Growth and spectroscopy of Gd3Ga3Al2O12 (GGAG) and evidence of multisite positions of Sm3+ ions in solid solution matrix

• Gd3Ga2Al2O12:Sm3+ (GGAG) single crystals has been grown by Czochralski method.
• Multisite positions of Sm3+ ion in GGAG solid solution crystal have been observed.
• Influence of temperature onto spectroscopic properties has been discussed.
• The Judd-Ofelt intensity parameters and branching rations of luminescence has been calculated and discussed.
• The material has been proposed to be a new orange and efficient phosphor.

Single crystal of Gd3Ga3Al2O12 (GGAG) doped with 1 at.% Sm3+ was fabricated by the Czochralski method. Optical absorption and emission spectra as well as luminescence decay curves for this crystal was recorded at different temperatures ranging from 5 K to 300 K. The energies of the crystal field sublevels of selected multiplets were determined based on optical spectra recorded at T = 5 K. It has been found that widths of emission spectral lines related to transitions between individual crystal field levels of multiplets are stable up to 100 K, then new Stark component of higher the 4G5/2 multiplets starts to appear in the spectrum. The spectral widths (FWHM) are in the range 7–30 cm−1 what is caused with solid solution composition of the crystal. Five local positions of the Sm3+ have been found in this material. Judd-Ofelt calculation of branching ratios has been done. The color of luminescence is orange-red with CIE coordinates as x = 0.606 and y = 0.393 and the total efficiency 45%.

We report the synthesis and temperature-dependent (5–300 K) studies of Gd3Ga2Al2O12 (GGAG) activated with Sm3+ ions. This compound is very efficient orange-red phosphor. The properties of this compound has been analyzed in the frame of Judd-Ofelt model based on its spectroscopic properties.Figure optionsDownload as PowerPoint slide