Bulk-like ZnSe Quantum Dots Enabling Efficient Ultranarrow Blue Light-Emitting Diodes
Bulk-like ZnSe Quantum Dots Enabling Efficient Ultranarrow Blue Light-Emitting Diodes
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块状 ZnSe 量子点可实现高效超窄蓝色发光二极管
DOI：
10.1021/acs.nanolett.1c02284
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发表时间：
2021-08-24
期刊：
影响因子：
10.8
通讯作者：
Du, Zuliang
中科院分区：
文献类型：
--
作者：
Gao, Min;Yang, Huawei;Du, Zuliang
蓝色发射重金属的无QD同时表现出接近统一的光致发光量子屈服，而窄发射线宽度对于下一代电致发光显示至关重要，但它们的合成却是高度挑战性的。本文中，我们通过在ZnSe芯上生长薄薄的Zns壳来发展蓝色发射QD的合成，其大小大于块状bohr直径。 ZNSE核心的宽大尺寸使发射能够在蓝色区域定位，其发射宽度接近其内在的峰宽度。所获得的散装ZNSE/ZNS Core/Shell QD显示出高量子收率为95％，并且非常窄的发射宽度与9.6 nm相似。此外，ZNSE核心的散装大小可降低LED中QD和相邻层之间的能级差异，并改善电荷运输。用这些高质量的QD制造的LED显示出明亮的纯蓝色发射，外部量子效率为12.2％，工作寿命相对较长。
Blue-emitting heavy-metal free QDs simultaneously exhibiting photoluminescence quantum yield close to unity and narrow emission line widths are essential for next-generation electroluminescence displays, yet their synthesis is highly challenging. Herein, we develop the synthesis of blue-emitting QDs by growing a thin shell of ZnS on ZnSe cores with their size larger than bulk Bohr diameter. The bulk-like size of ZnSe cores enables the emission to locate in the blue region with a narrow emission width close to its intrinsic peak width. The obtained bulk-like ZnSe/ZnS core/shell QDs display high quantum yield of 95% and extremely narrow emission width of similar to 9.6 nm. Moreover, the bulk-like size of ZnSe cores reduces the energy level difference between QDs and adjacent layers in LEDs and improves charge transport. The LEDs fabricated with these high-quality QDs show bright pure blue emission with an external quantum efficiency of 12.2% and a relatively long operating lifetime.