Alloy fluctuations at dislocations in III-nitrides: dentification and impact on optical properties

F. C.-P. Massabuau, P. Chen, S. L. Rhode, M. K. Horton, T. J. O'Hanlon, A. Kovács, M. S. Zielinski, M. J. Kappers, R. E. Dunin-Borkowski, C. J. Humphreys, R. A. Oliver

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We investigated alloy fluctuations at dislocations in III-Nitride alloys (InGaN and AlGaN). We found that in both alloys, atom segregation (In segregation in InGaN and Ga segregation in AlGaN) occurs in the tensile part of dislocations with an edge component. In InGaN, In atom segregation leads to an enhanced formation of In-N chains and atomic condensates which act as carrier localization centers. This feature results in a bright spot at the position of the dislocation in the CL images, suggesting that non-radiative recombination at dislocations is impaired. On the other hand, Ga atom segregation at dislocations in AlGaN does not seem to noticeably affect the intensity recorded by CL at the dislocation. This study sheds light on why InGaN-based devices are more resilient to dislocations than AlGaN-based devices. An interesting approach to hinder non-radiative recombination at dislocations may therefore be to dope AlGaN with In.
Original languageEnglish
Title of host publicationProceedings Volume 10532, Gallium Nitride Materials and Devices XIII
Place of PublicationBellingham, Washington
Number of pages6
Publication statusPublished - 23 Feb 2018
EventSPIE Optics + Photonics 2018 - San Diego Convention Center, San Diego, United States
Duration: 21 Aug 201823 Aug 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceSPIE Optics + Photonics 2018
Abbreviated titleSPIE OPTO 2018
Country/TerritoryUnited States
CitySan Diego
Internet address


  • dislocation
  • III-Nitrides
  • segregation
  • carrier localization
  • aberration-corrected TEM
  • cathodoluminescence


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