Staff profile
Publication details for Professor Andy Monkman
Burrows, HD, Miguel, MD, Monkman, AP, Hamblett, I & Navaratnam, S (2001). Transient absorption spectra of triplet states and charge carriers of conjugated polymers. Journal Of Molecular Structure 563: 41-50.- Publication type: Journal papers: academic
- ISSN/ISBN: 0022-2860
- Keywords: conjugated polymers; pulse radiolysis; triplet excited states; charge carriersLIGHT-EMITTING-DIODES; PULSE-RADIOLYSIS; ENERGY-TRANSFER; OLIGOMERS; OLIGO(PHENYLENEVINYLENE)S; POLY(P-PHENYLENEVINYLENE); ELECTROLUMINESCENCE; PHOSPHORESCENCE; POLYACETYLENE; R
Author(s) from Durham
Abstract
The use of pulse radiolysis to study transient species in conjugated
polymers in solutions is discussed, with particular reference to
poly(2-methoxy-5-(2'-ethylhexoxy)-p-phenylenevinylene (MEH-PPV). The
excited tripler state is specifically generated by energy transfer on
radiolysis of benzene solutions in the presence of suitable
sensitisers, and its spectrum is reported. The presence of vibronic
structure suggests a localised tripler state. By varying the energy of
the sensitiser, it is possible to determine the energy of the lowest
triplet state. Results are also presented for the triplet-triplet
absorptions and energies of five other common pi -conjugated polymers.
The MEH-PPV tripler absorption, produced on radiolysis, does not
increase linearly with either polymer concentration or radiation dose.
This is suggested to be due to the presence of multiple tripler
excitations on the isolated polymer chains. Intrachain triplet-triplet
annihilation is observed, and is seen to lead to delayed fluorescence.
Spectra are also reported for the positive and negative charge carriers
of MEH-PPV and the other polymers specifically produced by pulse
radiolysis of the polymers in chloroform or tetrahydrofuran solutions.
(C) 2001 Elsevier Science B.V. All rights reserved.