ZnSe/ZnS Core/Shell Quantum Dots with Superior Optical Properties through Thermodynamic Shell Growth
ZnSe/ZnS Core/Shell Quantum Dots with Superior Optical Properties through Thermodynamic Shell Growth
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DOI：
10.1021/acs.nanolett.9b05020
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发表时间：
2020-04-08
期刊：
影响因子：
10.8
通讯作者：
Banin, Uri
中科院分区：
文献类型：
--
作者：
Ji, Botao;Koley, Somnath;Banin, Uri
在胶体量子点（QD）核上外延生长保护性半导体壳是实现高荧光量子效率和基本稳定性的关键策略，用于光电应用和使用发射性QD的生物标记。本文研究了壳层生长速率对窄线宽蓝色发光ZnSe/ZnS量子点结构和光学性质的影响。调整前体的反应性修改的生长模式的ZnS壳的ZnSe核从动力学（快速）到热力学（缓慢）的增长制度转变。在热力学生长机制中，实现了增强的荧光量子产率和减少的开关闪烁。这种高性能归因于有效避免了在核和壳之间的界面处的陷阱，这对发射性能是不利的。我们的研究指出了一个一般的策略，以获得高品质的核/壳量子点，通过控制反应性产生壳生长的热力学极限增强的光学性能。
Epitaxial growth of a protective semiconductor shell on a colloidal quantum dot (QD) core is the key strategy for achieving high fluorescence quantum efficiency and essential stability for optoelectronic applications and biotagging with emissive QDs. Herein we investigate the effect of shell growth rate on the structure and optical properties in blue-emitting ZnSe/ZnS QDs with narrow emission line width. Tuning the precursor reactivity modifies the growth mode of ZnS shells on ZnSe cores transforming from kinetic (fast) to thermodynamic (slow) growth regimes. In the thermodynamic growth regime, enhanced fluorescence quantum yields and reduced on-off blinking are achieved. This high performance is ascribed to the effective avoidance of traps at the interface between the core and the shell, which are detrimental to the emission properties. Our study points to a general strategy to obtain high-quality core/shell QDs with enhanced optical properties through controlled reactivity yielding shell growth in the thermodynamic limit.