Correlating structure with fluorescence emission in phase-separated conjugated-polymer blends

Chappell, J.; Lidzey, D.G.; Jukes, P.C.; Higgins, A.M.; Thompson, R.L.; O'Connor, S.; Grizzi, I.; Fletcher, R.; O'Brien, J.; Geoghegan, M.; Jones, R.A.L.

Abstract

Blends of conjugated polymers are frequently used as the active semiconducting layer in light-emitting diodes and photovoltaic devices. Here we report the use of scanning near-field optical microscopy, scanning force microscopy and nuclear-reaction analysis to study the structure of a thin film of a phase-separated blend of two conjugated polymers prepared by spin-casting. We show that in addition to the well-known micrometre-scale phase-separated morphology of the blend,, one of the polymers preferentially wets the surface and forms a 10-nm-thick, partially crystallized wetting layer. Using near-field microscopy we identify unexpected changes in the fluorescence emission from the blend that occurs in a 300-nm-wide band located at the interface between the different phase-separated domains. Our measurements provide an insight into the complex structure of phase-separated conjugated-polymer thin films. Characterizing and controlling the properties of the interfaces in such films will be critical in the further development of efficient optoelectronic devices.

Citation

Chappell, J., Lidzey, D., Jukes, P., Higgins, A., Thompson, R., O'Connor, S., …Jones, R. (2003). Correlating structure with fluorescence emission in phase-separated conjugated-polymer blends. Nature Materials, 2(9), 616-621

• Journal Article Type: Article
• Publication Date: 2003-09
• Journal: Nature Materials
• Print ISSN: 1476-1122
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 2
• Issue: 9
• Pages: 616-621
• Public URL: https://durham-repository.worktribe.com/output/1571029