A novel phosphate-based phosphor for multifunctional applications realized by energy transmission and color change

Abstract

The concept of healthy lighting has led to the emergence of warm white light-emitting phosphors as a prominent research focus within the lighting industry. In this study, a series of phosphors composed of Ca₈ZnY(PO₄)₇ (CZYP) doped with Dy³⁺ and Sm³⁺ were synthesized through the high-temperature solid-state technique. The crystal structure, optical properties, and energy transfer processes of the phosphors were systematically investigated. An effective energy transfer strategy was successfully implemented, achieving a remarkable energy transfer efficiency of 41.3 % between Dy³⁺ and Sm³⁺ ions when excited at 363 nm. The 365 nm UV chip was used with the synthesized phosphor to encapsulate LEDs, resulting in a low color temperature (CCT, 3438 K) and a high color rendering index (Ra, 82.1) for warm white light emission. Additionally, the emission spectrum of the phosphor satisfied the spectral criteria necessary for chlorophyll synthesis. The anti-counterfeiting of the phosphor was further investigated, leading to a multi-color switching model characterized by intuitive visualization and straightforward identification. These results suggest that the synthesized phosphors are promising for health lighting, plant lighting, and optical anti-counterfeiting applications.