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HL: Fachverband Halbleiterphysik
HL 78: Quantum dots: Preparation and characterization
HL 78.9: Talk
Wednesday, April 2, 2014, 18:30–18:45, POT 251
Growth and characterisation of InGaN quantum dots on AlGaN-Templates — •Carsten Laurus1, Timo Aschenbrenner1, Elahe Zakizadeh1, Stephan Figge1, Detlef Hommel1, JunJun Wang2, and Ferdinand Scholz2 — 1Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee, 28359 Bremen, Germany — 2Institut für Optoelektronik, Universität Ulm, Albert-Einstein-Allee 45, 89081 Ulm, Deutschland
InGaN quantum dots (QDs) are of great interest to realize single photon emitters. Single photon emission (SPE) up to 50 K was achieved utilizing spinodal phase decomposition for QD formation. In order to improve the confinement of charge carriers in QDs and thus the temperature stability of the emission the introduction of barrier-layers with a higher bandgap energy is reasonable. However, each interface might introduce defects. Using an other template (buffer-layer) material might turns out to be a good compromise. Using InGaN as active layer, AlGaN is a promising material for templates because of its higher bandgap. Samples using GaN- and AlGaN-Templates were grown by MOVPE. For structural analysis by SEM samples without capping layer were used, whereby µ-PL investigations were made with capped samples. Based on SEM data all samples regardless from the template show a meander-like structure of different size in line with the model spinodal decomposition. Furthermore, the capping of InGaN QDs with GaN or AlGaN and its influence on the confinement will be discussed by reference to µ-PL measurements. In addition, sharp µ-PL emission lines could be traced up to 65K for samples grown on AlGaN templates.