Role of Dislocation in InGaN/GaN Quantum Wells Grown on Bulk GaN and Sapphire Substrates

  • SUGAHARA Tomoya
    Department of Electrical and Electronic Engineering, University of Tokushima
  • SAKAI Shiro
    Department of Electrical and Electronic Engineering, University of Tokushima

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Abstract

Dislocation properties in InGaN/GaN Quantum Wells and GaN grown on bulk GaN and sapphire substrates by metalorganic chemical vapor deposition (MOCVD) were characterized using cathodoluminescnece (CL), transmission electron microscopy (TEM), atomic force microscopy (AFM) and photoluminescence (PL). It was clearly demonstrated that dislocations act as nonradiative recombination centers in both n-type (undoped and Si-doped) GaN and InGaN layers. Furthermore the very short-minority carrier diffusion length was a key parameter to explain the high light emission efficiency in GaN-based light emitting diodes (LEDs) prepared on sapphire substrates. On the other side band-tail states were detected in the heteroepitaxial InGaN layers only by temperature dependence PL measurement. Additionally InGaN phase separation, which consists of few micron domains, has been produced under growth conditions which favors the spiral growth. These results indicate that the dislocations in the InGaN layers act as triggering centers for the InGaN phase separation which cause both a compositional fluctuation and the formation of few micron phase separated domains. The homoepitaxial InGaN layers showed however quite normal behaviors for all characterizations.

Journal

  • IEICE transactions on electronics

    IEICE transactions on electronics 83 (4), 598-604, 2000-04-25

    The Institute of Electronics, Information and Communication Engineers

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Details 詳細情報について

  • CRID
    1572543027349091968
  • NII Article ID
    110003211877
  • NII Book ID
    AA10826283
  • ISSN
    09168524
  • Text Lang
    en
  • Data Source
    • CiNii Articles

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