Berlin 2005 – scientific programme

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HL: Halbleiterphysik

HL 17: Poster Ib

HL 17.52: Poster

Friday, March 4, 2005, 16:30–19:00, Poster TU F

Magneto-optical spectroscopy and thermal annealing effects in GaInNAs / GaAs quantum well structures and bulk GaAsN — •A. Grau, P. Feinäugle, W. Löffler, H. Kalt, and M. Hetterich — Institut für Angewandte Physik and Center for Functional Nanostructures (CFN), Universität Karlsruhe, D - 76131 Karlsruhe, Germany

As a promising material system for the realization of near infrared optoelectronic devices GaInNAs / GaAs gained more and more importance, but still many material parameters are not well known.

In earlier investigations we used photoreflectance (PR) and photoluminescence excitation (PLE) spectroscopy in order to get more information about the band alignment and conduction band dispersion in GaInNAs-based quantum well structures as a function of compositions and well width. In this contribution we present the results of extended studies using magneto-photoluminescence (MPL) and magneto-absorption of GaInNAs / GaAs multiple quantum well structures. From the theoretical modelling of our MPL measurements we are able to obtain values for the reduced effective exciton mass and the electron effective mass. As expected a strong increase in the electron effective mass due to the presence of nitrogen is found, in good agreement with theory and our earlier PLE and PR results.

Additionally, we studied the effect of thermal annealing on the photoluminescence (PL) of GaAsN bulk samples in terms of intensity, line width and energy shift of the PL peak.