Efficient green quantum dot light-emitting diodes enabled by high-quality alloyed gradient CdSeS/CdS/ZnS core/shell quantum dots

Cd-based quantum dot light-emitting diodes (QLEDs) have outstanding optical properties, which are promising for a wide range of applications in the fields of lighting and display. However, it is still a research hotspot to prepare high-quality quantum dots (QDs) which can satisfy the requirements of preparing high-performance devices. Here, we develop a facile method to prepare high-quality alloyed CdSeS/CdS/ZnS QDs with a single precursor material, and the as-prepared alloyed QDs have high luminous intensity and narrow size distribution. The alloyed QDs have a uniform and gradient internal structure, there is no abrupt boundary in the final alloyed QDs. This is beneficial to reducing the carrier injection barrier and improving the carrier injection efficiency of electroluminescent devices. The alloyed gradient core/shell QDs-based green QLEDs were fabricated successfully and maximum current efficiency of 33.7 cd/A was obtained. This paper will provide a new strategy to prepare high-performance QLED devices.