Research progress and challenges of blue light-emitting diodes based on II-VI semiconductor quantum dots

Light-emitting diodes based on II-VI semiconductor quantum dots (QDs) have attracted considerable attention due to their superior features of color tunability, high brightness, narrow emission bandwidths, solution processing capabilities and compatibility with flexible substrates. The efficiencies and stabilities of red and green quantum-dot light-emitting diodes (QLEDs) are close to the standard for commercial applications, while blue QLEDs lag behind in device efficiency and stability. This paper reviews the latest progress of blue luminescent materials and devices based on II-VI semiconductor QDs, covering the latest progress in the synthesis of blue QDs, device structures, carrier transport materials, interface regulation, and light outcoupling technology. Furthermore, the current problems and solutions of blue QLEDs are discussed, and the development and application prospects of blue QLEDs are summarized. Key issues and challenges associated with the application of QLEDs in flat-panel displays are also identified.