Dielectric function and optical properties of quaternary AlInGaN alloys
Dielectric function and optical properties of quaternary AlInGaN alloys
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DOI：
10.1063/1.3603015
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发表时间：
2011-07
影响因子：
3.2
通讯作者：
E. Sakalauskas;B. Reuters;L. Khoshroo;H. Kalisch;M. Heuken;A. Vescan;M. Röppischer;C. Cobet;G. Gobsch;R. Goldhahn
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文献类型：
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作者：
E. Sakalauskas;B. Reuters;L. Khoshroo;H. Kalisch;M. Heuken;A. Vescan;M. Röppischer;C. Cobet;G. Gobsch;R. Goldhahn
本文报道了四元AlxInyGa_（1-x-yN）合金薄膜（0.16< x<0.64，0.02< y<0.13）的光学性质。在厚GaN/蓝宝石模板上用金属有机物气相外延法生长了（0001）取向的AlInGaN层。高分辨率的X射线衍射测量揭示了GaN缓冲层上的AlInGaN薄膜的假晶生长。卢瑟福背散射和波长色散X-射线光谱分析，以确定合金的组成。在室温下通过光谱椭圆偏振法（SE）（同步辐射：BESSY II）在1-10 eV的范围内确定AlInGaN样品的普通介电函数（DF）。DF的虚部的尖锐开始定义了合金的直接吸收边。在较高的光子能量下，在DF中观察到明显的峰，表明材料的有希望的光学质量。这些特征与能带结构的临界点（货车霍韦奇异性）相关。分析师...
The optical properties of quaternary Alx Iny Ga1-x-yN alloy films with 0.16< x<0.64 and 0.02< y<0.13 are presented. The (0001)-oriented AlInGaN layers were grown by metal-organic vapor phase epitaxy on thick GaN/sapphire templates. High-resolution x-ray diffraction measurements revealed the pseudomorphic growth of the AlInGaN films on the GaN buffer. Rutherford backscattering and wavelength-dispersive x-ray spectroscopy analysis were used in order to determine the composition of the alloys. The ordinary dielectric function (DF) of the AlInGaN samples was determined in the range of 1–10 eV by spectroscopic ellipsometry (SE) at room temperature (synchrotron radiation: BESSY II). The sharp onset of the imaginary part of the DF defines the direct absorption edge of the alloys. At higher photon energies, pronounced peaks are observed in the DF indicating a promising optical quality of the material. These features are correlated to the critical points of the band structure (van Hove singularities). An analytica...