Figure 2
From: On the phenomenon of large photoluminescence red shift in GaN nanoparticles
Emission spectra of GaN epitaxy and GaN NPs, peak PL photon energy and FWHM dependence. (a) Normalized 77 K μPL emission spectra of as-grown 30-μm GaN epitaxy and GaN NP cluster with semi-log scale. (b) Normalized room temperature μPL emission spectra of as-grown GaN (dashed line) and GaN NP (solid line) cluster excited with increasing laser power (0.08, 0.8, 2, 4, and 8 kW/cm2). (c) The peak PL photon energy (black squares) and the FWHM (blue triangles) dependence over the excitation power.