Using nanoindentation and cathodoluminescence to identify the bundled effect of gallium nitride grown by PA-MBE

A scanning electron microscopy (SEM) system equipped with CL allows the direct comparison of SEM images and CL maps, captured from exactly the same area of the samples. In addition to the SEM and CL images, photoluminescence spectroscopy (PL) profiling was obtained by collecting the 20 K PL spectra at the samples. The PL profiling enables the distinguishing of the emissions by the 5 meV of the blueshift from 3.440 to 3.445 eV due to localization effects. The bundled GaN NCs resulted from the (0002) reflection at 34.6° for a wurtzite structure and a raised intensity difference when the TG was increased from 700 to 850 °C. The crystal texture of the GaN can influence the mechanical properties at different TG stages.