied E-field. Using these conditions, more than two-fold increase in chain alignment is observed for E-bladed thin films of a diketopyrrolopyrrole (DPP) semiconducting polymer without affecting other morphological aspects such as film thickness, film coverage or fiber-like aggregation. Organic field effect transistors based on the E-bladed DPP polymer are fabricated at ambient conditions and over areas of a few cm2. They display a 3-fold improvement in their mobilities and a strong enhancement in charge transport anisotropy compared to films prepared without E-field. These results reveal a synergistic alignment effect from both the solution-shearing process and the applied E-field, and introduce a novel and general approach to control the morphology and the electrical properties of solutioncoated conjugated polymer thin films.
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  1. Stanford Univ., CA (United States)
  2. Stanford Univ., CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; SC0016523; P2ELP2_155355; ECCS-1542152; 106-2917-I-564-023
Accepted Manuscript
Journal Name:
Advanced Electronic Materials
Additional Journal Information:
Journal Volume: 4; Journal Issue: 7; Journal ID: ISSN 2199-160X
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1438076