Time-resolved luminescence and excitation spectroscopy of Co-doped Gd 3 Ga 3 Al 2 O 12 scintillating crystals

• Published in: Scientific reports Vol. 10; no. 1; p. 20388
• Main Authors: Pankratova, Viktorija, Kozlova, Anna P, Buzanov, Oleg A, Chernenko, Kirill, Shendrik, Roman, Šarakovskis, Anatolijs, Pankratov, Vladimir
• Format: Journal Article
• Language: English
• Published: England 23.11.2020
• ISSN: 2045-2322

Cerium doped Gd Ga Al O (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg , Ca ) and tetravalent (Zr , Ti ) ions have been studied by means of time-resolved luminescence as well as the excitation luminescence spectroscopy in vacuum ultraviolet (VUV) and soft X-ray (XUV) spectral range. Tunable laser excitation was applied for time-resolved experiments in order to obtain luminescence decay curves under excitations in Ce , Gd and excitonic absorption bands. The influence of the co-dopant ions on the Ce luminescence decay kinetics is elucidated. The fastest luminescence decay was observed for the Mg co-doped crystals under any excitation below bandgap energy indicating the perturbation of the 5d states of Ce by Mg ions. Synchrotron radiation was utilized for the luminescence excitation in the energy range from 4.5 to 800 eV. Special attention was paid to the analysis of Ce excitation spectra in VUV and XUV spectral range where multiplication of electronic excitation (MEE) processes occur. Our results demonstrated that GGAG:Ce single crystals co-doped by Mg ions as well as the GGAG:Ce crystal annealed in vacuum reveal the most efficient excitation of Ce emission in VUV-XUV excitation range. The role of intrinsic defects in MEE processes in the co-doped as well as in the annealed GGAG:Ce single crystals is discussed.