Dresden 2014 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 78: Quantum dots: Preparation and characterization

HL 78.9: Vortrag

Mittwoch, 2. April 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.