AI Article Synopsis

  • Gadolinium-yttrium-aluminum-gallium garnets (GYAGG) were developed as ceramics doped with Eu, Tb, and Ce for use as long-wavelength phosphors in bright white light sources using cathodoluminescence (CL).
  • The light yield (LY) of the Tb-doped ceramics significantly outperformed the traditional YAG:Ce phosphor, although adding Eu to shift color reduced the LY to that of YAG:Ce.
  • Mixing Tb- and Eu-doped GYAGG powders could enhance LY further, with the Gd sublattice aiding excitation transfer, and the phosphors' chromaticity can be adjusted by changing the concentration ratios of Tb and Eu.

Article Abstract

Gadolinium-yttrium- aluminum-gallium garnets (GYAGG) doped and codoped with Eu, Tb, and Ce were manufactured as ceramics to develop long-wavelength phosphors for high-brightness white light sources based on cathodoluminescence (CL). The CL light yield (LY) of Tb-doped ceramics at high-intensity electron beam excitation is shown to be more than twice as high as that of the conventional phosphor YAG:Ce, whereas codoping with Eu to redshift the chromaticity results in reducing the LY approximately to the level of YAG:Ce. The LY might be substantially improved by using a mix of Tb- and Eu-doped GYGAG powders instead of a single codoped GYGAG to produce ceramic phosphor. The high LY is explained by favorable contribution of Gd sublattice in excitation transfer to activator ions. Chromaticity of phosphors GYGAG:Tb, Eu can be tuned in a wide range by varying the ratio of Tb to Eu concentration. They are radiation resistant and stabile in the temperature range from 300 to 450 K.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9418208PMC
http://dx.doi.org/10.1016/j.heliyon.2022.e10193DOI Listing

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