Extended Data Fig. 4: Plan-view scanning electron microscopy (SEM)-CL and cross-sectional polarization-resolved SEM-CL spectra of Mg-intercalated p-type GaN.
From: Observation of 2D-magnesium-intercalated gallium nitride superlattices
a, Cross-sectional schematic illustrations of the p-type GaN with and without MiGs nanostructures. The p-type GaN was initially grown by MOVPE, featuring in-situ Mg doping at a density of 6 × 1018 cm−3. b, SEM image (in secondary electron mode) displaying the plan-view morphology of a typical Mg-annealed GaN surface (surface of the p-GaN with MiGs nanostructure). c, Integrated CL spectra image mapping the position of peak centre energy around the near-band-edge (NBE) emission. The imaged region corresponds to that shown in b. d, Localized spectra of NBE at the three sampling points indicated in c. e, Schematic illustration of the polarization-resolved CL spectroscopy setup (0° and 90°). f, Polarization-resolved CL spectra of the p-type GaN samples with and without MiGs nanostructures. This shows the CL intensities of transverse magnetic (TM) (0° polarization) and transverse electric (TE) (90° polarization) emissions in both the NBE band and yellow luminescence band. The p-type GaN with MiGs nanostructures demonstrates an increased TM emission in the yellow luminescence band.
