The Comparison of Photocurrent and Luminance Degradation to Estimate the Lifetime of OLED.

Organic Light Emitting Diode (OLED) degradation is one of the main issues that the industry has to face in order to make a reliable device having sufficiently long lifetime. The lifetime estimation method described in IEC 62341-5-3 was not proper for the OLED materials developers. Some OLED degradation testing systems equip with photodiode, and the photocurrent of test device can be monitored in real time. In this study, the photocurrent degradation was compared with the luminance degradation of OLED devices. The degradation curves using the photocurrent were similar to the curves from luminance measurement, and coefficients of photocurrent degradation and luminance degradation were very similar. The estimated lifetimes calculated from photocurrent degradation were also similar to the values calculated by luminance experimental data. So, it could be concluded that the photocurrent experimental data can be used to estimate the lifetime of OLEDs.