Triple-doped Dy3+/Tb3+/Eu3+ activated Na2Ca4(PO4)3F halo-phosphors for next-generation WLEDs and solar cell efficiency enhancement

This study reports the synthesis and characterization of Na₂Ca₄(PO₄)₃F phosphor doped with Dy³⁺, Tb³⁺, and Eu³⁺ ions were synthesized using a conventional solid-state method. The phase formation was confirmed by X-ray diffraction (XRD). Functional group analysis through Fourier transforms infrared spectroscopy (FTIR) and morphological evaluation via scanning electron microscope (SEM) and EDS revealed good crystallinity and elemental distribution. The triple-doped phosphor exhibited color-tunable emissions under near-UV excitation, covering the blue, green, yellow, and red regions, resulting in efficient white light output. Photoluminescence (PL) studies indicated effective energy transfer among the dopant ions. Additionally, the phosphor was applied as a down-conversion layer on silicon solar cells using the doctor blade technique. The coated cells showed a 16.33% improvement in efficiency compared to uncoated cells. The combined optical and photovoltaic performance highlights the potential of Na₂Ca₄(PO₄)₃F: Dy³⁺/Tb³⁺/Eu³⁺ as a multifunctional material for white light-emitting diodes and solar energy devices.