Synthesis and enhanced blue emission of Eu2+-doped GaN/SiO2 nanocomposites by addition of SiO2 nanoparticles

The enhanced blue emission of Eu2+-doped GaN/SiO2 nanocomposites prepared through the nitridation process in an Ar environment containing 5% H-2 and NH3 gas at 1000 degrees C was investigated as a function of the amount of SiO2 nanoparticles added. The X-ray diffraction patterns indicate that the Eu2+-doped GaN/SiO2 nanocomposites consisted of a powder mixture of Eu2+-doped GaN and amorphous SiO2 particles. The back-scattering electron image and mapping data indicate that the SiO2 nanoparticles enclose the Eu2+-doped GaN nanoparticles to form aggregates. The red shifted peaks for the Ga-N bonds observed in the Fourier transform infrared spectra were attributed to the formation of GaOxNy and GaN intermediates. Strong emission and shoulder peaks of the Eu2+-doped GaN/SiO2 nanocomposites were observed at around 470 nm and 450 nm upon the addition of SiO2. respectively. The Eu2+-doped GaN/SiO2 nanocomposites showed the highest blue emission intensity at 0.15 mol% of SiO2 nanoparticles. (C) 2012 Elsevier B.V. All rights reserved.