Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 61: GaN: Preparation and Characterization II (mainly structural)

HL 61.1: Talk

Wednesday, March 28, 2012, 15:00–15:15, EW 202

Effect of the growth conditions on the early stages of pyramidal semipolar template growth — •Jan Wagner, Clemens Waechter, Julian Mack, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen and Research Center SCoPE, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany

The nitride material system is in the focus of many research studies for several years now because of the large tunability of the emission energy over the visible range. A challenge that occurs is the huge influence of the Quantum Confined Stark Effect (QCSE) which reduces the emission efficiency dramatically. One approach to manage this problem is the use of native non- or semi-polar substrates which are still quite expensive. A promising alternative for those substrates is the use of semipolar surfaces grown by epitaxial lateral overgrowth (ELO). The growth of active layers on the facets of GaN pyramids re- duces the QCSE and therefore enhances the emission efficiency. Since the pyramid facets serve as growth template for the active region, their crystalline quality directly affects the emission efficiency. This contribution therefore deals with the early growth stages of the GaN pyramids grown at different growth times and growth conditions. The structural investigation reveal the internal defects and gives an insight on the material quality in the pyramids and their facets.