Luminescence color tuning of Ce3+ and Tb3+ co-doped Ca2YZr2Al3O12 phosphors with high color rendering index via energy transfer

Abstract

Originating from the precise control of the luminous color, the development of phosphors with color tunable and single-component white-emitting luminescence properties has always been the focus of high-quality white LED research. Herein, we report that a promising candidate of Ca2YZr2Al3O12: Ce3+, Tb3+ (CYZA: Ce3+, Tb3+) phosphors can be excited by near ultraviolet light (n-UV) to meet the above requirements. The Ce3+ and Tb3+ co-doped garnet-type Ca2YZr2Al3O12 with blue, cyan and green-emitting were synthesized by the conventional high temperature solid-state reaction in air atmosphere. The X-ray diffraction, photoluminescence at room temperature and variable temperature, fluorescent lifetime measurements were characterized to analyze the crystal structure, luminous performance, energy transfer mechanism and thermal stability behavior in detail. As-prepared samples displayed tunable photoluminescence based on the energy transfer from Ce3+ to Tb3+ upon n-UV excitation. More importantly, CYZA: Ce3+, Tb3+ doped with a certain amount of Eu3+ remain single-phase and possess high color rendering index up to 90. The as-fabricated WLED device shows a white light-emitting with the chromaticity point of (0.3578,0.3790) at CCT of 4673 K, which can be further improved via optimizing the ratio of sensitized and activated ions. These results suggest that it possess a great potential as high-quality luminescent materials for the design of white LEDs with excellent performance.