Studies on the photoluminescence behavior of rare earth (Ce, Sm Eu, Dy, Tb) activated calcium magnesium silicate phosphors

Abstract

The calcium magnesium silicate (CaMgSi 2 O 6 ) phosphor activated with the trivalent/divalent rare-earth ions R 3? /R 2? (R 3? /R 2? = Ce 3? ; Sm 3? ; Eu 3? ; Eu 2? ; Dy 3? and Tb 3? ) ions were synthesized by the solid state reaction method. The crystal structure and luminescence properties were investigated by X-ray diffraction and photoluminescence analysis in detail. The crystal structures of sintered phosphors were monoclinic structure with space group C2/ c. The excitation spectra of CaMgSi 2 O 6 :R 3? /R 2? indicated that all samples could be effectively excited by near UV light. Emission spectra of the samples have emitted strong violet-blue, orange-red, blue, near white light and green light, due to the characteristic transitions of Ce 3? ; Sm 3? ; Eu 3? ; Eu 2? ; Dy 3? and Tb 3? respectively. Thus, based on the favorable photoluminescence properties under the near UV light excitation, these phosphors could be nicely suitable for the white light emitting diodes.

Controlling the europium oxidation state in diopside through flux concentration

“…22,23 The solid-state synthesis of CaMgSi 2 O 6 is usually performed using a flux to obtain a single-phased, well-crystallized product. 18,19,[23][24][25][26][27][28][29] In this work, we describe the research conducted on the CaMgSi 2 O 6 matrix doped with europium and co-doped with aluminium ions to tune the oxidation states of europium in the material. The solid-state synthesis allowed us to obtain different series of CaMgSi 2 O 6 -based luminescent materials.…”

“…22,23 The solid-state synthesis of CaMgSi 2 O 6 is usually performed using a flux to obtain a single-phased, well-crystallized product. 18,19,23–29…”

Processos de síntese de pós cerâmicos a base de diopsita dopada com disprósio para materiais luminescentes emissores de luz branca

“…Recentemente, a diopsita (CaMgSi2O6) vem sendo aplicada como material luminescente em lâmpadas fluorescentes, tubos de raios catódicos, painéis de plasma e LEDs, em virtude de sua alta estabilidade térmica e química [16,17]. Ela também tem atraído o interesse de pesquisadores, devido a suas aplicações em outras áreas, tais como, em biomateriais, revestimentos, imobilização de resíduo nuclear e também como material selante em células combustível de óxido sólido (SOFC) [18].…”

“…Além dessas duas classes de materiais, foram descobertos poucos materiais que exibem luminescência persistente quando dopados com Eu 2+ [53,54]. O processo de substituição de íons Ca 2+ por íons Dy 3+ está representado na Equação 4[8,15,17]. de saídas de emergência; o material deve apresentar a luminância mínima de 0.32 mcd/m², após 340 minutos (5 horas e 40 minutos).…”