Synthesis of yellow and green phosphors based on zinc orthosilicate doped by manganese at low temperature by impregnation - coprecipitation method

Abstract

This work studies the influence of magnesium concentration, sintering temperature, boric and acetic acid to synthesize yellow and green phosphors based on zinc orthosilicate doped by manganese at low temperature by a novel approach, the impregnation coprecipitation method. The samples were investigated by thermal analysis, luminescence spectroscopy, XRD, SEM and EDS. The results showed that the single-phase zinc magnesium orthosilicate/borosilicate phosphors doped by manganese with rhombo. H. axes structure of α-Zn₂SiO₄ were successfully synthesized when sintering corresponding precursors at 900°C for 45 minutes. Their luminescence efficiency is higher than that of the control samples prepared by coprecipitation method. The magnesium content for the maximum luminescence efficiency is 20 mol% per mol of metal ions. The highest luminescence product consists of spheroidal and relatively uniform particles with sizes around 0.6-1.0 µm. The variation of the precipitated precursor with temperature, the influence of sintering temperature on structure and luminescence, the mineralization role of boric acid and the chemical reactions that occur with generation of precipitated precursors and upon heating to give luminescent solid solution products are mentioned.