Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 50: Gallium Nitride: Fabrication and Characterization
HL 50.11: Vortrag
Mittwoch, 9. März 2016, 12:30–12:45, H17
Modulation spectroscopy of semipolar InGaN/GaN light emitting diodes — •Stefan Freytag1, Monir Rychetsky2, Tim Wernicke2, Ingrid Koslow2, Duc V. Dinh3, Brian Corbett3, Peter J. Parbrook3, Martin Feneberg1, Rüdiger Goldhahn1, and Michael Kneissl2 — 1Institut für Experimentelle Physik, Otto-von-Guericke-Universität, Magdeburg, Germany — 2Institut für Festkörperphysik, Technische Universität, Berlin, Germany — 3Tyndall National Institute, University College Cork, Cork, Ireland
Semipolar InGaN/GaN light emitting diodes containing three InGaN quantum well (QWs) were grown on (2021) and (2021) oriented bulk GaN substrates. The indium content of the QWs was varied between 0.13 and 0.24. Modulation spectroscopy measurements at variable temperatures are employed to investigate electro-optic properties of the devices. By photoreflection we observe free excitons in the GaN matrix and find a very prominent signal from the InGaN quantum wells. The energy position as a function of temperature is compared to photoluminescence data. In polarization dependend measurements we clearly observe a shift of the characteristic quantum well transition energy for different polarization angles attributed to the selection rules of the corresponding valence bands. Excitation density dependent photoluminescence and photoreflection measurements support this explanation. The studies contribute to the understanding of the valence band structure and the quantification of the polarization fields in semipolar InGaN/GaN multi quantum well structures.