Heavy-metal-free blue-emitting ZnSe(Te) quantum dots: synthesis and light-emitting applications

Abstract

Colloidal quantum dots (QDs) possess superb optoelectronic properties, making them suitable as light emitters. However, the toxicity of classical Cd/Pb QDs with high luminescence efficiency restricts their further industrial light-emitting applications. Heavy-metal-free ZnSe(Te) QDs are regarded as the most promising alternative to Cd/Pb-based QD blue emitters, which are expected to solve the problems through which InP QDs struggle to achieve efficient blue emission. However, the realization of ZnSe(Te) QDs and light-emitting devices with high efficiency, high stability, and narrow emission faces huge challenges. In this review, the synthesis of ZnSe(Te) QDs is reviewed, and their improvement strategies including bandgap engineering and surface passivation are introduced and discussed. The progress regarding blue ZnSe(Te)-based light-emitting applications is summarized. Finally, a brief outlook is provided, highlighting the current challenges being faced, their possible solutions, and future development directions.