Signatures of intracrystallite and intercrystallite limitations of charge transport in polythiophenes

Kiarash Vakhshouri, Brandon H. Smith, Edwin P. Chan, Chenchen Wang, Alberto Salleo, Cheng Wang, Alexander Hexemer, Enrique D. Gomez

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Charge carrier mobilities in conjugated semicrystalline polymers depend on morphological parameters such as crystallinity, crystal orientation, and connectivity between ordered regions. Despite recent progress in the development of conducting polymers, the complex interplay between the aforementioned parameters and their impact on charge transport is not fully understood. By varying the casting solvents and thermal annealing, we have systematically modulated the crystallization of poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly[2,5-bis(3-hexadecylthiophen-2-yl)thieno(3,2-b)thiophene] (PBTTT) thin films to examine the role of microstructure on charge mobilities. In particular, we achieve equal crystallinities through different processing routes to examine the role of structural parameters beyond the crystallinity on charge mobilities. As expected, a universal relationship does not exist between the crystallinity in either P3HT and PBTTT active layers and the charge mobility in devices. In P3HT films, higher boiling point solvents yield longer conjugation lengths, an indicator of stronger intracrystalline order, and therefore higher device mobilities. In contrast, the charge mobilities of PBTTT devices depend on the interconnectivity between crystallites and intercrystalline order in the active layer.

Original languageEnglish (US)
Pages (from-to)7359-7369
Number of pages11
JournalMacromolecules
Volume49
Issue number19
DOIs
StatePublished - Oct 11 2016

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Signatures of intracrystallite and intercrystallite limitations of charge transport in polythiophenes'. Together they form a unique fingerprint.

Cite this