POS4-0776
Molecular Doping-Induced Spontaneous Defect Healing and Enhanced Structural Order in Uniaxially Aligned P3HT Films
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Seyoun Hwang (Hanyang University)
Co-Author(s)
Abstract
Charge-transfer doping has been widely employed to enhance the electrical properties of semiconducting polymers; however, the specific effects of the doping process on polymer microstructures remain poorly understood. In this study, we fabricated highly aligned poly(3-hexylthiophene) (P3HTEFT) thin films via the Eutectic Friction Transfer (EFT) process, exhibiting superior molecular alignment and surface flatness compared with conventional spin-coated films (P3HTSC), and report a spontaneous defect-healing phenomenon induced by molecular p-doping. Upon incorporation of the p-dopant F4TCNQ, torsional defects and transient amorphous phases within the oriented P3HT films were efficiently transformed into highly aligned crystalline domains with enhanced uniaxial alignment. Comprehensive characterization using polarized spectroscopy, FT-IR spectroscopy, Raman spectroscopy, and GIWAXS revealed that this selective molecular rearrangement induces pronounced structural anisotropy and significantly improves long-range structural order and charge-carrier mobility. In contrast, spin-coated P3HT films retained their amorphous morphology, exhibiting little structural reorganization upon doping. By elucidating the distinct phase-transition pathways of transient amorphous and settled amorphous phases, this study demonstrates that the combination of macroscopic chain alignment and molecular doping provides an effective strategy for precisely controlling the structure of polymer thin films for next-generation high-performance organic electronic devices.
