Enhanced Photoluminescence of Gd(3)Al(4)GaO(12): Cr(3+) by Energy Transfers from Co-Doped Dy(3+)

LEDs for plant lighting have attracted wide attention and phosphors with good stability and deep-red emission are urgently needed. Novel Cr(3+) and Dy(3+) co-doped Gd(3)Al(4)GaO(12) garnet (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 Cr(3+ 4)T(2) → (4)A(2) transition. When the Cr(3+) concentration was fixed to 0.1 mol, the crystal structure did not change with an increase in the Dy(3+) doping concentration. The luminous intensity of the optimized GAGG:0.1Cr(3+), 0.01Dy(3+) was 1.4 times that of the single-doped GAGG:0.1Cr(3+). Due to the energy transfer from Dy(3+) to Cr(3+), the internal quantum efficiency reached 86.7%. The energy transfer from Dy(3+) to Cr(3+) can be demonstrated through luminescence spectra and fluorescence decay. The excellent properties of the synthesized phosphor indicate promising applications in the agricultural industry.