Synthesis of novel Dy³⁺ activated Ba₂ CaZn₂ Si₆ O₁₇ phosphors for white light-emitting diodes

Dysprosium ion (Dy³⁺ ) activated Ba₂ CaZn₂ Si₆ O₁₇ phosphors were synthesized using high temperature solid-state reaction method. Powder X-ray diffraction (PXRD) analysis confirmed the phase formation of the as-prepared phosphors. Scanning electron microscopy (SEM) analysis disclosed an agglomeration of particles with an irregular morphology. Under 350 nm excitation, the emission spectrum of Dy³⁺ ions showed bands at 481 nm (blue), 577 nm (yellow) and 674 nm (red). The influence of the Dy³⁺ concentration on its emission intensity was investigated. The optimum concentration of Dy³⁺ ions in the Ba₂ CaZn₂ Si₆ O₁₇ :Dy³⁺ phosphors were found to be x = 0.06. The critical energy transfer distance was calculated. The fluorescence lifetime was also determined for Ba₂ CaZn₂ Si₆ O₁₇ :0.06Dy³⁺ . The Commission International deI'Eclairage (CIE) chromaticity coordinates of the phosphor were calculated to be x = 0.304, y = 0.382. The activation energy for the thermal quenching was calculated to be 0.168 eV. These results indicated that the Ba₂ CaZn₂ Si₆ O₁₇ :Dy³⁺ phosphor might be a potential candidate for near ultraviolet (NUV)-based white light-emitting diodes.