Luminescence of Tb-doped Ca3Y2(Si3O9)2 oxide upon UV and VUV synchrotron radiation excitation

Powders of calcium yttrium silicate, Ca3Y2(Si3O9)2, containing 0.1–3% Tb3+ were prepared using a sol-gel method and characterized with XRD, IR, UV–vis and UV–VUV spectroscopies at room temperature and 10 K. Structural analysis revealed pure monoclinic phase of Ca3Y2(Si3O9)2 after heat-treatment at 1000 °C. Infrared spectroscopy showed that between 800 and 900 °C a short-range structural organization of the components proceeded, yet without crystallization. A strong emission of Tb3+ had been observed both in the green part of the spectrum due to the 5D4→7FJ transitions and in the blue-violet region owing to the 5D3→7FJ radiative relaxation. The color of the light could be tuned from yellowish-green to bluish-white both by means of the dopant content and the temperature of synthesis. Efficient luminescence of Tb3+-doped Ca3Y2(Si3O9)2 phosphors could also be obtained upon stimulation with vacuum ultraviolet synchrotron radiation demonstrating that an energy transfer from the host to the Tb3+ ions takes place.

Luminescence of Ca3Y2(Si3O9)2:Tb covers the whole visible region of electromagnetic spectrum and the relative intensity of the blue part against the green one depends on the activator content and technological parameters of preparation.Figure optionsDownload as PowerPoint slideHighlights
► VUV–UV–vis luminescence of Ca3Y2(Si3O9)2:Tb at RT and 10 K was analyzed.
► Tb3+ ion can be excited directly or through the host lattice.
► Specific structure of the host allowed to get intense 5D3→7FJ luminescence.
► At 10 K an exciton is formed and radiatively relaxes with the use of a defect.