An X-ray diffraction and Raman spectroscopy investigation of AlGaN epi-layers with high Al composition

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• 作者：Shuchang Wang^a ; ^b ; ^{scw@cslg.edu.cn} ; Xiong Zhang^b ; Qian Dai^b ; Zhe Chuan Feng^c ; Yiping Cui^b
• 关键词：AlGaN ; Metalorganic chemical vapor deposition ; Crystalline quality ; Optical property ; Raman spectroscopy
• 刊名：Optik - International Journal for Light and Electron Optics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：131
• 期：Complete
• 页码：201-206
• 全文大小：1354 K
• 卷排序：131

文摘

The AlxGa1-xN (0.15 ≤ x ≤ 0.87) epi-layers were grown on c-plane sapphire substrate by metal organic chemical vapor deposition (MOCVD). Based on a combination of X-ray diffraction, optical transmission and Raman spectra experiments, it is shown that the structural and optical properties of AlxGa1-xN epi-layers are governed by the presence of compositional fluctuations associated with strongly localized electronic states. The asymmetric behavior of the Raman E2 mode of AlxGa1-xN epi-layers was attributed to the activation of phonons arising from the disordered state of the alloys. Hydrostatic pressure increases the splitting of A1GaN phonons mode especially for AlGaN epi-layer with high Al composition.