Effect of GaN cap thickness on carrier dynamics in InGaN quantum wells

Oleksii Kopylov, Roza Shirazi, O. Svensk, S. Suihkonen, S. Sintonen, M. Sopanen, Beata Kardynal

Research output: Contribution to journalConference articleResearchpeer-review

Abstract

We have studied optical properties of single In0.1Ga0.9N quantum wells with GaN barriers in close proximity to the wafer surface (<10 nm). We have found that at room temperature a balance of radiative, non-radiative recombination and complex surface states effects results in an optimum cap thickness of 3nm for achieving highest brightness emitters. At low temperature, we observe a behaviour that suggests that some surface states act as trapping centres for carriers rather than as a non-radiative recombination channel. Temperature dependence of the photoluminescence decay curves shows that carrier lifetimes in all the wafers increase at lower temperatures and reach similar maximum value. Main features of the evolution of lifetimes with temperature can be explained satisfactory by a combination of radiative, non-radiative recombination and above mentioned twofold surface effects. Detailed picture of the carrier dynamics is however complex and needs to include the modification of the electrostatic potential in the quantum wells positioned in the surface depletion regions.
Original languageEnglish
JournalPhysica Status Solidi. C: Current Topics in Solid State Physics
Volume9
Issue number3‐4
Pages (from-to)727-729
ISSN1862-6351
DOIs
Publication statusPublished - 2012
Event9th International Conference on Nitride Semiconductors (ICNS) - Glasgow, United Kingdom
Duration: 10 Jul 201115 Jul 2011

Conference

Conference9th International Conference on Nitride Semiconductors (ICNS)
CountryUnited Kingdom
CityGlasgow
Period10/07/201115/07/2011

Keywords

  • Gallium nitride
  • Recombination
  • Photoluminescence
  • Time-resolved photoluminescence
  • Surface states
  • Localisation

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