Indium segregation in ultra-thin In(Ga)As/GaAs single quantum wells revealed by photoluminescence spectroscopy
Indium segregation in ultra-thin In(Ga)As/GaAs single quantum wells revealed by photoluminescence spectroscopy
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DOI：
10.1063/5.0039107
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发表时间：
2021-02
影响因子：
4
通讯作者：
Y. Maidaniuk;R. Kumar;Y. Mazur;A. Kuchuk;M. Benamara;P. Lytvyn;G. Salamo
中科院分区：
文献类型：
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作者：
Y. Maidaniuk;R. Kumar;Y. Mazur;A. Kuchuk;M. Benamara;P. Lytvyn;G. Salamo
介绍了一种非破坏性的方法，适用于研究超薄In（Ga）As/GaAs纳米结构的分子束外延生长的In偏析现象。所提出的方法只利用实验的光致发光（PL）光谱数据和有效的带隙模拟专门设计的超薄In（Ga）As/GaAs纳米结构。以InAs和In0.25Ga0.75As量子威尔斯阱为例，分别计算了1个单层（ML）和4个单层（ML）的In分凝系数，并与STEM（扫描透射电子显微镜）的Z衬度截面成像结果进行了比较，结果表明该方法与STEM（扫描透射电子显微镜）的Z衬度截面成像结果具有良好的相关性.然而，PL与STEM相比具有显着的优势，因为它是一种用于测量多个样品或大面积的无损，可靠和快速的技术。此外，在超薄In（Ga）As/GaAs纳米结构中的In偏析的调谐，以及通过改变生长温度或低温GaAs覆盖层的厚度来修改和控制In深度分布轮廓的可能性，被另外证明。铟偏析的详细分析允许设计和精确生长的超薄In（Ga）As/GaAs纳米结构的激光器，太阳能电池和红外光电探测器。
A nondestructive approach is described that is applicable for studying the In-segregation phenomena in ultra-thin In(Ga)As/GaAs nanostructures grown by molecular beam epitaxy. The proposed method utilizes only the experimental photoluminescence (PL) spectroscopy data and the effective bandgap simulation of specially designed ultra-thin In(Ga)As/GaAs nanostructures. On the example of InAs and In0.25Ga0.75As quantum wells with thicknesses of 1 monolayer (ML) and 4 MLs, respectively, a good correlation for the In segregation coefficient obtained from the proposed method and STEM (scanning transmission electron microscope) Z-contrast cross section imaging is demonstrated. However, PL has a significant advantage over STEM for being a nondestructive, reliable, and rapid technique for measuring multiple samples or large areas. Furthermore, tuning of In segregation in ultra-thin In(Ga)As/GaAs nanostructures, as well as the possibility of modifying and controlling the In depth-distribution profile by the change of growth temperature or the thickness of the low-temperature GaAs capping layer, are additionally demonstrated. A detailed analysis of indium segregation allows the design and precise growth of ultra-thin In(Ga)As/GaAs nanostructures for lasers, solar cells, and infrared photodetectors.