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HL: Fachverband Halbleiterphysik

HL 34: Poster I: III-V Semiconductors

HL 34.35: Poster

Dienstag, 23. März 2010, 18:30–20:30, Poster D2

Optical gain studies of green emitting GaInN based laser structures — •Moritz Brendel, Alexander Daniel Dräger, Holger Jönen, Uwe Rossow, and Andreas Hangleiter — Institut für Angewandte Physik, TU Braunschweig, Germany

Violet-blue emitting laser diodes based on GaInN with high output powers and long lifetimes are now commercially available. Recently, structures based on the same material system emitting in the green spectral range were obtained [1]. The aim of this work is to systematically investigate and characterize the parameters of c-plane GaInN single quantum well laser structures grown by MOVPE on c-plane sapphire substrates. For tuning the wavelength beyond 500 nm we increase the indium concentration of the active region far above 30% and by utilizing thin quantum wells of about 1.5 nm the evoking influence of the piezoelectric fields is reduced. We perform optical gain measurements using the variable stripe length technique to determine the optical gain and losses. Furthermore, by combining the measured data with model calculations of the optical gain spectra we have access to threshold power densities, carrier densities as well as to radiative and nonradiative lifetimes. We find a rather small broadening of the gain spectra but an increasing threshold pump power for longer wavelengths.

[1] Avramescu et al, APL vol95, p071103 (2009)