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HL: Fachverband Halbleiterphysik

HL 65: Nitrides: AlGaN

HL 65.3: Vortrag

Mittwoch, 16. März 2011, 17:30–17:45, POT 51

Ultraviolet photoluminescence excitation spectroscopy of AlGaN and AlN — •Martin Feneberg^1,2, Benjamin Neuschl², Tobias Meisch², Klaus Thonke², Robert Metzner¹, Bernd Garke¹, and Rüdiger Goldhahn¹ — ¹Abteilung Materialphysik, Otto-von-Guericke-Universität Magdeburg — ²Institut für Quantenmaterie/ Gruppe Halbleiterphysik, Universität Ulm

We present first results of photoluminescence excitation spectroscopy on AlN thin films and high aluminum content AlGaN layers. These studies were performed at the DORIS III synchrotron, DESY, Hamburg. The origin of observed deep emission bands in AlN can be distinguished between substrate and epilayer. In high aluminum content AlGaN, position and shape of the ordinary absorption edge can be observed. These data are compared to the ordinary dielectric function obtained by spectroscopic ellipsometry and to low temperature photoluminescence spectra obtained by ArF excimer laser excitation (λ = 193 nm). We discuss possible origins of so-called "near band-gap" luminescence in AlGaN. Furthermore, the experimental data allows insight into energy positions of semi-core level states in AlGaN, which opens a way to determine the Fermi level energy in these materials.