Characteristics of high Al content AlGaN grown by pulsed atomic layer epitaxy

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• 作者：Xu Pan^a ; ^{xpan@semi.ac.cn"" rel=""nofollow} ; Xiaoliang Wang^a ; ^b ; Hongling Xiao^a ; ^b ; Cuimei Wang^a ; ^b ; Cuibai Yang^a ; ^b ; Wei Li^b ; Weiying Wang^b ; Peng Jin^b ; Zhanguo Wang^a ; ^b
• 关键词：Photoluminescence ; Raman scattering ; Pulsed atomic layer epitaxy ; AlGaN alloys
• 刊名：Applied Surface Science
• 出版年：2011
• 出版时间：1 August 2011
• 年：2011
• 卷：257
• 期：20
• 页码：8718-8721
• 全文大小：549 K

文摘

Al_0.91Ga_0.09N epilayers have been obtained by pulsed atomic layer epitaxy (PALE) technique on sapphire (0 0 0 1) substrates. Deep ultraviolet (DUV) photoluminescence (PL) spectroscopy and Raman scattering spectrum have been employed to study the optical transitions in Al_0.91Ga_0.09N epilayers. We found the exciton-phonon interaction by fitting the asymmetric PL peak, in which the transverse optical phonon (TO) and the longitudinal optical (LO) phonon are the main contributor. The abnormal S-shaped temperature dependence of the PL band peak is less pronounced or has disappeared. Further analysis shows that there possibly exists a high density of deeper localized state (90 meV) in Al_0.91Ga_0.09N. The formation of these localized states provides a favorable condition for efficient light emission.