Study of crystallographic and optoelectronic behavior of single-phase Ca₉La(VO₄)₇: Sm³⁺ nanophosphor for modern illumination sector

Sm³⁺ excited vanadate-based Ca₉La(VO₄)₇ nanocrystalline material produced by solution combustion (SC) emits strong orange-red light. Irregularly shaped nanoparticles with R3c (161) space group and trigonal symmetry with an average diameter of 51 nm were prepared. Under UV stimulation, the luminescence spectrum produces an orange-red signal at wavenumber 16447 cm⁻¹ due to the ⁴G_5/2 → ⁶H_7/2 electronic transition. The results of energy transfer are also well thought out. Diffuse reflectance measurements investigate energy band gaps of the host matrix and optimal system and a lower value of the latter confirms the existence of a better luminescence after the incorporation of Sm³⁺ ions. The maximum brightness was observed at 10.0 mol% Sm³⁺ fraction. Concentration quenching effects were also observed. The finest CIE points (0.5868, 0.4027) are in the orange-red region with a CCT value of 1715 K, finally confirming the potential of present nanophosphors in modern illumination applications.