Porphyrin doping of Alq3 for electroluminescence

Organic light emitting devices based on tris(8-hydroxyquinoline)aluminium (Alq3) doped with two fluorescent porphyrin derivatives, 5,15-diphenyl-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin and the corresponding zinc metalated one, were fabricated. As a consequence, the light emission changed, from standard green light from Alq3, to reddish and yellowish white respectively. The different spectral content in the two cases indicates a possible route to a white light emitter, based on several dopants from the same family of molecules with different central atoms. The turn-on voltage of the devices was not increased by the doping.