Effects of aluminum co-doping on photoluminescence properties of Ce3+-doped SiO2 glasses

SiO2 glasses co-doped with Al3+ ions were prepared by a sol-gel method by holding 0.5% of Ce3+ ions constant and varying the Al3+ ions concentrations. Thermal stability, the structural, chemical and the optical properties of the samples were studied by using differential scanning calorimetric (DSC), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), UV-vis spectroscopy and photoluminescence spectroscopy (PL). The DSC and TGA of samples depicted that the presence of dopant and co-dopant decreased the endothermic peak temperature and the yield respectively. SEM images showed that the particles were in the nano-range and spherical in shape. The XRD showed that all the samples were amorphous. The UV absorption measurements indicated that the presence of Al3+ ions significantly reduced the SiO2 absorption band, increased the absorbance intensity of SiO2 and decreased the transmittance as compared to the presence of the Ce3+ ions alone. The photoluminescence results displayed an optimum increase in luminescence intensity when the ratio of Al: Ce was 10:1 and further increase in aluminum content quenched the luminous intensity.