Structural Investigation and Energy Transfer of Eu3+/Mn4+ Co-Doped Mg3Ga2SnO8 Phosphors for Multifunctional Applications

In recent years, rare earth ion and transition metal ion co-doped fluorescent materials have attracted a lot of attention in the fields of WLEDs and optical temperature sensing. In this study, I successfully prepared the dual-emission Mg₃Ga₂SnO₈:Eu³⁺,Mn⁴⁺ red phosphors and the XRD patterns and refinement results show that the prepared phosphors belong to the Fd-3m space group. The energy transfer process between Eu³⁺ and Mn⁴⁺ was systematically investigated by emission spectra and decay curves of Mg₃Ga₂SnO₈:0.12Eu³⁺,yMn⁴⁺ (0.002 ≤ y ≤ 0.012) phosphors and the maximum value of transfer efficiency can reach 71.2%. Due to the weak thermal quenching effect of Eu³⁺, its emission provides a stable reference for the rapid thermal quenching of the Mn⁴⁺ emission peak, thereby achieving good temperature measurement performance. The relative thermometric sensitivities of the fluorescence intensity ratio and fluorescence lifetime methods reached a maximum value of 2.53% K^-1 at 448 K and a maximum value of 3.38% K^-1 at 473 K. In addition, the prepared WLEDs utilizing Mg₃Ga₂SnO₈:0.12Eu³⁺ phosphor have a high color rendering index of 82.5 and correlated color temperature of 6170 K. The electroluminescence spectrum of the synthesized red LED device by Mg₃Ga₂SnO₈:0.009Mn⁴⁺ phosphor highly overlaps with the absorption range of the phytochrome P_FR and thus can effectively promote plant growth. Therefore, the Mg₃Ga₂SnO₈:Eu³⁺,Mn⁴⁺ phosphors have good application prospects in WLEDs, temperature sensing, and plant growth illumination.