Enhancement of OLED Efficiencies and High-Voltage Stabilities of Light-Emitting Materials by Deuteration

Deuterated aluminum 8-hydroxyquinoline (D-Alq3) and bis(2-methyl-8-quinolinolato)(2,6-dimethylphenolato)aluminum(III) (D-Q2AlOAr) were prepared and their electroluminescence devices were fabricated. It was found that deuterium replacement has resulted in a ∼280% increase in the external quantum efficiency at 500 mA/cm2 in the case of Alq3 and ∼270% increase at 150 mA/cm2 in the case of Q2AlOAr device. The deuterated devices have lower turn-on voltages and lower deterioration rates in the electroluminescence (EL) brightness, as compared to the corresponding protonated devices. Deuteration also leads to a better high-voltage stability in D-Alq3 but not in D-Q2AlOAr.