Polymorph-Dependent Multi-Level Supramolecular Self-Assembly and Local Charge Transport of a Conjugated Polymer in Solution and Solid States

Junyang Deng, Wenhao Zheng, Yun Wang, Miao Cheng, Qingqing Jin, Yubin Ke, Zilong Zheng*, René A.J. Janssen, Ling Li, Ming Liu, Hai I. Wang*, Mengmeng Li*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The polymorphic behavior of conjugated polymers enables tunable optoelectronic properties, but their transport mechanism remains elusive due to the inherent complexity and uncontrollability of polymorphic self-assembly behaviors and electronic processes at various length scales, alongside the ambiguous relationship between solution and solid states. Herein, precise control of multi-level supramolecular self-assembly of a polymorphic conjugated polymer, N-PDPP4T-HD with two distinct semi-crystalline aggregated phases (β1 and β2) via solvent engineering is demonstrated. β1 forms 1D worm-like nanostructures in solution, whereas β2 generates 2D nanoscale lamellar configuration, confirmed by experimental observation and molecular dynamic simulation. Such solution-state features are inherited in the solid state (1D nanofibers for β1 and 2D granular-like structures for β2). X-ray characterizations reveal larger crystalline domains on the nanometer scale, reduced π-stacking distance on the Ångstrom scale, and diminished paracrystallinity disorder for solid-state β2. Going beyond conventional DC transistor characterizations, contact-free ultrafast terahertz spectroscopy to unveil AC short-range, intrinsic transport properties is employed. Longer charge carrier scattering time and thus intrinsic mobility of β2 result in threefold higher short-range photoconductivity than β1. This work establishes the “solution structure – solid structure – local transport” relation in polymorphic conjugated polymers and provides new opportunities for high-performance plastic electronic devices.

Original languageEnglish
JournalAdvanced Energy Materials
DOIs
Publication statusE-pub ahead of print - 5 Aug 2024

Keywords

  • charge transport
  • conjugate polymers
  • polymorphism
  • supramolecular assembly
  • terahertz spectroscopy

Fingerprint

Dive into the research topics of 'Polymorph-Dependent Multi-Level Supramolecular Self-Assembly and Local Charge Transport of a Conjugated Polymer in Solution and Solid States'. Together they form a unique fingerprint.

Cite this