Dresden 2011 – wissenschaftliches Programm
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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 Feneberg1,2, 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.