Polarized blue photoluminescence of mesoscopically ordered electrospun non-conjugated polyacrylonitrile nanofibers
Conjugated polymers and oligomers that emit polarized light are used as active materials in various optoelectronic device applications, notably organic light-emitting diodes (OLEDs). Here, we demonstrate the fabrication of electrospun polarized light-emitting fibers from a non-conjugated polymer tha...
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Published in | Materials horizons Vol. 7; no. 6; pp. 165 - 1612 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
08.06.2020
|
Subjects | |
Online Access | Get full text |
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Summary: | Conjugated polymers and oligomers that emit polarized light are used as active materials in various optoelectronic device applications, notably organic light-emitting diodes (OLEDs). Here, we demonstrate the fabrication of electrospun polarized light-emitting fibers from a non-conjugated polymer that can be aligned by a simple heat-stretching process. Upon excitation at 340 nm, ribbons made from the nanofibers show polarized deep blue luminescence with an anisotropy of 0.37 and a quantum yield of about 31%. Furthermore, they exhibit room temperature green phosphorescence with a lifetime of about 200 ms as well as a delayed deep blue fluorescence resulting from triplet-triplet annihilation (non-coherent photon upconversion) (TTA). Wide and small angle X-ray scattering experiments show that the stretched electrospun fibers are highly aligned with nearly perfect uniaxial orientation within the fabricated ribbons. This results in a mechanically robust and flexible material, with a high specific tensile strength (534 ± 28) MPa cm
3
g
−1
and toughness (79 ± 7) J g
−1
. The combination of efficient polarized deep blue luminescence, room temperature phosphorescence, TTA, mechanical robustness and flexibility of these fibers opens up new avenues for applications of non-conjugated polymers.
Electrospun fibres from the non-conjugated polymer polyacrylonitrile are aligned by heat-stretching. These aligned fibers emit polarized blue fluorescence and green phosphorescence. |
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Bibliography: | 10.1039/d0mh00002g Electronic supplementary information (ESI) available. See DOI |
ISSN: | 2051-6347 2051-6355 |
DOI: | 10.1039/d0mh00002g |