Luminescence and structural analysis of Ce 3+ and Er 3+ doped and Ce 3+ –Er 3+ codoped Ca 3 Sc 2 Si 3 O 12 garnets: influence of the doping concentration in the energy transfer processes

• Published in: RSC advances 2016, Vol.6 (18), p.15054-15061
• Main Authors: Fernández-González, R., Velázquez, J. J., Rodríguez, V. D., Rivera-López, F., Lukowiak, A., Chiasera, A., Ferrari, M., Gonçalves, R. R., Marrero-Jerez, J., Lahoz, F., Núñez, P.
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C5RA22630A

We present research on Ca 3 Sc 2 Si 3 O 12 garnets doped with Ce 3+ and Er 3+ ions that were synthesized by the freeze-drying precursor method. The structural characterization was performed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Scanning electron microscopy (SEM) images of the calcined material were studied. Nanocrystals of Ca 3 Sc 2 Si 3 O 12 were obtained by calcining the precursor at 1200 °C for 4 h with a mean size of about 100 nm. The luminescence features of Ce 3+ and Er 3+ doped samples indicated that these ions are effectively incorporated into the crystalline phase. In addition, codoping with Ce 3+ –Er 3+ ions results in energy transfer processes from Ce 3+ to Er 3+ ions which led to the enhancement of near-infrared luminescence at 1.5 μm. The efficiency of this non-radiative energy transfer process has been studied by means of excited state dynamics as a function of the doping concentration. From these results we have found that near-infrared Er 3+ luminescence efficiency under VIS Ce 3+ excitation is at maximal for 1Ce 3+ –1Er 3+ codoped Ca 3 Sc 2 Si 3 O 12 garnets (in mol%). Luminescence quenching at higher Er 3+ ion concentrations is observed.