P‐129: The Black Spot Phenomenon and Improvement in QLED Devices

In this paper, we studied the influence of ETL (electron transporting layer)and cathode material type as well as their interface on the performance of QLED (quantum dot light emitting devices). Through our research, we found that the black spot phenomenon of QLED device is strongly related to ETL material, and the number of black spots can be greatly reduced by improve ETL. In addition, the cathode material such as Ag and Al, also show their impact on black spots; Finally, one novel double‐layer ETL structure device was developed to avoid black spot, which manifest that the interaction between ETL and the electrode interface also play an important role. The absence of black spots in inverted devices also proves this conclusion.