Mitigating Surface Energy and Core‐Shell Interface Strain of Yb 3+ ‐Doped ZnSe‐Based Quantum Dots for Pure‐Blue Emission QLED Devices

This is the authors' abstract. We don't add key points for this paper.

Large ZnSe quantum dots (QDs) with an emission peak ≈450 nm hold significant promise for display technologies. However, achieving efficient pure‐blue emission through the enlargement of ZnSe nanocrystals remains a significant challenge. In this study, a breakthrough is reported in growing large‐size ZnSe QDs well beyond the exciton Bohr radius through Yb 3+ doping strategy. Yb 3+ doping reduces the surface energy of the ZnSe (220) crystal plane and alleviates interface strain in the ZnSe/ZnS structure, enabling the QDs to grow larger while maintaining enhanced crystal stability. The resulting Yb: ZnSe/ZnS QDs exhibit pure‐blue emission at 453 nm, with a full width at half maximum (FWHM) of 46 nm and a high photoluminescence quantum yield (PLQY) of 67.5%. When integrated into quantum dot light‐emitting diodes (QLEDs), the devices display electroluminescence (EL) at 455 nm, with an external quantum efficiency (EQE) of 1.35%, and a maximum luminance of 1337.08 cd m −2 .