Strong deep-UV and visible luminescence from GaN nanoparticles

This paper reports strong deep-ultraviolet and visible photoluminescence (PL) of the GaN nanoparticles depending on the conversion time from Ga2O3 to GaN. Monoclinic β-Ga2O3 nanoparticles with a diameter of approximately 2.5–5.0 nm were fabricated prior to conversion to GaN. The Ga2O3 nanoparticles were converted to GaN in the tube furnace with NH3 flow at 900°C for 10, 30, 60, and 120 min. Depending on the conversion time, the converted GaN nanoparticle size became bigger with the increase of the conversion time. The characteristic GaN x-ray diffraction (XRD) peaks became bigger when the conversion time increased. The PL intensity drastically increased with the increase of the conversion time. The spectra profile completely overlapped for GaN samples converted for 10, 30, and 60 min, with the maximum peak at 390 nm. However, the PL spectrum slightly narrowed and red-shifted with the maximum peak at 400 nm for the GaN nanoparticles converted for 120 min.