Mr. Pinto et al., Emitting polymers containing cyano groups. Synthesis and photophysical properties of a fully conjugated polymer obtained by Wittig reaction, POLYMER, 41(22), 2000, pp. 8095-8102
A new electroluminescent fully conjugated, substituted PPV-related structur
e was synthesized. The ring-substituted units (2,5 hexadecyloxy and 2,5 cya
no) were interspersed by one non-substituted PPV unit. The EL emission was
centered at 612 nm (orange). Double layer devices using PPV as a hole-trans
porting material showed 3000 cd/m(2) at a 20 V bias.
In addition to the better transport characteristics imparted by the PPV lay
er, Forster transfer at the interface provided a better light output in the
se devices in comparison with single layer LEDs. Increases in PPV thickness
yielded a slight blue shift suggesting that emission from the bulk PPV was
occurring as well. (C) 2000 Elsevier Science Ltd. All rights reserved.