Preparation and photoluminescence characterization of novel red emitting Ba4CaB4O10F2:xEu3+ fluorescent materials

Abstract

A series of novel borate fluoride phosphors, Ba₄CaB₄O₁₀F₂:xEu³⁺ (x = 0, 0.01, 0.04, 0.06, 0.09, 0.12, 0.14, 0.17, 0.20, 0.22, 0.25,0.28, and 0.3), were successfully synthesized using the high-temperature solid-state method. The X-ray diffraction (XRD) patterns, photoluminescence properties, thermal quenching mechanisms, quantum efficiencies, and lifetime decay curves of these phosphors were thoroughly investigated. Upon excitation at 394 nm, the synthesized phosphors exhibited strong red-light emission at 613 nm, attributed to the electric dipole ⁵D₀→⁷F₂ transition of Eu³⁺. The optimal doping concentration of phosphors was found to be 25 mol%. The quantum efficiency of the Ba₄CaB₄O₁₀F₂:0.25Eu³⁺ phosphor was measured to be 49.9 %. Simultaneously, the thermal stability measurement revealed that the light intensity of Ba₄CaB₄O₁₀F₂:0.25Eu³⁺ attained 44.5 % of its initial value at 477 K. The Commission International de L'Eclairage (CIE) chromaticity coordinates of Ba₄CaB₄O₁₀F₂:0.25Eu³⁺ were determined to be (0.6465, 0.3531) and its color purity was determined to be 96.2 %. These findings highlight the potential of the Ba₄CaB₄O₁₀F₂:0.25Eu³⁺ fluorescent material for near-UV-excited pc-WLEDs applications.