Regensburg 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 45: Group-III-Nitrides: Optical Properties II
HL 45.10: Talk
Wednesday, March 24, 2010, 17:00–17:15, H15
Optical properties of homoepitaxial AlN — •Martin Feneberg1, Benjamin Neuschl1, Ramon Collazo2, Anthony Rice2, Zlatko Sitar2, Jinqiao Xie3, Seiji Mita3, Georg Rossbach4, Rüdiger Goldhahn4, Marcus Roeppischer5, Christoph Cobet5, Norbert Esser5, and Klaus Thonke1 — 1Institut für Halbleiterphysik, Universität Ulm — 2Dept. of Mat. Sci. Engr., North Carolina State University, USA — 3HexaTech, Inc., Morrisville, NC, USA — 4Institut für Physik, TU Ilmenau — 5ISAS, Berlin
Homoepitaxial c- and m-plane AlN layers, deposited by MOCVD on bulk PVT AlN are investigated by means of high resolution photoluminescence and spetroscopic ellipsometry. We find donor bound exciton lines with a full width at half maximum below 500 µeV at T = 10 K. The exciton binding energy amounts to 52 meV in the c-plane sample leading to a bandgap energy of 6.092 eV (at 10 K). By spectroscopic ellipsometry we access both the ordinary and the extraordinary dielectric functions. The analysis of the sharp free exciton resonance found in the extraordinary tensor components yields a transition energy being in excellent agreement with the emission studies. The ordinary component exhibits a feature which indicates a strong contribution of exciton-phonon interaction to the absorption process.