Effects of lateral quantum dot pitch on the formation of vertically aligned InAs site-controlled quantum dots
Effects of lateral quantum dot pitch on the formation of vertically aligned InAs site-controlled quantum dots
复制标题
横向量子点间距对垂直排列InAs位点控制量子点形成的影响
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
K. Asakawa
中科院分区：
文献类型：
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作者：
Tao Yang;S. Kohmoto;H. Nakamura;K. Asakawa
我们讨论了横向量子点间距对GaAs衬底上用薄间隔层隔开的垂直取向InAs位控量子点（SCQD）形成的影响。基于纳米尺度的位置控制技术和自组织外延，制备了不同量子点阵列间距（100 nm，75 nm，50 nm和40 nm）的InAs SCQD正方形阵列的双层。原位扫描隧道显微镜观察表明，两层SCQD之间的垂直配对概率随着间距的减小而减小，当间距福尔斯低于75 nm时，垂直配对概率急剧减小。此外，室温μ-光致发光测量表明，垂直排列的SCQD双层的线宽随着间距的减小而增加。同样，我们发现当间距福尔斯下降到75 nm以下时，光致发光线宽显著增加。所观察到的结果归因于由第一层埋InAs SCQD引起的弹性应变场之间的横向相互作用。
We discuss the effects of lateral quantum dot pitch on the formation of vertically aligned InAs site-controlled quantum dots (SCQDs) separated by thin spacers on GaAs substrates. Bilayers of InAs SCQD square arrays of various quantum dot-array pitches (100 nm, 75 nm, 50 nm, and 40 nm) are fabricated based on nanometer-scale site-control techniques and self-organizing epitaxy. In situ scanning tunneling microscope observations reveal that the vertical pairing probability between the two layers of SCQDs decreases with decreasing pitch, with a dramatic reduction when the pitch falls below 75 nm. Moreover, room-temperature μ-photoluminescence measurements show that the linewidth of the bilayers of vertically aligned SCQDs increases with declining pitch. Again, we found a remarkable increase in photoluminescence linewidth when the pitch falls below 75 nm. The observed results are attributed to lateral interactions between elastic strain fields induced by the first layer of buried InAs SCQDs.