Multiple stacking of self-assembled InAs quantum dots embedded by GaNAs strain compensating layers
Multiple stacking of self-assembled InAs quantum dots embedded by GaNAs strain compensating layers
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DOI：
10.1063/1.2359623
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发表时间：
2006-10
影响因子：
3.2
通讯作者：
R. Oshima;T. Hashimoto;H. Shigekawa;Y. Okada
中科院分区：
文献类型：
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作者：
R. Oshima;T. Hashimoto;H. Shigekawa;Y. Okada
我们研究了一种在GaAs（001）衬底上实现高质量自组装InAs量子点（QDs）多重堆叠的生长技术，其中GaNxAs1−x稀氮化物材料用作应变补偿层（SCL）。利用原子氢辅助射频分子束外延实现了晶体的生长，并利用高分辨率x射线衍射测量系统地研究了应变补偿的影响。通过在每个QD层上覆盖40 nm厚的GaN0.005As0.995 SCL，将净平均晶格应变控制到最小，我们获得了尺寸均匀性没有退化的优越QD结构。此外，即使堆叠30层也没有产生位错，量子点的面积密度高达3×1012cm−2。由于避免了晶格应变随量子点层生长而累积的现象，使得嵌入在GaNAs scl中的量子点的光致发光峰线宽提高了约22%。
We have investigated a growth technique to realize high-quality multiple stacking of self-assembled InAs quantum dots (QDs) on GaAs (001) substrates, in which GaNxAs1−x dilute nitride material was used as a strain compensation layer (SCL). The growth was achieved by atomic hydrogen-assisted rf molecular beam epitaxy, and the effect of strain compensation was systematically investigated by using high-resolution x-ray diffraction measurements. By controlling the net average lattice strain to a minimum by covering each QD layer with a 40-nm-thick GaN0.005As0.995 SCL, we obtained a superior QD structure with no degradation in size homogeneity. Further, no dislocations were generated even after 30 layers of stacking, and the area density of QDs amounted to as high as 3×1012cm−2. The photoluminescence peak linewidth was improved by about 22% for QDs embedded in GaNAs SCLs as the accumulation of lattice strain with increasing growth of QD layers was avoided, which would otherwise commonly lead to degradation of ...