Up-converted ultraviolet luminescence of Er³⁺:BaGd₂ZnO₅ phosphors for healthy illumination

Abstract

Moderate level of exposure to the solar irradiation containing UV component is essential for health care. To incorporate the UV-emitting phosphors into the commercial YAG-based white light-emitting diode introduces the possibilities of healthy illumination to individuals’ daily lives. 1 mol.% Er³⁺-doped BaGd₂ZnO₅ (BGZ) particles were synthesized via sol–gel method and efficient up-converted luminescence peaked at 380 nm was detected under 480 nm excitation. The mixed phosphors with varied mass ratio of Er³⁺:BGZ and Ce³⁺:YAG particles were encapsulated to form LEDs. The study of the LEDs indicated that the introduction of BGZ component favored the enhancement of color-rendering index and the neutralization of the white light emitting. The WLED with the BGZ/YAG ratio of 8:2 was recommendable for its excellent overall white light luminous performances and UV intensity of 84.55 mW/cm². The UV illumination dose of the WLEDs with mixed YAG and BGZ was controllable by adjusting the ratio, the illumination distance and the illumination time. Er³⁺:BGZ phosphors are promising UV-emitting phosphors for healthy indoor illumination.

Keywords

Er³⁺:BaGd₂ZnO₅ / up-converted ultraviolet / LED / healthy illumination

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Higher Education Press and Springer-Verlag Berlin Heidelberg