Low Energy-Consumption Inverted Orange Organic Light-Emitting Diodes with Reduced Efficiency Roll-Off

Inverted organic light-emitting diodes (IOLEDs) have a bottom cathode, making them convenient to integrate with the preferred n-type active matrix OLED driving technologies. Furthermore, inverted OLEDs show much better air-stability compared with conventional OLEDs, due to the very reactive and sensitive of alkali doped electron injection layer (EIL) towards ambient oxygen and moisture. For inverted OLEDs, the bottleneck to limit their efficiency and stability is the interface at cathode/EIL and light emitting layer (EML)/charge transporting layer. In this paper, we have investigated the effect of different electron/hole transporting layers on the turn-on voltage, efficiency roll-off and power consumption of inverted orange OLEDs. We found that the device exhibits extremely-low efficiency roll-off and a significant lifetime improvement.