Open AccessMolecular weight dependent structure and charge transport in MAPLE‐deposited poly(3‐hexylthiophene) thin films
Author(s) -
Dong Ban Xuan,
Smith Mitchell,
Strzalka Joseph,
Li Huanghe,
McNeil Anne J.,
Stein Gila E.,
Green Peter F.
Publication year - 2018
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/polb.24588
Subject(s) - maple , crystallite , materials science , polymer , deposition (geology) , solvent , thin film , evaporation , polymer chemistry , chemistry , chemical engineering , crystallography , nanotechnology , composite material , organic chemistry , physics , botany , sediment , engineering , biology , thermodynamics , paleontology
In this work, poly(3‐hexylthiophene) (P3HT) films prepared using the matrix‐assisted pulsed laser evaporation (MAPLE) technique are shown to possess morphological structures that are dependent on molecular weight (MW). Specifically, the structures of low MW samples of MAPLE‐deposited film are composed of crystallites/aggregates embedded within highly disordered environments, whereas those of high MW samples are composed of aggregated domains connected by long polymer chains. Additionally, the crystallite size along the side‐chain (100) direction decreases, whereas the conjugation length increases with increasing molecular weight. This is qualitatively similar to the structure of spin‐cast films, though the MAPLE‐deposited films are more disordered. In‐plane carrier mobilities in the MAPLE‐deposited samples increase with MW, consistent with the notion that longer chains bridge adjacent aggregated domains thereby facilitating more effective charge transport. The carrier mobilities in the MAPLE‐deposited simples are consistently lower than those in the solvent‐cast samples for all molecular weights, consistent with the shorter conjugation length in samples prepared by this deposition technique. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56 , 652–662