Warm and Neutral White OLEDs Aging Comparison Studies under Electrical and Thermal Stress

Nowadays, Organic Light Emitting Diode (OLED) panels are widely used for displays from smartphone to TV or tablets but, due to numerous qualities (high color rendering index, high efficiency, bendable, no glare, etc.), this kind of light sources is more and more seen as the next generation of wide usage light source. If the color temperature shows well-known effects on the human circadian cycle which should lead to specific usage, this color temperature is due to the composition of the emissive layer. This paper presents for the first time a comparative study of luminance and impedance evolution between neutral and warm white large-area OLED panels aged under thermal and electrical stress. The results show that warm white OLEDs developed the fastest degradation compared to neutral white families. Therefore, the Correlated Color Temperature (CCT) is an important factor in the aging of OLEDs, like current and temperature.