Fluorene-arylamine copolymers: separable control of hole transport and light emission through composition and conformation
Author(s)
Lambeva, Nikol T
Limbu, Saurav
Kim, Ji-Seon
Bradley, Donal DC
Type
Journal Article
Abstract
Suitable model polymer systems enable systematic studies that can progress understanding of structure–property relationships in these chemically diverse materials. To this end, the hole mobility of four fluorene-arylamine copolymers containing varying ratios of 9,9-dioctylfluorene and butyl-substituted phenylenediamine has been studied. The copolymers with longer sequences of fluorene units can adopt the chain-extended β-phase conformation, and its effect on transport is also investigated. The room temperature hole mobility of the fluorene homopolymer, poly(9,9-dioctylfluorene), is drastically reduced by copolymerization of 5% arylamine units due to trapping at the arylamine sites. With increasing arylamine percentage, the mobility rises due to the commencement of direct arylamine-to-arylamine transport. Air photoemission spectroscopy measurements reveal two separate contributions to the photoemission signal whose intensities vary with composition, rather than a single energy level that shifts continuously from fluorene to arylamine, as has sometimes been assumed in transport models. This work demonstrates both that mobility can be controlled over a large range in these copolymers and that the role of fluorene β-phase formation is secondary here to chemical composition. Conversely, the light emission properties are strongly affected by conformation. The transport and emission characteristics are thereby separable, consistent with the observed multifunctional nature of state-of-the-art complex copolymers.
Date Issued
2025-05-01
Date Acceptance
2025-03-06
Citation
Journal of Polymer Science, 2025, 63 (9), pp.2113-2121
ISSN
2642-4150
Publisher
Wiley
Start Page
2113
End Page
2121
Journal / Book Title
Journal of Polymer Science
Volume
63
Issue
9
Copyright Statement
© 2025 The Author(s). Journal of Polymer Science published by Wiley Periodicals LLC. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Subjects
charge trapping
CHARGE-LIMITED CURRENTS
copolymers
EFFICIENCY
EMITTING-DIODES
HIGH-MOBILITY HOLE
hole transport
KELVIN PROBE
mobility
PHASE
Physical Sciences
polyfluorenes
Polymer Science
POLYMERS
PRESSURE PHOTOEMISSION-SPECTROSCOPY
PROGRESS
Science & Technology
TRANSIENT
Publication Status
Published
Date Publish Online
2025-03-28