Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 4: GaN: Preparation and Characterization I (mainly Optics)

HL 4.8: Talk

Monday, March 26, 2012, 11:15–11:30, EW 201

Local changes in the growth of the active region on semipolar templates produced by ELO — •Clemens Waechter, Julian Mack, Ulrich Rengstl, Elisabeth Koroknay, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen und Research Center SCoPE, Universität Stuttgart, Allmandring 3, 70569 Stuttgart

The growth on semipolar substrates is in the focus of material research as the active regions grown on semipolar substrates are less influenced by the Quantum Confined Stark Effect (QCSE). Since the production of native semipolar substrates is still very resource (and therefore cost) intensive, the growth on semipolar templates produced by epitaxial lateral overgrowth (ELO) on sapphire substrates offers a less expensive approach. Next to this, the properties of the grown template change the local growth conditions of the following layers. For example, the different strain situations for InGaN layers grown on pyramidal GaN templates lead to an increased Indium incorporation on the edges and apex. Also, depending on the locally available growth area, there are local changes in the growth conditions due to transport processes in the gas phase. For this contribution, pyramidal templates were produced by ELO. The size and density of the pyramids are controlled by the growth mask. After the growth, photoluminescence measurements (PL) were performed. In these measurements, we observe a strong influence of the pyramid density on the local emission spectra of the InGaN layer. The results of these measurements shall be presented and discussed in this contribution.