Influence of Interface-Driven Strain on the Spectral Diffusion Properties of Core/Shell CdSe/CdS Dot/Rod Nanoparticles
Influence of Interface-Driven Strain on the Spectral Diffusion Properties of Core/Shell CdSe/CdS Dot/Rod Nanoparticles
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DOI：
10.1021/acs.jpcc.8b12253
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发表时间：
2018-07
期刊：
影响因子：
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通讯作者：
S. Lohmann;P. Harder;F. Bourier;C. Strelow;A. Mews;T. Kipp
中科院分区：
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作者：
S. Lohmann;P. Harder;F. Bourier;C. Strelow;A. Mews;T. Kipp
通过结合原子价力场方法和基于有效质量近似的计算，我们研究了应变效应对核/壳CdSe/CdS点/棒纳米颗粒能带排列和一般激子性质的影响。我们发现，应变效应的列入导致激子能量的增加，以及减少电子和空穴波函数重叠。重要的是，CdSe/CdS材料系统的天然I型能带排列被保留，并且不会改变为纳米颗粒的准II型或甚至II型能带偏移。此外，我们分析了应变对这些纳米颗粒的荧光发射的光谱扩散的影响，这是由迁移的表面电荷来解释的。我们的计算表明，应变效应的增加导致增加的能量转移，以及更大的变化，在平方电子和空穴波函数重叠，而两者的相关性也表现出比...
By combining an atomistic valence force field approach and calculations based on the effective-mass approximation, we investigate the influence of strain effects on the band alignment and general excitonic properties of core/shell CdSe/CdS dot/rod nanoparticles. We find that the inclusion of strain effects leads to an increase in the exciton energy as well as to a decrease in the electron and hole wave function overlap. Importantly, the native type-I band alignment of the CdSe/CdS material system is preserved and does not change into a quasi-type-II or even type-II band offset for the nanoparticles. Furthermore, we analyze the impact of strain on the spectral diffusion of the fluorescence emission of these nanoparticles, which is explained by migrating surface charges. Our calculations show that the addition of strain effects leads to increased energy shifts as well as larger changes in the squared electron and hole wave function overlap, whereas the correlation of both also exhibits a steeper slope than ...