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Internal Field Screening in Polymer Light‐Emitting Diodes
Author(s) -
Brewer P. J.,
Lane P. A.,
deMello A. J.,
Bradley D. D. C.,
deMello J. C.
Publication year - 2004
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200305126
Subject(s) - polyfluorene , materials science , anode , optoelectronics , diode , oled , electric field , polymer , spectroscopy , organic semiconductor , light emitting diode , semiconductor , pedot:pss , sulfonate , conductive polymer , electroluminescence , electron , copolymer , nanotechnology , electrode , composite material , layer (electronics) , chemistry , physics , quantum mechanics , sodium , metallurgy
We use electromodulation spectroscopy and modeling studies to probe the electric‐field distribution in polyfluorene‐based polymer light‐emitting diodes containing poly(3,4‐ethylenedioxythiophene) poly(styrene sulfonate). The bulk internal field is shown to be zero under ordinary operating conditions, with trapped electrons close to the anode fully screening the bulk semiconductor from the external field. The effect has far‐reaching implications for the understanding and optimization of organic devices.