Red organic electroluminescence devices with a reduced porphyrin compound,tetraphenylchlorin

We constructed red organic electroluminescence (EL) devices with a reduced porphyrin compound, tetraphenylchlorin, that was doped at various concentra tions (0.5, 1.7, and 3.7 wt %) within a tris(8-hydroxyquinoline) aluminum ( Alq3) host layer. We measured their EL properties and found that all three devices emitted a red EL band at 660 nm with a width of 20 nm. Emission col or of the 1.7 and 3.7 wt % devices was red (chromaticity coordinates x=0.67 , y=0.29 and x=0.78, y=0.21) and the luminance maximum was 100 and 24 cdm(- 2), respectively. The 0.5 wt % device emitted a green Alq3 EL band as well, and showed an increase in relative intensity of the Alq3 emission with inc reasing applied voltage. (C) 1999 American Institute of Physics. [S0003-695 1(99)01618-6].