IDW’20 OLED5-4L: The essence of emission zone measurement
The members of OPERA Solutions published a paper regarding the essence of emission zone measurement. Accelerated OLED ageing at higher current densities is commonly used to extrapolate lower current density device lifetime benchmarks. It was found that the conventional accelerated ageing assumption and extrapolation method cannot be relied upon. If the accelerated ageing extrapolation is used, errors as high as 233% result.
Different emission zones and device ageing were measured at different current densities giving more insight into the suitability of such accelerated ageing assumptions. For the devices in this work, different degradation effects are evident at different current densities which seems to be caused by a changing emission zone. The methods of this paper can be easily transferred to a study on fluorescent OLEDs, phosphorescent OLEDs and even Perovskite LEDs.