Effect of doping element on non-contact luminescence thermometry properties of nanocomposite SiO₂/Zn₂SiO₄:X (X=Mn, V, Ca)

Doped zinc silicate nanoparticles (Zn2SiO4) embedded in the SiO2 host matrix, were prepared by the sol-gel method. First, doped zinc oxide (ZnO) nanoparticles were synthesized by the solvothermal route and then confined in a monolithic silica (SiO2) matrix by the sol-gel route. Finally, SiO2/Zn2SiO4:X (X = Mn, V, and Ca) nanocomposites were obtained by a simple solid-state reaction for 2 h at 1200 degrees C under a natural atmosphere. Structural, morphological, and optical properties of the different samples were investigated. The X-ray diffraction (XRD) pattern showed that rhombohedral alpha-Zn2SiO4 is the most dominant crystalline phase at high temperatures for all samples. Transmission electron microscopy (TEM) images revealed that the average grain size of the samples is about 70 nm. Photoluminescence (PL) spectra depict the presence of wide visible range emission; yellow, green, and red for Mn, V, and Ca respectively. The obtained results make doped-Zn2SiO4 nanophosphor a potential candidate for optoelectronic devices. For the different samples, the PL intensity increases linearly when the measurement temperature decreases. In light of this observation, it can be predicted that this material is promising for several technological applications, in particular for non-contact luminescence thermometry.