Red-Shifted Emission in Y3MgSiAl3O12:Ce3+ Garnet Phosphor for Blue Light-Pumped White Light-Emitting Diodes

It is highly desirable to red shift the emission of Y3Al5O12:Ce3+ phosphor to obtain a warmer correlated color temperature (CCT) in applications for blue light pumped white-light emitting diodes (w-LEDs) with high color rendering index (CRI). In this paper, we report the red-shifted emission of Y3MgSiAl3O12:Ce3+ garnet phosphor for w-LEDs through a chemical unit cosubstituting in a solid solution design strategy. The fabrication temperature of the Y3MgSiAl(3)O(12):Ce3+ powder was optimized at 1600 degrees C, and its structure, photoluminescence property, micromorphology, decay curve, quantum yield, as well as the thermal stability of the samples are investigated in detail. The as-prepared Y3MgSiAl3O12:Ce3+ phosphors display a broad excitation band ranging from 300 to 520 nm (centered at 450 nm) and present an intense Ce3+ 5d-4f emission band in the yellow light region (lambda(em) = 564 nm, obviously red-shifteaway from Y3Al5O12:Ce-3). This can be explained by the increase of the crystal-field splitting in the Ce3+ 5d levels owing to the chemical unit cosubstitution of Al3+(I) and Al3+(II) ions by Mg2+ and Si' ions. The quantum yield of the Y2.92MgSiAl3O12:0.08Ce(3+) phosphor is measured as 61.8%. Further investigation on a lamp packaged w-LEDs combining 12:0.08Ce(3+) Y2.92MgSiAl3O12:0.08Ce(3+) phosphors on a blue InGaN chip shows it to exhibits a lower CCT and higher CRI compared to those of the commercial Y3Al5O12:Ce3+-based devices, indicating their appealing strengths for potential applications in w-LEDs.