Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 56: Non- and Semi-polar Group-III-Nitrides
HL 56.1: Vortrag
Donnerstag, 25. März 2010, 14:00–14:15, H15
Optical anisotropy of a- and m-plane InN grown on free-standing GaN substrates — •Jochen Räthel1, Pascal Schley1, Egidius Sakalauskas1, Gerhard Gobsch1, René Müller1, Thomas A. Klar1, Jörg Pezoldt1, Rüdiger Goldhahn1, Gregor Koblmüller2,3, James S. Speck2, Matthias Wieneke4, Jürgen Bläsing4, and Alois Krost4 — 1Institut für Physik, Technische Universität Ilmenau — 2Materials Department, University of California — 3Walter Schottky Institut, Technische Universität München — 4Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg
The optical response of wurtzite nitride semiconductors at the band gap and in the spectral region of high-energy critical points differs appreciably for light polarization perpendicular (ordinary configuration) and parallel (extraordinary) to the c-axis. In order to demonstrate this effect, films (or bulk crystals) are required for which the optical axis lies in the surface plane (a- or m-plane). For InN, the only studies reported so far employed an a-plane layer deposited on r-plane sapphire with an a-plane GaN buffer. Considerable improvement of the film quality was recently achieved by growing a- and m-plane InN directly on free-standing a- and m-plane GaN by PAMBE. In this contribution, we present a comprehensive characterization of these higher-quality non-polar InN materials by polarization-dependent Raman spectroscopy and ellipsometry. The influence of stress on the transition energies is discussed based on the lattice parameters obtained by high-resolution XRD.