Operating lifetime is the main problem that complicates the use of pol
ymeric light-emitting diodes (LEDs). A class of electron transport (ET
) polymers [poly(aryl acrylate) and poly(aryl ether)s] is reported in
which moieties with high electron affinities are covalently attached t
o stable polymer backbones. Devices based on poly(p-phenylenevinylene)
(PPV) prepared with these materials exhibited a 30-fold improvement i
n stability and, in one case, dramatically lower (10 volts versus abou
t 30 volts) operating voltage relative to those having conventional ET
layers. The current-carrying capacity of indium tin oxide-PPV-polymer
ic ET layer-aluminum LEDs was also increased by a factor of 30. These
improvements lead to an enhancement in power efficiency of nearly an o
rder of magnitude. Choosing polymers with high glass transition temper
atures increases device lifetime.