New silicate based thermographic phosphors Ca3Sc2Si3O12:Dy, Ca3Sc2Si3O12:Dy,Ce and their photoluminescence properties

We report on the investigation of Dy3+-doped calcium scandium silicate garnet (Ca3Sc2Si3O12, abbreviated CSSG) as a high-temperature thermographic phosphor. The Ca3Sc2Si3O12:Dy and Ca3Sc2Si3O12:Dy,Ce phosphors were synthesized: (1) as single crystalline films by liquid phase epitaxy on Gd3Ga3Al2O12 (GAGG) substrates using PbO-B2O3 flux; (2) via fatty acid-assisted co-precipitation method with subsequent annealing. The resulting silicate based phosphors CSSG:Dy, CSSG:Dy,Ce were characterized by XRD, SEM, photoluminescence excitation and emission spectroscopy. Temperature dependence of the emission spectra was studied at temperatures between 293 K and 1500 K. The emission in two spectral regions corresponding to the transitions in Dy3+ ions at 458 nm and 484 nm shows different temperature sensitivity allowing for thermometry based on the intensity ratio method. The intensity ratio and the sensitivity of single crystalline films are higher than those of co-precipitated materials at temperatures up to 1200 K. It is concluded that the CSSG:Dy is a promising phosphor for high temperature measurements, with its temperature sensitivity comparable to YAG:Dy.