Anomalous photoluminescence in CdSe quantum-dot solids at high pressure due to nonuniform stress
Anomalous photoluminescence in CdSe quantum-dot solids at high pressure due to nonuniform stress
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DOI：
10.1002/smll.200701097
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发表时间：
2008-06-01
期刊：
影响因子：
13.3
通讯作者：
Zaitseva, Natalia
中科院分区：
文献类型：
--
作者：
Grant, Christian D.;Crowhurst, Jonathan C.;Zaitseva, Natalia
静态高压的应用提供了一种精确控制和研究纳米颗粒许多基本和独特性质的方法。 CdSe 是一种模型量子点系统，其在高压下的行为已被广泛研究；然而，不均匀应力对该系统的影响尚未得到充分认识。给出了从纯均匀到高度不均匀的不同应力环境下从 CdSe 量子点固体获得的光致发光数据。均匀应力分布的微小偏差会深刻影响该系统的电子特性。在非均匀应力环境中，在 3 GPa 以上时观察到光致发光能量明显平坦化。这些观察结果通过使用全原子半经验赝势技术获得的理论计算得到了验证。在研究其他潜在的压力介导现象时必须考虑这种效应。
The application of static high pressure provides a means to precisely control and investigate many fundamental and unique properties of nanoparticles. CdSe is a model quantum-dot system, the behavior of which under high pressure has been extensively studied; however, the effect of nonuniform stresses on this system has not been fully appreciated. Photoluminescence data obtained from CdSe quantum-dot solids in different stress environments varying from purely uniform to highly nonuniform are presented. Small deviations from a uniform stress distribution profoundly affect the electronic Properties of this system. In nonuniform stress environments, a pronounced flattening of the photoluminescence energy is observed above 3 GPa. The observations are validated with theoretical calculations obtained using an all-atom semiempirical pseudopotential technique. This effect must be considered when investigating other potentially pressure-mediated phenomena.