Degradation mechanism of OLEDs based on AlQ3

Injection of holes into AlQ3 was identified as the main factor responsible for device degradation. Further studies using time-resolved fluorescence of AlQ3 based devices show that the AlQ3 degradation products are fluorescence quenchers, which cause decrease in device efficiency during prolonged operation. Simultaneous measurements of photoluminescence (PL) and electroluminescence (EL) decay show that PL decay is consistently smaller than EL decay indicating that PL decay is not the only mechanism leading to EL degradation of AlQ3.