Paper Title:
The Morphology and Optical Characterizations of AlGaN/GaN Based on Al2O3 Prepared by MOCVD
  Abstract

The microstructure, optical absorption properties and luminescence function of GaN thin films grown on the sapphire substrate with the buffer layer of GaN by metal-organic chemical vapor deposition (MOCVD) have been studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared transmission spectrum, ultraviolet-visible absorption spectrum and photoluminescence. XRD results show that the crystal structure of GaN is hexagonal wurtzite structure. The thin films have preferred orientation in c axis with very high quality. TEM images of the cross-sectional specimen show that the thickness of every layer in the superlattice are uniform with the average period of 13.3 nm, but there are high-density dislocations in the superlattices region. From related optical experimental data, it is found that optical absorption edge is at about 370 nm. The theory calculation indicates that the five samples are direct transition semiconductor and band-gaps are about 3.4 eV. The refractive indexes of the samples increase with photon energy enhancing and decrease with the wavelength increasing. The results show that the extinction coefficients reach the lowest point at 370 nm. Photoluminescence test results show that superlattice has preferable luminescence property. In addition, the yellow luminescence is found in all samples.

  Info
Periodical
Materials Science Forum (Volumes 475-479)
Main Theme
Edited by
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
Pages
3713-3716
DOI
10.4028/www.scientific.net/MSF.475-479.3713
Citation
M.C. Li, L. C. Zhao, H.M. Li, "The Morphology and Optical Characterizations of AlGaN/GaN Based on Al2O3 Prepared by MOCVD", Materials Science Forum, Vols. 475-479, pp. 3713-3716, 2005
Online since
January 2005
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Hui Liao, Wei Hua Chen, Fen Fen Wei, Juan Hou
Abstract:AlGaN/GaN superlattice are the important structure of optoelectronic devices such as light-emitting diodes and laser diodes. The...
879
Authors: Lian Jia Wang, You Zhang Zhu, Hong Xia Wang, Ben Li Liu, Jin She Yuan
Abstract:Recent achievements in III-nitride semiconductor structures growth have allowed ultraviolet (UV) photo-detectors based on these compounds to...
966
Authors: Chwan Ying Lee, Yung Hsiang Chen, Lurng Shehng Lee, Chien Chung Hung, Cheng Tyng Yen, Suh Fang Lin, Rong Xuan, Wei Hung Kuo, Tzu Kun Ku, Ming Jinn Tsai
Chapter 7: Related Materials
Abstract:One normally-on N-channel AlGaN/GaN device and two types of normally-off GaN devices have been studied. The normally-on device with Sapphire...
1303
Authors: Jun Feng Chen
Chapter 1: Chemical Engineering
Abstract:Although the research of bulk GaN material has take great progress in recent years, while the high quality of p-type GaN material still is an...
274