Phosphorescent Organic Light-Emitting Diodes Based on a Red Cu(I) Complex

The photoluminescence and electroluminescence properties of red Cu(Ⅰ) complex (BF_(4))(dbp=2,9-Di-tert-butyl-1,10-phenanthroline;dmp=2,9-Dimethyl-1,10-phenanthroline) were studied.The film of 20% Cu(Ⅰ) complex in PMMA exhibited a photoluminescence quantum yield of 5% with emission maximum at 617 nm.A short excited-state lifetime of 1.7 μs was also observed.Phosphorescent OLEDs with red emission identical to photoluminescence spectrum of the complex in PMMA film were fabricated by using poly(vinyl carbazole)(PVK) as host.A current efficiency of 0.9 cd/A along with a(maximum) brightness up to 631 cd/m~(2) was demonstrated.The triplet-triplet(T-T) annihilation under a high current density was not significant for these devices and might be attributed to the short excited-state lifetime of the(complex).