ZnSeTe Quantum Dots
In article number 2303247, Jialong Zhao, Sheng Cao, Yunjun Wang, and co‐workers propose a strategy for fabricating high‐color purity and high‐efficiency pure blue quantum dot (QD) light‐emitting diodes (QLEDs) using eco‐friendly ZnSeTe/ZnSe/ZnS QDs. Precisely controlling the internal ZnSe shell thickness could weaken the exciton‐ longitudinal optical (LO) phonon coupling strength and reduce trap states in the QDs. The QD shell engineering strategy yields QLEDs with an ultra‐narrow linewidth of 22 nm and an electroluminescent (EL) peak at 452 nm, achieving an external quantum efficiency (EQE) of 18.0%. The Commission Internationale de l'Eclairage (CIE) chromatic coordinates of the QLEDs are measured as (0.148, 0.042).