Voltage-independent pure red devices based on a carbazole-functionalized europium complex

Electroluminescent properties of carzole-founctionized complex tris(dibenzoylmethanato)(1-ethyl-2-(N-ethyl-carbazole-yl-4)imidazo[4,5-f]1,10-phenanthroline)europium(III) (Eu(DBM)3Phencarz) was investigated. By utilizing complex tris(1-phenyl-3-methyl-4-isobutyl-5-pyrazolone)-bis(triphenyl phosphine oxide) gadolinium Gd(PMIP)3(TPPO)2 as electron-transport layer, hole and electron injection was relatively balanced in the emitting layer and a device with the configuration of ITO/TPD (20 nm)/(Eu(DBM)3Phencarz) (40 nm)/Gd(PMIP)3(TPPO) (20 nm)/AlQ (30 nm)/Mg:Ag emitted voltage-independent characteristic europium light with the luminance of 1193 cd/m2, power efficiency 1.68 lm/W.