Achieving Enhanced Cool White Light from Combustion Derived Dy³⁺Activated Ca₉Y(PO₄)₇ Nanophosphors for Commercial Lighting Applications

The ongoing ambitious progression in the illumination sector to design the iconic WLEDs has bestowed an impetus to manufacture novel and eco-friendly nanophosphors (NPs). In this pursuit, we have presented cool white light-emitting single-phase crystalline Dy³⁺ -doped Ca₉Y(PO₄)₇ i.e., CYP:Dy³⁺ nanophosphors synthesized via a facile, economical, and non-toxic solution combustion (SC) technique. The crystal structural details regarding phase formation and crystallite size of CYP:Dy³⁺ was inferred using powder x-ray diffraction (PXRD), which suggests the structures are in a rhombohedral phase with the R3c space group. The Kubelka–Munk model was used to evaluate the optical band gap of 4.18 eV, thus revealing their desired optical quality and semiconductor nature. Transmission electron microscopy (TEM) showed agglomerated particles with irregular dimensions with an average size ranging from 40 nm to 65 nm. Photoluminescence studies indicated the emission of visible photons under high energy irradiation with the bands at ⁴F_9/2 → ⁶H_{13/2, 15/2}, due to intra-configurational transitions of Dy³⁺ ions. The phosphor was located in the white region with the Commission Internationale de I'Eclairage (CIE) chroma coordinates of (0.295, 0.336). Thus, the presented work carves an avenue for the synthesis of single-phase nanophosphors with economical and environmental advantages, along with a proposal to boost the advancement in WLEDs relevant to industrial prospects, thus generating more revenue.