Degradation of organic light emitting diodes with cleaned ITO and MoO3 hole-injection layer

We study the effect of indium tin oxide (ITO) cleaning and hole-injection layer (HIL) insertion on performance of organic light emitting diodes (OLEDs) device, especially the degradation. We prepare higher- and lower-level cleaned ITOs and molybdenum oxide (MoO3) as HIL. OLED with higher-level cleaned ITO and without MoO3 gives the lower driving voltage, while a good stability in chromaticity and power efficiency is obtained from OLEDs with MoO3. The degradation of power efficiency is reduced in OLEDs with MoO3 and lower-level cleaned ITO.