PHOTOLUMINESCENCE PROPERTIES OF Cr3+ AND Mn4+ CO-DOPED Y3Al5O12/YAlO3 MATERIALS SYNTHESIZED BY A SOLID STATE REACTION METHOD

Abstract

Red to far-red emitting Mn⁴⁺ and Cr³⁺ co-doped Y₃Al₅O₁₂/YAlO₃ YAG/YAP:(Cr³⁺, Mn⁴⁺) phosphors were successfully synthesized using a solid-state reaction method at high temperature. X-Ray diffraction results indicate that Cr³⁺ and Mn⁴⁺ ions simultaneously replace Al³⁺ ions in the octahedral [AlO₆] sites of both host lattices, YAG and YAlO₃. Field emission scanning electron microscope images show that the YAG/YAP:(Cr³⁺, Mn⁴⁺) materials annealed at 1500 °C have a particle size of approximately 2 mm. Photoluminescence and photoluminescence excitation spectra analysis reveal that the YAG/YAP:(Cr³⁺, Mn⁴⁺) materials exhibit strong emission in the red to far-red region, peaking at 694 nm, and show good excitation at wavelengths of 404 nm and 560 nm. The maximum photoluminsecence intensity was recorded for the YAG/YAP sample doped with 1.3% Cr³⁺ and 0.05% Mn⁴⁺, which was annealed at 1500 °C for 5 hours in air. The presence of co-doped Mn⁴⁺ ions enhanced the emission intensity of the YAG/YAP:1.3%Cr³⁺ sample by 3.47 times compared to the YAG/YAP:1.3%Cr³⁺ sample without co-doping. This enhancement is attributed to the energy transfer process from Mn⁴⁺ ions to Cr³⁺ ions within the YAG/YAP lattices. The results obtained demonstrate that Y₃Al₅O₁₂/YAlO₃:Cr³⁺ co-doped with Mn⁴⁺ ions has significant potential for applications in plant growth LEDs.