A New Efficient Deep-Red-Emission Phosphor Y3Al4.9Sb0.1O12: Ce3+, Cr3+ with Application Potential in Plant Growth

Aiming at a system of more efficient plant growth, cationic substitutions for garnet-structure host crystal activated by Ce 3+ and Cr 3+ are investigated. A series of Y 3 Al 5 O 12 : Ce 3+ -Cr 3+ , red-emitting materials excited by near-ultraviolet and blue light with a peak emission near 693 nm, are synthesized using a solid-state method. The substitution of Sb 3+ for Y 3 Al 5 O 12 : Ce 3+ , Cr 3+ is found to increase the emission intensity of deep red about +80% because it improves the energy transfer from Ce 3+ to Cr 3+ , where yellow emission of Ce 3+ is depressed and deep red of Cr 3+ increased. It also enhances the intensity-ratio of zero phonon line (ZPL) vs phonon assisted side band. It is induced that the substitution of Sb 3+ having strong covalent property influences symmetric Ce 3+ O 2– 6 octahedron, significantly increasing the intensity of 2 E→ 4 A 2 ZPL of Cr 3+ under the resonance energy transfer of Ce 3+ to Cr 3+ . From the ratio of Ce 3+ emission intensity in the absence and presence of Cr 3+ , the energy transfer has a mechanism of dipole-quadrupole interaction. By using Sb 3+ substitution and flux AlF 3 , the original emission intensity of Y 3 Al 5 O 12 : Ce 3+ , Cr 3+ is increased about +183%. The new phosphor has application potential for plant growth in both methods of using LED and converting Sunlight.