Tunable luminescence from Eu3+ and Ce3+ doped/co-doped color tunable Na4Ca(PO3)6 phosphors for white LEDs and solar cell applications

In recent years, the invention of white light by combining red, green and blue (RGB) phosphors with near-ultraviolet (NUV) chips has been extensively studied. In this study, a series of Na₄Ca(PO₃)₆ (NCPO) phosphors doped and co-doped with Eu³⁺, Ce³⁺ were synthesized using solid state diffusion method at 600 °C. In the present work, the phase purity, crystalline nature, particle size, elemental composition, vibrational stretching and bending, thermal stability, luminescence behavior and IV characteristics of the synthesized samples have been analyzed. Luminescent spectra of obtained sample reveal that the samples are excited under Ultraviolet (UV)/near UV light and exhibits blue, orange and red color emission. The CIE chromaticity coordinates are found in the white color region, confirming that the synthesized phosphor produces white light. In addition, the synthesized NCPO phosphor was coated with a commercial silicon solar cell and it was found that silicon-based solar cell efficiency increased around 14.04% and 13.5% under the solar simulator and direct sunlight, respectively. Present study reveals that the synthesized phosphors have a suitable ability to serve as down-converted phosphors for white LEDs and solar cell applications.