Reducing Emission Linewidth of Pure‐Blue ZnSeTe Quantum Dots through Shell Engineering toward High Color Purity Light‐Emitting Diodes (Small 45/2023)

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).