Enhanced Photoluminescence of Gd3Al4GaO12: Cr3+ by Energy Transfers from Co-Doped Dy3+

LEDs for plant lighting have attracted wide attention and phosphors with good stability and deep-red emission are urgently needed. Novel Cr3+and Dy3+co-doped Gd3Al4GaO12garnet (GAGG) phosphors were successfully prepared through a conventional solid-state reaction. Using blue LEDs, a broadband deep-red emission at 650–850 nm was obtained due to the Cr3+ 4T2→4A2transition. When the Cr3+concentration was fixed to 0.1 mol, the crystal structure did not change with an increase in the Dy3+doping concentration. The luminous intensity of the optimized GAGG:0.1Cr3+, 0.01Dy3+was 1.4 times that of the single-doped GAGG:0.1Cr3+. Due to the energy transfer from Dy3+to Cr3+, the internal quantum efficiency reached 86.7%. The energy transfer from Dy3+to Cr3+can be demonstrated through luminescence spectra and fluorescence decay. The excellent properties of the synthesized phosphor indicate promising applications in the agricultural industry.