Optical properties of AlxGa1-xN/GaN heterostructures on sapphire by spectroscopic ellipsometry

被引：66

作者：

Yu, G

Ishikawa, H

Umeno, M

Egawa, T

Watanabe, J

Jimbo, T

Soga, T

机构：

[1] Nagoya Inst Technol, Res Ctr Microstruct Devices, Showa Ku, Nagoya, Aichi 466, Japan

[2] Nagoya Inst Technol, Dept Elect & Comp Engn, Showa Ku, Nagoya, Aichi 466, Japan

[3] Nagoya Inst Technol, Dept Environm Technol & Urbane Planning, Showa Ku, Nagoya, Aichi 466, Japan

来源：

APPLIED PHYSICS LETTERS | 1998年 / 72卷 / 18期

关键词：

D O I：

10.1063/1.121322

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

A method of analysis of spectroscopic ellipsometry (SE) measurement data is proposed for AlxGa1-xN/GaN heterostructures grown on sapphire substrates. The SE data measured at three angles of incidence, 40 degrees, 50 degrees, and 60 degrees, are simultaneously fitted assuming the dielectric function to consist of a Sellmeir dispersion equation and a free-exciton absorption term. The refractive index n and the extinction coefficient k of undoped AlxGa1-xN films are determined in the spectral range of 1.5-4.13 eV of photon energy. The transition energy of the free exciton, which is in excellent agreement with the reported results for GaN in a previous paper, is found to vary from 3.44 to 3.95 eV when the composition x varies from 0 to 0.151. The refractive index rr of AlxGa1-xN has also been compared with those reported results. (C) 1998 American Institute of Physics.

引用

页码：2202 / 2204

页数：3

共 11 条

[1] ROOM-TEMPERATURE LOW-THRESHOLD SURFACE-STIMULATED EMISSION BY OPTICAL-PUMPING FROM AL0.1GA0.9N/GAN DOUBLE-HETEROSTRUCTURE [J].