Highly-efficient cyan-emitting phosphor enabling high-color-quality lighting and transparent anticounterfeiting

Constructing the broad-band emitting luminescent materials with high quantum yield is of great significance towards their widespread applications. Herein, series of Eu2+ activated, whitlockite-type Ca8ZnY(PO4)(7) phos-phors are developed towards bifunctional platform involving the white LED and anti-counterfeiting field. Benefiting from the typical 5d-4f transitions among Eu2+ ions, the broad asymmetric cyan-emission spectra (FWHM = 78 nm) is generated under 365 nm excitation with a highest quantum yield of similar to 72.11 %. The optimal doping concentration of Eu2+ ions in the Ca8ZnY(PO4)(7) host is determined as 4 % and the concentration quenching mechanism is mainly attributed to a dipole-dipole interaction. Impressively, after exploiting the newly discovered cyan-emitting phosphors Ca8ZnY(PO4)(7):Eu2+, the CRI value of as-prepared warm w-LED de-vices is remarkably enhanced from 83.9 to 90.5. Moreover, the w-LED exhibits an applicable correlated color temperature (CCT = 4176 K) and good color stability. Additionally, the transparent anticounterfeiting film is fabricated based on the highly efficient phosphors and soluble PVA, which presents anticounterfeiting perfor-mances due to their bright cyan emission upon UV light. Notably, their sustainability, excellent flexibility and foldability provide more possibilities applied for anticounterfeiting field. These results suggest the highly effi-cient phosphors Ca8ZnY(PO4)7:Eu2+ are promising bifunctional luminescent platforms, for both high-color -quality lighting and anticounterfeiting applications.