Dresden 2011 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 17: Nitrides: Growth and Characterization
HL 17.1: Talk
Monday, March 14, 2011, 14:30–14:45, POT 51
Epitaxial GaN around ZnO nanopillars — •Mohamed Fikry1, Manfred Madel2, Ingo Tischer2, Klaus Thonke2, and Ferdinand Scholz1 — 1Institut für Optoelektronik, Universität Ulm, Albert-Einstein-Allee 45, 89081 Ulm — 2Institut für Quantenmaterie ,Universität Ulm, Albert-Einstein-Allee 45, 89081 Ulm
We report on an investigation of the epitaxial quality of GaN layers overgrown coaxially around ZnO nanopillars. In a first step, regularly arranged ZnO nanopillars were grown using pre-patterning by e-beam lithography or self-organized hexagonal polystyrene sphere masks. Alternatively, ZnO pillars were also successfully grown on top of GaN pyramids. In a second step, GaN layers were grwon around the ZnO pillars by Metal Organic Vapor Phase Epitaxy. At growth temperatures above 800 °C, the ZnO pillars are dissolved by the hydrogen carrier gas leaving hollow GaN nanotubes. Characterization involved photoluminescence (PL), scanning electron microscopy and cathodoluminescence. The fair quality of the deposited GaN layers is confirmed by a sharp low temperature PL peak at 3.48 eV attributed to the donor bound exciton emission. Further peaks at 3.42 eV and 3.29 eV show the possible existence of basal plane and prismatic stacking faults.