Misfit dislocations in In-rich InGaN/GaN quantum well structures

P. M F J Costa*, R. Datta, M. J. Kappers, M. E. Vickers, C. J. Humphreys, D. M. Graham, P. Dawson, M. J. Godfrey, E. J. Thrush, J. T. Mullins

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Strain relaxation has been studied for the 10-period quantum well (QW) heterostructures grown by MOVPE, In 0.16Ga 0.84N/GaN and In 0.2Ga 0.8N/GaN, both emitting with high efficiency in the blue and green regions, respectively. Additionally, a set of high-In content InGaN/GaN QW structures, where growth parameters were kept constant but QW numbers varied between 1 and 10, were also analysed by TEM, XRD and PL. For the highly-efficient green and the set of variable QW samples, TEM structural studies identified large well-width fluctuations and misfit dislocations that thread into the sample surface and are generated in the quantum well stack. This contrasts with similar observations of blue-emitting MQWs where misfit dislocations are not seen. PL measurements have been carried out for the In-rich QW series and did not reveal a greater degradation of the optical properties with increasing numbers of quantum wells in the stack.

Original languageEnglish (US)
Pages (from-to)1729-1732
Number of pages4
JournalPhysica Status Solidi (A) Applications and Materials Science
Volume203
Issue number7
DOIs
StatePublished - May 2006
Externally publishedYes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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