Picture of athlete cycling

Open Access research with a real impact on health...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by Strathclyde researchers, including by researchers from the Physical Activity for Health Group based within the School of Psychological Sciences & Health. Research here seeks to better understand how and why physical activity improves health, gain a better understanding of the amount, intensity, and type of physical activity needed for health benefits, and evaluate the effect of interventions to promote physical activity.

Explore open research content by Physical Activity for Health...

Sub-micrometer patterning of amorphous- and β-phase in a crosslinkable poly(9,9-dioctylfluorene) : dual-wavelength lasing from a mixed-morphology device

Kuehne, A. J. C. and Kaiser, M. and Mackintosh, A. R. and Wallikewitz, B. H. and Hertel, D. and Pethrick, R. A. and Meerholz, K. (2011) Sub-micrometer patterning of amorphous- and β-phase in a crosslinkable poly(9,9-dioctylfluorene) : dual-wavelength lasing from a mixed-morphology device. Advanced Functional Materials, 21 (13). pp. 2564-2570. ISSN 1616-301X

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

The metastable β-phase morphology, inherent to most polyfluorene homo-polymers, is of interest due to its superior optical and electrical characteristics compared to its amorphous analogue. Here, a polyfluorene with vinyl-ether-functionalized aliphatic side-chains that allow crosslinking is reported. It is demonstrated that the previously induced conformational morphology is preserved in the resulting polyfluorene network, which enables subsequent wet thin-film processing. Electron-beam lithography provides a means for sub-(optical)-wavelength patterning of the crosslinkable polyfluorene films. As a specific demonstration, optically-pumped distributed-feedback (DFB) lasers made from surface-relief gratings in amorphous and β-phase polyfluorene are presented. By backfilling gratings of one morphology by the other, devices are demonstrated that exhibit lasing at two wavelengths with a threshold (<1 μJ cm−2) at least an order of magnitude lower compared with previous data.