摘要 |
The invention pertains to an (electro)luminescent polymer-acceptor system comprising a polymer with a plurality of chromophores doped with an acceptor for transferring excitation energy from the polymer to the acceptor wherein at least one wavelength of the polymer emission is a wavelength at which the acceptor absorbs energy, and for emitting energy as photons, characterized in that the dwell time of an exciton that is to be transferred from the polymer to the acceptor is longer than the time for transferring said exciton from the polymer to the acceptor, by satisfying the equation kET<pp><KET<pd>, wherein kET<pp >is the rate constant of the energy transfer at lambda between two chromophores of the polymer, kET<pd >is the rate constant of the energy transfer at lambda between the polymer and the acceptor. If the energy transfer processes in the polymer-acceptor system can be described by Förster theory the above equation can be rewritten as <math-cwu id="MATH-US-00001"> <NUMBER>1</NUMBER> <MATH> <MROW> <MSUP> <MOVER> <MI>R</MI> <MI>_</MI> </MOVER> <MI>pd</MI> </MSUP> <MO><</MO> <MROW> <MSUBSUP> <MI>R</MI> <MN>0</MN> <MI>pd</MI> </MSUBSUP> <MO>·</MO> <MSUP> <MROW> <MO>(</MO> <MFRAC> <MSUBSUP> <MI>tau</MI> <MI>ET</MI> <MI>pp</MI> </MSUBSUP> <MSUB> <MI>tau</MI> <MI>n</MI> </MSUB> </MFRAC> <MO>)</MO> </MROW> <MROW> <MN>1</MN> <MO>/</MO> <MN>6</MN> </MROW> </MSUP> </MROW> </MROW> </MATH> <mathematica-file id="MATHEMATICA-00001" file="US20040225106A1-20041111-M00001.NB"/> <image id="EMI-M00001" wi="216.027" he="19.93005" file="US20040225106A1-20041111-M00001.TIF" imf="TIFF" ti="MF"/> </MATH-CWU> {overscore (R<pd >is the mean distance between the polymer and the acceptor, R0<pd >is the Förster radius, and tauET<pp >and taun are the experimental lifetimes of a single chromophore and of the plurality of chromophores of the polymer, respectively.
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