P‐127: Improving the Driving Voltage Stability of Tandem Red OLED

Tandem OLED device structure could effectively reduce the OLED working current and thus achieve the effect of reducing the OLED power consumption. At the same time, tandem OLED device structure could achieve higher outdoor brightness, reduce battery capacity and reduce the risk of burn‐in effect of OLED display. Therefore, tandem OLED device structure would have a wide range of applications in the future. However, the side effects of tandem OLED device structure are raised the driving voltage and reduced the voltage stability of the device. Our work is to mitigate that side effect. In this paper, the voltage stability of 2‐ unit top‐emitting tandem red OLED was optimized through material screening and structural adjustment. After 300 hours of operation, the variation of voltage has dropped form 0.167 V to 0.085 V at 10 mA/cm 2 . The driving voltage of tandem red OLED had also decreased by 0.25 V.