Correlation of In–Ga intermixing with band-tail states in InAs∕GaAs quantum dots
Correlation of In–Ga intermixing with band-tail states in InAs∕GaAs quantum dots
复制标题
InAs∕GaAs量子点中In-Ga混合与带尾态的相关性
DOI：
10.1063/1.2839376
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
L. Hsu
中科院分区：
文献类型：
--
作者：
Hung;Y. Lai;Chuan;Y. Lai;Y. Fang;L. Hsu
用能量过滤透射电子显微镜(EFTEM)的光谱成像(SI)方法研究了InAs/GaAsSTranski-Krastanov量子点(QD)的表面和埋层的形状和成分分布。来自EFTEM SI的铟图显示了表面和埋藏量子点的透镜和截断的金字塔形状，埋藏量子点的成分变化增加。光致发光测量表明，在1.075 eV处的发射与被掩埋的量子点中的受限态有关，同时伴随着高能肩，与被掩埋的量子点附近In-Ga混合导致的带尾态有关。
We have investigated the shape and composition profiles of buried and surface InAs∕GaAs Stranski–Krastanov quantum dots (QDs) by using the spectrum-imaging (SI) method with energy-filtered transmission electron microscopy (EFTEM). Indium maps from EFTEM SI reveal lens and truncated pyramid shapes for the surface and buried QDs, with an increase in composition variations for the buried QDs. Photoluminescence measurements reveal an emission at 1.075eV, associated with confined states in the buried QDs, along with a high energy shoulder, associated with band-tail states due to In–Ga intermixing in the vicinity of the buried QDs.