In their
Nano Express article, Loeto
et al. report on the study of point defects in InGaN/GaN core–shell nanorods and the role of the regrown interface. Monochromatic cathodoluminescence microscopy of the nanorod cross section showed a ring-like region of lower intensity of the near-band-edge emission. This ring-like region was related to the regrowth interface formed during the fabrication process of the nanorods. The combination of scanning transmission electron microscopy (STEM) and cathodoluminescence (CL) hyperspectral mapping of the same sample regions revealed that the dark ring likely originates from an agglomeration of point defects associated with observed donor-acceptor pair emission. These point defects limit the radiative efficiency close to the regrowth interface.