Yellow luminescence from precipitates in GaN epilayers

被引：0

作者：

J. Kang

T. Ogawa

机构：

[1] Department of Physics,

[2] Xiamen University,undefined

[3] Xiamen 361005,undefined

[4] P.R. China (Fax: +86-592/2033-025),undefined

[5] Department of Physics,undefined

[6] Gakushuin University,undefined

[7] Mejiro,undefined

[8] Tokyo 171,undefined

[9] Japan (Fax: +81-3/3590-2602),undefined

来源：

Applied Physics A | 1999年 / 69卷

关键词：

PACS: 78.60H; 68.55.L; 61.16.B; 81.30.M; 81.70.J;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

The room-temperature photoluminescence spectra of GaN epilayers with different surface morphologies grown by metalorganic vapor phase epitaxy exhibited a near-band-gap emission peak and a broad emission band in the yellow region. The intensity distributions of the yellow luminescence observed by cathodoluminescence (CL) were characterized by a number of dark and bright tortuous regions in sample A with a specular surface and by many bright hexagrams in sample B with a hexagonal hillock surface. Instead of the CL bright hexagrams, a number of CL bright line segments parallel to <112_0> directions were visible in sample B after the epilayer surface hillocks were polished. GaN epilayer images by high-resolution transmission electron microscopy exhibited a number of circular or hexagonal defects in sample A and many longer defects arranged in <112_0> directions in sample B. The compositions of the defects in these images were analyzed by energy-dispersive X-ray spectrometry and found to be composed of carbon, oxygen, and gallium elements. The results suggest that the C- and O-related defects are responsible for the yellow luminescence from the precipitates in imperfect coalescence.

引用

页码：631 / 635

页数：4