Bias dependence and correlation of the cathodoluminescence and electron beam induced current from an InGaN/GaN light emitting diode

M. J. Wallace, P. R. Edwards, M. J. Kappers, M. A. Hopkins, F. Oehler, S. Sivaraya, D. W. E. Allsopp, R. A. Oliver, C. J. Humphreys, R. W. Martin

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Abstract

Micron-scale mapping has been employed to study a contacted InGaN/GaN LED using combined electroluminescence (EL), cathodoluminescence (CL), and electron beam induced current (EBIC). Correlations between parameters, such as the EBIC and CL intensity, were studied as a function of applied bias. The CL and EBIC maps reveal small areas, 2–10 μm in size, which have increased nonradiative recombination rate and/or a lower conductivity. The CL emission from these spots is blue shifted, by 30–40 meV. Increasing the reverse bias causes the size of the spots to decrease, due to competition between in-plane diffusion and drift in the growth direction. EL mapping shows large bright areas (∼100 μm) which also have increased EBIC, indicating domains of increased conductivity in the p and/or n-GaN.
Original languageEnglish
Article number033105
Number of pages6
JournalJournal of Applied Physics
Volume116
Issue number3
Early online date18 Jul 2014
DOIs
Publication statusPublished - 2014

Keywords

  • bias dependence
  • cathodoluminescence
  • electron beam induced current
  • InGaN/GaN
  • micron-scale mapping
  • light emitting diode
  • electroluminescence

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