22 HIGH PERFORMANCE POLYMERS
the bilayerinterface in addition to the exciton emission
from C12O-PPP [142]. The efficiency varies with the
temperature. At low temperatures, the intensity of the
exciton emission becomes dominant over the intensity
of the exciplex emission.
White light emission can be obtained with multi-
layer devices of different colors [143]. A multilayer
device consisting of ITO, PVK 1,1,4,4-tetraphenyl-
1,3-butadiene/8-(quinolinolate)-aluminum that is
doped with 5,6,11,12-tetraphenylnaphthacene emits
white light in high brightness and with high effi-
ciency [144].
1.4.2.10 Other Chromophores
Pyrazolo-based organic materials belong to the
most promising blue electroluminescent and transport-
ing materials. A series of pyrazoloquinoline deriv ...