In-situ observation of InGaN quantum well decomposition during growth of laser diodes
V. Hoffmann1, A. Mogilatenko1,2, U. Zeimer1, S. Einfeldt1, M. Weyers1, and M. Kneissl1,3
Published in:
Cryst. Res. Technol., vol. 50, no. 6, pp. 499-503 (2015).
Abstract:
The deterioration of the InGaN active region of laser diode structures emitting around 440 nm is observed in-situ during epitaxial growth and analyzed ex-situ by cathodoluminescence spectroscopy and transmission electron microscopy. The growth conditions of the p-layers on top of the InGaN active region are found to affect the homogeneity of the InGaN material properties which can be monitored by the in-situ reflectance signal at 950 nm. The deposition of the p-layers at 950°C results in the formation of metallic indium platelets as well as voids changing the refractive index of the active region and thus the reflectance. A reduction of the p-layer deposition temperature by 30°C prevents this undesirable decomposition.
1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
2 Humboldt-Universität zu Berlin, Institut für Physik, Berlin, Germany
3 Institut für Festkörperphysik, Technische Universität Berlin, Berlin, Germany
Keywords:
InGaN; quantum wells; nitrides; decomposition
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