Low temperature photoluminescence and cathodoluminescence studies of nonpolar GaN grown using epitaxial lateral overgrowth
Low temperature photoluminescence and cathodoluminescence studies of nonpolar GaN grown using epitaxial lateral overgrowth
复制标题
使用外延横向过度生长生长的非极性 GaN 的低温光致发光和阴极发光研究
DOI：
10.1063/1.3460641
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发表时间：
2010
影响因子：
3.2
通讯作者：
R. Oliver
中科院分区：
文献类型：
--
作者：
M. Häberlen;T. Badcock;M. Moram;J. Hollander;M. Kappers;P. Dawson;C. Humphreys;R. Oliver
低温阴极和光致发光已进行非极性a面GaN薄膜外延横向过生长。在低V-III比下过度生长的薄膜中，发射光谱以“黄色”和“蓝色”发光带为主，这归因于点缺陷或杂质处的复合。观察到这种发射的强度沿着-c方向在整个窗口区域沿着稳定地降低，这可能是由于点缺陷/杂质物种的不对称扩散。当在较高的V-III比过度生长时，近带边和基面层错发射强度增加了几个数量级，并观察到施主-受主对带。使用单色阴极发光成像，各种发射特征与膜的微观结构相关。特别是，基面层错发射的峰值能量在机翼相对于窗口区域蓝移了约15 meV，这可能与不同的应变速率有关。
Low temperature cathodo- and photoluminescence has been performed on nonpolar a-plane GaN films grown using epitaxial lateral overgrowth. In films overgrown at a low V–III ratio, the emission spectrum is dominated by “yellow” and “blue” luminescence bands, attributed to recombination at point defects or impurities. The intensity of this emission is observed to decrease steadily across the window region along the −c direction, possibly due to asymmetric diffusion of a point defect/impurity species. When overgrown at a higher V–III ratio, the near band edge and basal-plane stacking fault emission intensity increases by orders of magnitude and a donor–acceptor pair band is observed. Using monochromatic cathodoluminescence imaging, the various emission features are correlated with the microstructure of the film. In particular, the peak energy of the basal-plane stacking fault emission is seen to be blueshifted by ∼15 meV in the wing relative to the window region, which may be related to the different strain s...