In the field of electroluminescent organic materials, conjugated polymers h
ave attracted much attention over recent pears owing to their versatile syn
thesis, their relative ease of processing and the possibility of establishi
ng predictive structure-function relationships between chemical structures
and optical properties. This review article highlights the advances made in
the synthesis of conjugated polymers for use in light-emitting devices (LE
Ds) covering the last two years. Research efforts were largely directed tow
ards the improvement of the synthesis of monomers and polymers involving cl
assical polymer structures such as poly(p-phenylene vinylene)s (PPVs), poly
(p-phenylene)s (PPPs), poly(2,7-fluorene)s (PFs), or poly(2,5-thienylene)s
(PTs). Control of the color of emission by modulation of the effective conj
ugation length, improving balanced charge injection and transport propertie
s by introduction of electron-donating or -withdrawing moieties directly in
to the polymer backbone or enhancement of the emission efficiency by attemp
ts to influence film morphology an some examples of recent research directi
ons. All these investigations contributed to a significantly better underst
anding of the chemical and physical processes spanning topics from the manu
facturing process to the operation of LEDs and leading to the announcement
of the first commercial products. In addition to the classical pi -conjugat
ed polymers a few examples of rather unusual structures have also emerged.
(C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier
SAS.