Luminescence Properties and Decay Kinetics of Mn²⁺ and Eu³⁺ Co-Dopant Ions In MgGa₂O₄ Ceramics

The MgGa₂O₄ ceramics co-doped with Mn²⁺ and Eu³⁺ ions were synthesized via a high-temperature solid-state reaction technique. The samples with various Eu³⁺ concentrations were characterised using high-resolution photoluminescence (PL) spectroscopy. The PL spectra show weak matrix emission in a blue spectral region with dominant excitation band around 380 nm. Manganese ions are highly excited deeply in UV region and exhibit emission band peaked at 502 nm. The Eu³⁺ ions show characteristic f-f excitation and emission lines. The energy transfer between host defects and activator ions was observed. Luminescence decay curves of Mn²⁺ and Eu³⁺ emission showed complex kinetics with both Eu³⁺-ion concentration and excitation wavelength changes.