Top-Emission ZnSeTe/ZnSe/ZnS-Based Blue Quantum Dot Light- Emitting Diodes with Enhanced Chroma Efficiency

A high-performance quantum dot light-emitting diode (QLED) with heavy metal free (HMF) quantum dots (QDs) is urgently needed for its application in next generation eco-friendly displays. However, the preparation of high-performance HMF QD materials and the corresponding electroluminescent devices remain challenges at present, especially for blue-emitting devices. In this work, by adjusting the Te/Se ratio of the ZnSeTe core, ZnSeTe/ZnSe/ZnS blue QDs with adjustable energy levels and emission peaks are demonstrated. These QDs are utilized to fabricate top-emitting QLEDs, yielding a peak current efficiency (CE) of 11.8 cd A(-1). To make it one step further to meet the requirement of the wide color gamut in displays, the devices' color coordinates and current efficiency are simultaneously optimized by adjusting their microcavity structure and electrical properties. Finally, the chroma efficiency (current efficiency/CIEy) of the blue devices is optimized to 72, which is 2.2 times that of the control device.

Automated summary

Researchers have successfully developed a high-performance, heavy metal-free quantum dot light-emitting diode for eco-friendly displays. By adjusting the ratio of Te/Se in the core, they were able to create blue quantum dots with adjustable energy levels and emission peaks. By optimizing the microcavity structure and electrical properties, they achieved a chroma efficiency of 72 for the blue devices, which is 2.2 times higher than the control device.