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HL: Fachverband Halbleiterphysik
HL 7: III-V semiconductors I
HL 7.2: Talk
Monday, March 26, 2007, 11:15–11:30, H17
Optical Spectroscopy of doped and undoped Aluminium Nitride Layers on Sapphire Substrates — •Günther M. Prinz1, Martin Schirra1, Martin Feneberg1, Sarad B. Thapa2, Matthias Bickermann3, Boris Epelbaum3, Ferdinand Scholz2, Rolf Sauer1, and Klaus Thonke1 — 1Institut für Halbleiterphysik, Universität Ulm, D-89069 Ulm — 2Institut für Optoelektronik, Universität Ulm, D-89069 Ulm — 3Institut für Werkstoffwissenschaften 6, Universität Erlangen, D-91058
Doped and undoped aluminium nitride layers were grown by MOVPE on sapphire substrates. We investigate these layers by photoluminescence, cathodoluminescence, and reflectance spectroscopy, and determine the fundamental band gap energy and the crystal field splitting of aluminium nitride. The temperature dependence of the near-band edge luminescence is investigated from 10K to 300K.
Doped and undoped samples are differently strained. Strain is tensile as measured by red-shifts of the near-band edge luminescence. Tensile strain is also observed by Raman measurements which show a shift of the E2 mode to lower wave numbers. Based on these measurements we use appropriate deformation potentials to quantitatively calculate the strain in the aluminium nitride layers.