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There is a critical need to develop a method to pattern semiconducting polymers for device applications on the sub-micrometer scale. Dopant induced solubility control (DISC) patterning is a recently published method for patterning semiconductor polymers that has demonstrated sub-micron resolution. DISC relies on the sequential addition of molecular dopants (here 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ)) to the conjugated polymer. In doped areas, the conjugated polymer is protected from dissolution while in undoped areas, the polymer dissolves into solution. Here we examine factors that affect the resolution of the developed pattern. Two factors are determined to be critical to pattern resolution, the initial crystallinity of the polymer, here poly(3-hexylthiophene) (P3HT), and the quality of the development solvent. We find that dopants diffuse more readily in highly crystalline films than in amorphous films of P3HT and that dopant diffusion reduces the fidelity of the resulting pattern. We also find that the choice of development solvent affects both the fidelity of the pattern and dopant distribution within the patterned polymer domains. Finally, we show that a dopant that diffuses more slowly than F4TCNQ in the P3HT film can be used to pattern the film with higher fidelity. These results together provide a road map for optimizing additive DISC patterning for any polymer/dopant pair.
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This content will become publicly available on December 1, 2025
Preparation of poly(3‐hexylthiophene) conjugated polymer brush films from amine‐terminated surfaces
Abstract Conjugated polymer brush (CPB) films are more robust and exhibit more vertically aligned polymer chains than their spun‐cast analogs. We prepare CPB films of poly(3‐hexylthiophene) (P3HT) by coupling an amine‐terminated surface (ATS) formed from (3‐aminopropyl)triethoxysilane (APTES) on Si/SiO2to 4‐bromobenzoic acid using standard, inexpensive peptide coupling reagents. The resulting terminal bromobenzene is reacted with Pd(PtBu3)2and immersed in the monomer solution. X‐ray photoelectron spectroscopy, spectroscopic ellipsometry and static water contact angle measurements confirm the surface chemistry at each stage of P3HT CPB preparation. Atomic force microscopy(AFM) and UV–vis spectrophotometry indicate that the CPB films prepared by this method exhibit similar morphology and optical properties to those produced from other methods of poly(3‐alkylthiophene) CPB film preparation. Variations of the standard approach, such as using a pre‐synthesized silane counterpart or with (11‐aminoundecyl)triethoxysilane, show comparable film morphologies by AFM. This method is used to produce the first CPB film of poly(3‐dodecylthiophene), showing its utility for exploring CPB films of more sterically demanding polymers. Peptide coupling is used to prepare an analogous functionalized thiol for initiating P3HT CPB film growth from Au surfaces, and microcontact printing with this thiol allows preparation of the first patterned CPB film of P3HT.
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- Award ID(s):
- 2320222
- PAR ID:
- 10631741
- Publisher / Repository:
- Wiley Periodicals LLC
- Date Published:
- Journal Name:
- Journal of Polymer Science
- Volume:
- 62
- Issue:
- 23
- ISSN:
- 2642-4150
- Page Range / eLocation ID:
- 5384 to 5397
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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