Characterization of InGaN/GaN multiple quantum wells grown on sapphire substrates by nano-scale epitaxial lateral overgrowth technique

W. K. Fong, K. K. Leung, Charles Surya

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

High-quality InGaN/GaN multiple quantum wells (MQWs) were fabricated on nanoscale epitaxial lateral overgrown (NELO) GaN layers which was prepared using nanometer-scale SiO 2 islands, with an average diameter and interdistance of 300nm and 200nm respectively, as the growth mask. The active region of the device consists of five periods of GaN/InGaN MQWs were grown on top of the NELO layer using MOCVD technique. It is observed that some of the dislocations from the undoped GaN were blocked by the SiO 2 growth mask and typical threading dislocation (TD) density found in the NELO samples is ∼7.5×10 7cm -2. Significant improvement in the electroluminescence (EL) is observed which is believed to partly arise from the improvement in the internal quantum efficiency (η i). The experimental data on the temperature dependence of the photoluminescence (PL) were fitted to a proposed model using Levenberg-Marquardt approximation. Based on our analyses it is found that the relative improvement in η i at 300K over a control device grown in the same growth condition but without the NELO layer to a NELO device is only 0.59. It is generally accepted that TD is the non-radiative recombination center which affects the IQE. Therefore, room-temperature IQE values also support that NELO device exhibits lower TD density.

Original languageEnglish
Title of host publicationNovel Fabrication Methods for Electronic Devices
Pages1-5
Number of pages5
Volume1288
DOIs
Publication statusPublished - Dec 1 2011
Externally publishedYes
Event2010 MRS Fall Meeting - Boston, MA, United States
Duration: Nov 29 2010Dec 3 2010

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1288
ISSN (Print)0272-9172

Conference

Conference2010 MRS Fall Meeting
CountryUnited States
CityBoston, MA
Period11/29/1012/3/10

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

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