V-shaped defects in InGaN/GaN multiquantum wells

被引：60

作者：

Mahanty, S

Hao, M

Sugahara, T

Fareed, RSQ

Morishima, Y

Naoi, Y

Wang, T

Sakai, S

机构：

[1] Univ Tokushima, Dept Elect & Elect Engn, Tokushima 7708506, Japan

[2] Univ Tokushima, Satellite Venture Business Lab, Tokushima 7708506, Japan

来源：

MATERIALS LETTERS | 1999年 / 41卷 / 02期

关键词：

InGaN; GaN; multiquantum well; dislocation; surface defects;

D O I：

10.1016/S0167-577X(99)00105-6

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

InGaN/GaN multiquantum well (MQW) structures have been grown on (0001) sapphire substrate by metalorganic chemical vapor deposition. From cross-sectional transmission electron microscopy (TEM), a number of V-shaped defects has been observed on the surface which are associated with mixed or pure-edge screw dislocations, as well as with inversion domains. Atomic force microscopy (AFM) reveals that these are hexagonal pits with a width of about 70 nm. The mechanism of formation of these defects has been discussed in terms of stress induced by lattice mismatch and reduced In incorporation on the (10 (1) over bar 1) planes in comparison to the (0001) surface. A decrease in In concentration and also in well thickness during growth has been found. No optical emission has been observed from these defects by cathodoluminescence (CL) studies. (C) 1999 Elsevier Science B.V. All rights reserved.

引用

页码：67 / 71

页数：5

共 12 条

[1] Luminescences from localized states in InGaN epilayers [J].