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Proceedings Paper

Temperature dependence of blue InGaN lasers
Author(s): Stefanie Brüninghoff; Sönke Tautz; Matthias Sabathil; Désirée Queren; Stephan Lutgen; Uwe Strauß
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Paper Abstract

True blue lasers with wavelengths of ~450 nm are of great interest for full color laser projection. These kind of applications usually require high output power and, in particular, an excellent wall plug efficiency within a wide temperature range. In this paper we therefore present experimental and theoretical investigations of the temperature behavior of 60mW InGaN lasers in a range of -10 °C to 100 °C. The laser parameters threshold current density, slope efficiency and operating voltage describe the wall plug efficiency of the device. The slope efficiency does not show any significant temperature dependence which is due to an almost temperature independent injection efficiency in the temperature range that is of interest for most commercial applications. In contrast, the laser threshold current density increases with temperature and we determine a characteristic temperature T0 of about 141K for our devices emitting at 445nm. This increasing threshold current density can be explained by lower gain of the quantum wells at higher temperature. Furthermore, Auger recombination influences the threshold as verified by simulations. The second electro-optical parameter is the electrical voltage, which is dominated by electrical barriers. The voltage decreases with increasing temperature and compensates the increasing threshold current resulting in a nearly constant high wall plug efficiency of 13% between -10°C and 100°C.

Paper Details

Date Published: 18 February 2009
PDF: 7 pages
Proc. SPIE 7216, Gallium Nitride Materials and Devices IV, 72161C (18 February 2009); doi: 10.1117/12.807979
Show Author Affiliations
Stefanie Brüninghoff, OSRAM Opto Semiconductors GmbH (Germany)
Sönke Tautz, OSRAM Opto Semiconductors GmbH (Germany)
Matthias Sabathil, OSRAM Opto Semiconductors GmbH (Germany)
Désirée Queren, OSRAM Opto Semiconductors GmbH (Germany)
Stephan Lutgen, OSRAM Opto Semiconductors GmbH (Germany)
Uwe Strauß, OSRAM Opto Semiconductors GmbH (Germany)

Published in SPIE Proceedings Vol. 7216:
Gallium Nitride Materials and Devices IV
Hadis Morkoç; Cole W. Litton; Jen-Inn Chyi; Yasushi Nanishi; Joachim Piprek; Euijoon Yoon, Editor(s)

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