Modulated reflectivity probing of quantum dot and wetting layer states in InAs/GaInAsP/InP quantum dot laser structures
Modulated reflectivity probing of quantum dot and wetting layer states in InAs/GaInAsP/InP quantum dot laser structures
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InAs/GaInAsP/InP 量子点激光器结构中量子点和润湿层态的调制反射率探测
DOI：
10.1002/pssa.200673325
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
G. Patriarche
中科院分区：
文献类型：
--
作者：
G. Sȩk;M. Motyka;R. Kudrawiec;J. Misiewicz;F. Lelarge;B. Rousseau;G. Patriarche
采用气源分子束外延法在InP（100）衬底上生长InAs/GaInAsP量子点（QD）结构，并将其设计为激光在1.55 μm波长范围内的有源区，利用光谱学研究了其能量电子结构。调制反射率测量（以光反射率- PR的形式）的优点已被用于检测与包层材料、第四层势垒、润湿层和量子点等结构的所有相关部分相关的光学跃迁。我们基于有效质量近似计算的理论分析表明，QD基态发射上方的两个高能PR特征与3-4层厚的InAs润湿层中的重空穴和轻空穴基态转变有关。此外，这些点的约束势足够浅，只能限制一个电子态，因此在PR中观察到单个QD重空穴跃迁（©2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim）。
InAs/GaInAsP quantum dot (QD) structure grown by gas source molecular beam epitaxy on InP (100) substrate and designed as an active region for laser applications at 1.55 μm wavelength range has been investigated by optical spectroscopy in order to probe its energy electronic structure. The advantages of the modulated reflectivity measurements (in a form of photoreflectance – PR) have been used to detect the optical transitions related to all relevant parts of the structure like cladding material, quaternary barriers, wetting layer and finally quantum dots. Our theoretical analysis based on effective mass approximation calculations has shown that two high energy PR features above the QD ground state emission are related to heavy hole and light hole ground state transitions in the InAs wetting layer which is 3–4 monolayers thick. Moreover, the confinement potential for the dots is shallow enough to confine one electron state only and hence a single QD heavy hole transition has been observed in PR. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)