Aj. Epstein et al., POLY(P-PYRIDINE)-BASED AND POLY(P-PYRIDYL-VINYLENE)-BASED POLYMERS - THEIR PHOTOPHYSICS AND APPLICATION TO SCALE DEVICES, Synthetic metals, 78(3), 1996, pp. 253-261
Photophysics and light-emitting device applications of poly(p-pyridine
)- and poly(p-pyridyl vinylene)-based polymers are presented. Extensiv
e time-resolved (ps to ms) photoluminescence, stimulated emission and
photoinduced absorption studies of solutions, powders and films demons
trate that the primary photoexcitation of these polymers is an intrach
ain singlet exciton. The presence of (n,pi) states leads to enhanced
intersystem crossing to triplet excitons for the powder form, while ag
gregate formation plays a key role in the films. Polarons are importan
t at longer times. These polymers were used to fabricate 'conventional
' polymer light-emitting diodes. In addition, these polymers were used
to demonstrate a novel light-emitting structure, the symmetrically co
nfigured a.c. light-emitting (SCALE) device. These new devices have po
tential advantages in their use with high workfunction electrodes, suc
h as gold, and also in their a.c. operation.