Direct evidence of single quantum dot emission from GaN islands formed at threading dislocations using nanoscale cathodoluminescence: A source of single photons in the ultraviolet

• DOI: 10.1063/1.4922919
• Publication Date: 2015-06-22T17:00:20Z
• Authors: Gordon Schmidt; Christoph Berger; Peter Veit; Sebastian Metzner; Frank Bertram; Jürgen Bläsing; Armin Dadgar; André Strittmatter; Jürgen Christen; Gordon Callsen; Stefan Kalinowski; Axel Hoffmann
• Keywords: 0103 physical sciences; 01 natural sciences

Intense emission from GaN islands embedded in AlN resulting from GaN/AlN quantum well growth is directly resolved by performing cathodoluminescence spectroscopy in a scanning transmission electron microscope. Line widths down to 440 μeV are measured in a wavelength region between 220 and 310 nm confirming quantum dot like electronic properties in the islands. These quantum dot states can be structurally correlated to islands of slightly enlarged thicknesses of the GaN/AlN quantum well layer preferentially formed in vicinity to dislocations. The quantum dot states exhibit single photon emission in Hanbury Brown-Twiss experiments with a clear antibunching in the second order correlation function at zero time delay.