Regensburg 2019 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 13: Focus Session: GaN-based single photon emitters
HL 13.3: Hauptvortrag
Dienstag, 2. April 2019, 10:30–11:00, H31
Growth of desorption-induced GaN quantum-dots — •Christoph Berger1, Gordon Schmidt1, Hannes Schürmann1, Sebastian Metzner1, Peter Veit1, Jürgen Bläsing1, Frank Bertram1, Armin Dadgar1, Jürgen Christen1, André Strittmatter1, Stefan Kalinoswki2, Stefan T. Jagsch2, Gordon Callsen2, Markus R. Wagner2, and Axel Hoffmann2 — 1Institute of Physics, Otto-von-Guericke-University Magdeburg — 2Institute of Solid State Physics, Technical University Berlin
We studied the MOVPE-growth of thin GaN films on top of AlN/sapphire-templates. After the deposition of a few monolayers GaN at 960°C, a growth interruption (GRI) with durations between 0 s and 60 s without ammonia supply was applied to allow for quantum dot formation. Each quantum dot (QD) structure was capped with AlN grown at 1195°C. Without a GRI, a continuous GaN layer with additional hexagonally-shaped truncated pyramids forms. On the other hand growth interruptions lead to desorption of GaN resulting in smaller islands without definite form located in close vicinity to threading dislocations. Ultra narrow line widths in the spectral range from 220 nm to 310 nm are observed from these islands and single photon emission is verified by Hanbury Brown-Twiss experiments. Aiming for efficient single photon sources realized as resonant cavity structures, such quantum dots were also grown on deep-UV AlGaN/AlN distributed Bragg reflectors with maximum reflectivities of 98 %.