Optical and structural characterization of AlInN layers for optoelectronic applications
Optical and structural characterization of AlInN layers for optoelectronic applications
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DOI：
10.1063/1.3467964
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发表时间：
2010-09-15
影响因子：
3.2
通讯作者：
Hommel, D.
中科院分区：
文献类型：
--
作者：
Aschenbrenner, T.;Dartsch, H.;Hommel, D.
采用金属有机物气相外延法生长了铟含量在x=10.5%和x=24%之间的Al（1-x）In（x）N薄膜，并对其光学、结构和形貌特性进行了表征，以实现光电器件。通过高分辨率X射线衍射测量这些层的铟含量和应变。椭圆偏振测量用于确定依赖于波长和铟含量的光学常数[折射率n（λ）和消光系数κ（λ）]。确定的电子带隙的值是在很好的协议与理论预测和以前的出版物在这个话题上，但更专注于AlInN层的GaN上的赝晶生长。对于铟含量在13%和24%之间的完全应变层，确定弯曲参数为B=10.3 +/- 0.1。为了研究这些层用于分布式布拉格反射器的适用性，表面形态的特征在于相对于铟含量。此外，退火步骤，这往往是必要的，在器件生长过程中的影响，进行了研究。通过原子力显微镜分析了退火步骤对粗糙度的影响，同时通过高分辨率二次电子显微镜图像监测结构特征。基于这些结果的分布布拉格反射器的绿色光谱区域与高达40对和峰值反射率为97%已实现。层界面的透射电子显微镜分析与单层表面的原子力和二次电子显微镜图像吻合良好。(C)2010年美国物理学会。[doi：10.1063/1.3467964]
Al(1-x)In(x)N layers with an indium content between x=10.5% and x=24% were grown by metal-organic vapor-phase epitaxy and characterized concerning their optical, structural and morphological properties with regard to the realization of optoelectronic devices. The indium content and the strain of these layers were measured by high resolution x-ray diffraction. Ellipsometric measurements were used to determine the optical constants [refractive index n(lambda) and extinction coefficient kappa(lambda)] in dependence of wavelength and indium content. The values determined for the electronic bandgaps are in good agreement with theoretical predictions and previous publications on this topic but are more focused on AlInN layers which are pseudomorphically grown on GaN. A bowing parameter of b=10.3 +/- 0.1 was determined for fully strained layers with an indium content between 13% and 24%. In order to investigate the suitability of these layers for use in distributed Bragg reflectors, the surface morphology is characterized with respect to the indium content. Furthermore, the influence of an annealing step which often is necessary during device growth, was studied. The influence of this annealing step on the roughness was analyzed by atomic force microscopy, while structural features are monitored by high resolution secondary electron microscopy images. Based on these results distributed Bragg reflectors for the green spectral region with up to 40 pairs and a peak reflectivity of 97% have been realized. Transmission electron microscopic analysis of the layer interfaces are in good agreement with the atomic force and secondary electron microscopy images of the single layer surfaces. (C) 2010 American Institute of Physics. [doi:10.1063/1.3467964]