Kinetically driven selective growth of InAs quantum dots on GaAs
Kinetically driven selective growth of InAs quantum dots on GaAs
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DOI：
10.1557/jmr.2013.340
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发表时间：
2013-12
影响因子：
2.7
通讯作者：
F. Arciprete;E. Placidi;R. Magri;D. Del Gaudio;F. Patella
中科院分区：
文献类型：
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作者：
F. Arciprete;E. Placidi;R. Magri;D. Del Gaudio;F. Patella
结果表明，在温度高于530℃、As/In流量比较高的波纹衬底上，通过改变和调节As流量的方向，可以在GaAs上选择性地生长InAs点。这是一种未知的效应，它与分子束外延生长的InAs量子点(QD)中的砷通量有关。由于土丘的缓坡(1-3°)，这种效应不能用阴影效应来解释，相反，它揭示了As在这些生长条件下发挥着基本作用。我们建立了一个动力学模型，它考虑了阳离子和阴离子之间的耦合，发现由于堆积表面的倾斜蒸发，阴离子通量中很小的表面梯度是导致阳离子大量流失到表面阴离子富集区的原因，从而产生了量子点的选择性生长。
We show that, by changing and tuning the direction of the As flux on a rippled substrate, at temperatures higher than 530 °C and high As/In flux ratio, a selective growth of InAs dots can be obtained on GaAs. This is an undisclosed effect related to the Arsenic flux in the molecular beam epitaxial growth of InAs quantum dots (QDs) on GaAs(001). This effect cannot be explained by a shadowing effect, due to the gentle slopes of the mounds (1–3°), and reveals instead that As plays a fundamental role at these growth conditions. We have developed a kinetic model, which takes into account the coupling between cations and anions, and found that the very small surface gradient in the anion flux, due to the oblique evaporation on the mounded surface, is responsible for a massive drain of cations toward the surface anion-rich areas, thus generating the selective growth of QDs.