Performance Characteristics of UV-C AlGaN-Based Lasers Grown on Sapphire and Bulk AlN Substrates
M. Martens1, F. Mehnke1, C. Kuhn1, C. Reich1, V. Kueller2, A. Knauer2, C. Netzel2, C. Hartmann3, J. Wollweber3, J. Rass1, T. Wernicke1, M. Bickermann3, M. Weyers2, and M. Kneissl1,2
Published in:
IEEE Photonics Technol. Lett., vol. 26, no. 4, pp. 342-345 (2014).
Abstract:
The performance characteristics of optically pumped laser heterostructures emitting in the UV-C spectral range between 272 and 279nm are investigated. The laser heterostructures were grown by metal-organic vapor phase epitaxy on (0001) planar AlN/sapphire, epitaxially laterally overgrown (ELO) AlN/sapphire, and bulk AlN substrates with threading dislocation densities ranging from 2×1010 to 104 cm-2. We found that the defect density strongly affects the laser performance. The lowest pulse threshold energy density of 50 mJ/cm2 under resonant optical pumping condition was obtained for an AlGaN multiple quantum well laser grown pseudomorphically on low defect density bulk AlN substrate. Lasing was also observed for AlGaN MQW heterostructures grown on ELO AlN/sapphire templates. The laser emission in all lasers was TE polarized. However, no lasing was observed for heterostructures grown on high defect density AlN/sapphire.
1 Institut für Festkörperphysik, Technische Universität Berlin, Berlin 10623, Germany
2 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
3 Leibniz-Institut für Kristallzüchtung, Berlin 12489, Germany
3 Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
Index Terms:
AlGaN, AlN substrates, epitaxial lateral overgrowth, lasers, polarization, sapphire substrates, ultraviolet.
© Copyright 2014 IEEE - All Rights Reserved. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Full version in pdf-format.