Band-gap energies, free carrier effects, and phonon modes in strained GaNAs/GaAs and GaNAs/InAs/GaAs superlattice heterostructures measured by spectroscopic ellipsometry
Band-gap energies, free carrier effects, and phonon modes in strained GaNAs/GaAs and GaNAs/InAs/GaAs superlattice heterostructures measured by spectroscopic ellipsometry
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通过椭圆偏振光谱法测量应变 GaNAs/GaAs 和 GaNAs/InAs/GaAs 超晶格异质结构中的带隙能量、自由载流子效应和声子模式
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
G. Wagner
中科院分区：
文献类型：
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作者：
J. Šik;M. Schubert;G. Leibiger;V. Gottschalch;G. Wagner
光谱椭圆光度 (SE) 用于研究压缩应变短周期 GaAs/InAs/GaNxAs1−x (0%<x<2.4%) 超晶格 (SL) 异质结构的光学特性，光子能量为 0.75 至 1.55 eV (NIR-SE)，波数为 250 至 700 cm−1 (IR-SE)。未掺杂的SL结构通过金属有机气相外延（MOVPE）生长在未掺杂的GaAs缓冲层的顶部，该缓冲层沉积在Te掺杂的（001）GaAs衬底上。 InAs 序列由单个单层组成。通过高分辨率透射电子显微镜和高分辨率 X 射线衍射研究研究了样品的结构、成分、层厚度以及平行和垂直晶格失配。我们采用 Adachi 的临界点复合模型进行近带隙光谱区域 (NIR-SE) 的数据分析。为了分析 IR-SE 数据，我们使用谐振子介电函数模型和自由载流子响应的 Drude 模型。我们报告了直接带隙能量 E0，以及 c...
Spectroscopic ellipsometry (SE) is employed to study the optical properties of compressively strained short-period GaAs/InAs/GaNxAs1−x (0%<x<2.4%) superlattice (SL) heterostructures for photon energies from 0.75 to 1.55 eV (NIR-SE), and for wave numbers from 250 to 700 cm−1 (IR-SE). The undoped SL structures were grown on top of undoped GaAs buffer layers deposited on Te-doped (001) GaAs substrates by metalorganic vapor phase epitaxy (MOVPE). The InAs sequences consist of single monolayers. Structure, composition, layer thicknesses, and parallel and perpendicular lattice mismatch of the samples are studied by high-resolution transmission electron microscopy and high-resolution x-ray diffraction investigations. We employ Adachi’s critical-point composite model for data analysis in the near-band-gap spectral region (NIR-SE). For analysis of the IR-SE data we use the harmonic oscillator dielectric function model and the Drude model for free-carrier response. We report the direct band-gap energy E0, and the c...