Effect of annealing temperature on the luminescence properties of Zn2SiO4:V nanocomposite

Yellow and green lights emitting vanadium doped Zn2SiO4 particles embedded in a SiO2 host matrix were synthesised by a sol-gel method. After the incorporation of ZnO:V nanoparticles in a silica monolith using a sol-gel method with supercritical drying of ethyl alcohol in two steps, it is heat treated in air at 1200 °C and 1500 °C for 2 h in order to obtain the α and β phases of Zn2SiO4 nanocomposites. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to characterize the phase purity, particle size and morphology. In addition, photoluminescence (PL) is used for optical studies. The PL shows a band centred at about 540 nm in the case of α-Zn2SiO4. In the case of β-Zn2SiO4, the PL reveals a band centred at about 526 nm. It is suggested that radiative defects attributed to the vanadium in the interfaces between the Zn2SiO4 particles and the SiO2 host matrix resulting from heat treatment, were responsible for theses luminescence bands.