Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 69: Symposium Polarization Field Control in Group-III-Nitrides
O 69.5: Hauptvortrag
Donnerstag, 25. März 2010, 11:45–12:15, H1
Three-dimensional GaN for semipolar light emitters — •Thomas Wunderer1, Frank Lipski1, Stephan Schwaiger1, Ferdinand Scholz1, Martin Feneberg1, Klaus Thonke1, Andrey Chuvilin1, Ute Kaiser1, Sebastian Metzner2, Frank Bertram2, Jürgen Christen2, Clemens Vierheilig3, and Ulrich Schwarz3 — 1Ulm University — 2Otto-von-Guericke-University — 3University of Regensburg
Semipolar group III-nitrides are thought to be possible candidates for improving the problems of the so-called green gap and the efficiency droop during high current operation. The reduced piezoelectric fields lead to an improved radiative recombination probability even within thick InGaN quantum wells (QWs).
In this paper, a detailed description of the fabrication technology of 3D GaN structures providing semipolar facets will be presented. The high material quality is confirmed by structural and optical investigation methods showing that effective defect reduction can be realized. Extremely low threading dislocation density and stacking fault-free surfaces can be achieved. InGaN QWs deposited on the 3D structures show interesting phenomena as semipolar emitters. Structural properties will be explained by growth models of selective area epitaxy. Besides, the effectiveness of the method will be discussed by evaluating the internal quantum efficiency for different Indium compositions. Therefore, locally resolved measurement methods contributed from several groups are analyzed and combined. Additionally, a complete LED device is demonstrated.