Luminescence of a GaN grain with a nonpolar and semipolar plane in relation to microstructural characterization

• Published in: Chinese physics B 2012-06, Vol.21 (6), p.520-524
• Main Author: 周小伟 许晟瑞 张进成 党纪源 吕玲 郝跃 郭立新
• Format: Article
• Language: English
• Subjects: Crystal defects; Gallium nitrides; GaN; Grains; Interlayers; Luminescence; Planes; Rectangles; Scanning electron microscopy; Threading dislocations; 半极性; 微观结构表征; 扫描电子显微镜; 选择性生长; 透射电子显微镜; 阴极发光; 非极性
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/21/6/067803

We report on the growth of the high-quality GaN grain on a r-plane sapphire substrate by using a self-organized SiN interlayer as a selective growth mask. Transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy are used to reveal the effect of SiN on the overgrown a-plane GaN growth. The SiN layer effectively terminates the propagation of the threading dislocation and basal plane stacking faults during a-plane GaN regrowth through the interlayer, resulting in the window region shrinking from a rectangle to a ＂black hole＂. Furthermore, strong yellow luminescence （YL） in the nonpolar plane and very weak YL in the semipolar plane on the GaN grain is revealed by cathodoluminescence, suggesting that C-involved defects are responsible for the YL.