Tunable Luminescence and Temperature Sensing in Tb3+ mono-doped Mg3Gd2Ge3O12 Phosphor with High Quantum Yield

Jinping Bai, Jinsu Zhang*, Chunying Kong, Bingye Zhang, Yongze Cao, Yichao Wang, Xizhen Zhang, Baojiu Chen*, Kang Li*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The phosphors of Tb3+ doped Mg3Gd2Ge3O12 were synthesized by a solid-state method. Two groups of emission can be gained, 5D3→7FJ (J=6,5,4,3,2) and 5D4→7FJ (J=6,5,4,3) , respectively. The color of Mg3Gd2Ge3O12:Tb3+ undergoes a blue-green shift with different concentrations of Tb3+, which is attributed to the cross-relaxation process. The Dexter and Inokuti-Hirayama models are employed to analyze the energy transfer mechanism, rate, and efficiency between Tb3+ ions. The results indicate that the type of energy transfer is primarily dipole-dipole interaction, and the critical distance is 19.57 Å. The maximum energy transfer rate and efficiency are found to be 69.65% and 98.5%, respectively. Furthermore, we observed a very interesting phenomenon: as the temperature changes from 303 K to 573 K, the luminescent color of Tb3+ varies, particularly in samples with low doping concentrations, where this change is quite pronounced. This has been rarely reported in previous literature. We conducted a detailed study on the temperature-dependent changes in luminescent color, attributing this phenomenon to the good matching of phonon energy with the energy gap between the 5D3 and 5D4. Moreover, this phenomenon could be applied in fluorescence temperature sensing and thermos-chromic applications with good repeatability via temperature cycling testing. The greatest Sr is 1.1 %K-1 at 495 K of Mg3Gd2Ge3O12:1%Tb3+. The maximum quantum yield can reach 97.91% in this system.
Original languageEnglish
JournalCeramics International
Volume00
Issue number00
Early online date27 Feb 2025
DOIs
Publication statusE-pub ahead of print - 27 Feb 2025

Keywords

  • Mg3Gd2Ge3O12:Tb3+
  • energy transfer
  • temperature sensing
  • thermos-chromic

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