Synthesis of gallium nitride quantum dots through reactive laser ablation

Abstract

Nanocrystalline GaN was synthesized through reactive laser ablation of gallium metal in a N2 atmosphere. X-ray diffraction, selected-area electron diffraction, and transmission electron microscopy measurements show that the GaN crystallites are as small as 2 nm in diameter, and follow a log-normal size distribution with a mean particle diameter of 12 nm. Size-selective photoluminescence and photoluminescence excitation spectroscopy reveal a continuous range of blueshifted band-edge emissions and absorptions starting from the bulk value for gallium nitride and continuing to below 300 nm. These results are consistent with a GaN particle size distribution that encompasses regions above and below the excitonic-Bohr radius of GaN, such that the GaN material shows combined bulk and quantum confined optical properties.

Synthesis of Monodisperse Ultrapure Gallium Nitride Nanoparticles by MOCVD

“…These results arise from the fact that gallium has a low reactivity with ammonia, and reacts even more sluggishly with molecular nitrogen. Goodwin et al proposed the use of a laser ablation method under molecular nitrogen to produce GaN, [10] but it was necessary to refill supplemental nitrogen by annealing under an ammonia atmosphere. Several significant studies have also been reported on colloidal nanoparticles of Group 13 nitride.…”

Antiferromagnetic order in (Ga,Mn)N nanocrystals: A density functional theory study

“…However, it is expected from the evidence of 2 nm undoped nanoparticles of GaN already synthesized. 21 Hence, our calculations anticipate future experimental work with small doped dots. The theoretical and computational details are given in Sec.…”

Solution Synthesis of Colloidal Gallium Nitride at Unprecedented Low Temperatures

“…[16] From these comparisons the conclusion can be drawn that the observed strong and easily visible blue luminescence of our samples A±C is very likely to arise from colloidal GaN particles. The intrinsic bandgap luminescence of pure crystalline bulk GaN is observed at 3.45 eV.…”