Aging Mechanisms of InGaN/AlGaN/GaN Light-Emitting Diodes Operating at High Currents


F. Manyakhin, A. Kovalev
Moscow Institute of Steel and Alloys

A. E. Yunovich
M.V.Lomonosov Moscow State University

This article was received on Thursday, July 23, 1998 and accepted on Tuesday, December 15, 1998.

Abstract

Changes of luminescence spectra and electrical properties of light-emitting diodes (LED's) based on InGaN/AlGaN/GaN heterostructures were investigated over a long period of operation. Blue and green LED's with InGaN single quantum wells were studied at currents up to 80 mA for 102-2.103 hours. An increase of luminescence intensity at operating currents of 15 mA was detected at the 1st stage of aging (100-800 hours) and a slow fall was detected in the 2nd stage. Greater changes of spectra were observed at low currents (< 0.15 mA). A study of charged acceptor distribution in the space charge region has shown that at the 1st stage their concentration grows, and in the 2nd stage, it falls. The models for the two stages are proposed: 1) activation of Mg due to destruction of residual Mg-H complexes; 2) formation of donor vacancies N. A model of defect formation by hot electrons injected into the quantum well is discussed.

Outline

  • Introduction
  • Experimental
  • Experimental results.
  • Changes of electroluminescence spectra.
  • Changes of electrical properties.
  • Discussion
  • Model of growth and fall of the luminescence efficiency.
  • Formation of sub-threshold defects by electron injection.
  • Analysis of the sub-threshold defect formation.
  • Probability of atom displacement by hot electrons.
  • Distribution of created defects versus time and distance.
  • Conclusions
  • Acknowledgments

    • Linked Pages

    Cite this article as: MRS Internet J. Nitride Semicond. Res. 3, 53(1998).

    last updated Saturday, December 19, 1998 3:09:30 PM.

    © 1998 The Materials Research Society MRS Internet Journal of Nitride Semiconductor Research
    ISBN links