Centrosymmetric PbTe∕CdTe quantum dots coherently embedded by epitaxial precipitation
Centrosymmetric PbTe∕CdTe quantum dots coherently embedded by epitaxial precipitation
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DOI：
10.1063/1.2202107
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发表时间：
2006-02
影响因子：
4
通讯作者：
Wolfgang Heiss;H. Groiss;E. Kaufmann;G. Hesser;M. Böberl;G. Springholz;Friedrich Schäffler;K. Koike;H. Harada;M. Yano
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文献类型：
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作者：
Wolfgang Heiss;H. Groiss;E. Kaufmann;G. Hesser;M. Böberl;G. Springholz;Friedrich Schäffler;K. Koike;H. Harada;M. Yano
演示了制造相干嵌入单晶基质中的高度对称量子点的概念。在这种方法中，量子点的形成是通过将外延二维量子阱转变为尺寸约为25nm的孤立沉淀物阵列来诱导的。形成过程是由不同晶格结构导致的组成材料的不混溶性驱动的。研究的 PbTe∕CdTe 异质系结合了两种不同的立方晶格，晶格常数几乎相同。因此，沉淀的量子点几乎是无应变的，并且接近热力学平衡，它们呈现出小菱形立方八面体的形状。在 GaAs 基底上生长的 PbTe∕CdTe 量子点在波长约为 3.2μm 时表现出强烈的室温发光，这使得它们非常适合在中红外光子器件中应用。
A concept for the fabrication of highly symmetric quantum dots that are coherently embedded in a single crystalline matrix is demonstrated. In this approach, the formation of the quantum dots is induced by a transformation of an epitaxial two dimensional quantum well into an array of isolated precipitates with dimensions of about 25nm. The formation process is driven by the immiscibility of the constituent materials resulting from their different lattice structures. The investigated PbTe∕CdTe heterosystem combines two different cubic lattices with almost identical lattice constants. Therefore, the precipitated quantum dots are almost strain-free and near thermodynamic equilibrium they exhibit the shape of small-rhombo-cubo-octahedrons. The PbTe∕CdTe quantum dots, grown on GaAs substrates, display intense room temperature luminescence at wavelength of around 3.2μm, which makes them auspicious for applications in midinfrared photonic devices.