In this communication, we present results on preparation of GaN nanoparticles by conversion of Ga2O3 nanocrystals in a flow of NH3 and H2. The monoclinic Ga2O3 nanoparticles have been prepared by hydrothermal method with gallium nitrate and sodium hydroxide as precursors. Ga2O3 nanowires are produced with increasing the duration of the hydrothermal process up to 24 hours. The production of β-phase Ga2O3 has been confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. According to XRD, Raman and FTIR spectra, wurtzite type GaN nanocrystals with an average size of 28.6 nm are obtained by nitridation of Ga2O3 nanoparticles. Doping of Ga2O3 nanomaterial with Eu3+ ions in the hydrothermal process is demonstrated, and the emission spectra of this Eu-doped nanomaterial are compared with those of Eu-doped nanoparticles prepared previously by solid state reactions.
In this communication, we present results of investigations of the influence of technological conditions upon the properties of GaP nanoparticles produced by using a new precursor as a source of Ga atoms. The obtained nanoparticles were investigated by means of XRD, EDAX, and ТЕМ as well as by means of Raman light scattering and photoluminescence spectroscopy. The sizes of nanoparticles obtained with gallium acetylacetonate as a source of gallium are in the range of 10-40 nm according to estimations from TEM analysis. These values correlate with the position of the short-wavelength emission maximum in the photoluminescence spectra. A method of electrophoretic deposition of GaP nanoparticles from colloidal organosol solutions was elaborated. Raman spectra and XRD patterns, as well as optical transmission spectra have been measured for layers of GaP nanoparticles produced by this method.
ZnO-based red phosphors were prepared by different methods. One phosphor was grown from a Na2B4O7 melt, and another one was prepared from a ZnO:Eu2O3 powder via electron beam treatment. The e-beam processing is found to result in the formation of a high quality layer on the surface of ZnO:Eu2O3 powder. The analysis of the emission related to the Eu3+ 4f-4f intrashell transitions suggests that the phosphor grown from the Na2B4O7 melt represents a nanocomposite consisting of ZnO and Na2B4O7 nanoparticles, a part of Eu3+ ions being incorporated into ZnO and another part into Na2B4O7 constituent, while in the phosphor prepared from ZnO:Eu2O3 powder Eu3+ ions are selectively incorporated into the Zn sublattice of the ZnO host.