GaSb quantum dot morphology for different growth temperatures and the dissolution effect of the GaAs capping layer
GaSb quantum dot morphology for different growth temperatures and the dissolution effect of the GaAs capping layer
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DOI：
10.1088/0022-3727/43/6/065402
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发表时间：
2010-01
期刊：
影响因子：
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通讯作者：
M. A. Kamarudin;M. Hayne;Q. Zhuang;O. Kolosov;T. Nuytten;V. Moshchalkov;F. Dinelli
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文献类型：
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作者：
M. A. Kamarudin;M. Hayne;Q. Zhuang;O. Kolosov;T. Nuytten;V. Moshchalkov;F. Dinelli
本文比较了在400 ~ 490℃温度下，GaAs上分子束外延生长的GaSb量子点的特性。通过原子力显微镜（AFM）对未封盖量子点的大小、形状和密度进行测定，发现其点形态对生长温度高度敏感。封顶QD的光致发光（PL）光谱也强烈依赖于生长温度，但对于具有最高点密度的样品，QD发光将是最强烈的，它是不存在的。我们认为这是由于覆盖层溶解了点。这一解释被AFM样品在490°C薄盖证实。在低温下沉积盖层解决了这一问题，从而从具有高点密度的样品中产生强量子点发光。
We compare the characteristics of GaSb quantum dots (QDs) grown by molecular beam epitaxy on GaAs at temperatures from 400 to 490 °C. The dot morphology, in terms of size, shape and density, as determined by atomic force microscopy (AFM) on uncapped QDs, was found to be highly sensitive to the growth temperature. Photoluminescence (PL) spectra of capped QDs are also strongly dependent on growth temperature, but for samples with the highest dot density, where the QD luminescence would be expected to be the most intense, it is absent. We attribute this to dissolution of the dots by the capping layer. This explanation is confirmed by AFM of a sample that is thinly capped at 490 °C. Deposition of the capping layer at low temperature resolves this problem, resulting in strong QD PL from a sample with a high dot density.