Influence of MOVPE growth temperature on the structural and optical properties of InGaN MQW laser diodes

V. Hoffmann^a, A. Knauer^a, F. Brunner^a, C. Netzel^a, U. Zeimer^a, S. Einfeldt^a, M. Weyers^a, G. Tränkle^a, J.M. Karaliunas^b, K. Kazlauskas^b, S. Jursenas^b, U. Jahn^c, J.R. van Look^d and M. Kneissl^a,d

^a Ferdinand-Braun-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
^b Institute of Materials Science and Applied Research, Vilnius University, LT-10222 Vilnius, Lithuania
^c Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany
^d Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany

Published in:
Journal of Crystal Growth 310 21 (2008) 4525-4530.
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Abstract:
The morphological and optical properties of InGaN multiple quantum wells (MQWs) emitting at 405 nm are studied with respect to the MQW growth temperature. The latter was varied between 760 and 840 °C in structures grown on c-plane sapphire substrates by metal-organic vapor-phase epitaxy (MOVPE). The indium content in the quantum well was kept constant for all temperatures by adjusting the trimethylindium supply. The MQWs were inserted as active region in both optically pumped laser heterostructures and laser diodes (LDs). We found that low growth temperatures result in a reduced spatial uniformity of the luminescence emission wavelength due to well thickness variations, whereas at higher temperatures it is difficult to obtain a spatially homogeneous indium concentration. A minimum threshold power density for optically pumped lasing was found for growth temperatures of the active region between 780 and 820 °C. LDs with an MQW grown at these conditions showed an onset of lasing at a current density of 6.5 kA/cm² with output powers of more than 350 mW.

Keywords:
A1. Characterization; A1. Interfaces; A3. Metalorganic vapor phase epitaxy; B1. Nitrides; B2. Semiconducting III-V materials; B3. Laser diodes

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