Shape and composition map of a prepyramid quantum dot.
Shape and composition map of a prepyramid quantum dot.
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DOI：
10.1103/physrevlett.95.206101
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发表时间：
2005-11
影响因子：
8.6
通讯作者：
Brian Spencer;M. Blanariu
中科院分区：
文献类型：
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作者：
Brian Spencer;M. Blanariu
我们提出了一个理论的形状，尺寸和不均匀的成分分布的一个小prepyramid岛在合金外延膜时，表面扩散比沉积和体扩散快得多。预测的成分分布具有较大的错配组分向岛峰的偏析，偏析由错配应变和溶质应变增强，但由合金溶液热力学延迟。由于这种机制，通过岛中心的垂直成分梯度对于Ge（X）Si（1-X）/Si为2%/nm的量级，对于In（X）Ga（1-X）As/GaAs为10 - 15%/nm的量级。
We present a theory for the shape, size, and nonuniform composition profile of a small prepyramid island in an alloy epitaxial film when surface diffusion is much faster than deposition and bulk diffusion. The predicted composition profile has segregation of the larger misfit component to the island peak, with segregation enhanced by misfit strain and solute strain but retarded by alloy solution thermodynamics. Vertical composition gradients through the center of the island due to this mechanism are on the order of 2%/nm for Ge(X)Si(1-X)/Si and 10-15%/nm for In(X)Ga(1-X)As/GaAs.