Resumen de Luminescent characteristics of Eu2+/Li+ doped (La-Al)2O3 phosphors and PMMA films activated with them
L. Mariscal Becerra, S. Carmona Téllez, G. Alarcón Flores, J.U. Balderas Aguilar, R. Vázquez Arreguín, H. Murrieta, C. Falcony
The effect of Li co-doping on the blue luminescence of Eu^(2+) doped (La-Al)_(2)O_(3) phosphors and its incorporation into poly (methyl methacrylate) PMMA films are reported. The phosphors were synthesized by a simple two-step process in which the (La-Al)_(2)O_(3) powders were obtained by an evaporation method, and the subsequent co-doping with Li^(+) and Eu^(2+) were made through a solid state reaction in a reductive atmosphere at 1250º C. The incorporation of those phosphors into PMMA matrix and the synthesis of films with thicknesses between 6 and 12 μm was made by drop-casting. The characteristic blue broad band emission centered at 440 nm associated with the 4f^(6)5d^(1)→ 4F^(7) transition of Eu^(2+) ions (CIE coordinates 0.6731, 0.3343) was observed when these powders were excited with 297nm light. These luminescence intensity was enhanced when Li was incorporated as co-dopant up to 320% with respect to those phosphors without Li. The luminescent characteristics of these phosphors were preserved when they were embedded into the PMMA films.
