Intensity enhancement of photoluminescence in Tb³⁺ /Eu³⁺ co-doped Ca₁₄ Zn₆ Al₁₀ O₃₅ phosphor for WLEDs

This article focuses on the effect of monovalent cation doping on the optical properties of rare earth (RE = Eu³⁺ , Tb³⁺ ) co-doped Ca₁₄ Zn₆ Al₁₀ O₃₅ which has been synthesized by a low temperature combustion method. Crystalline phase of the Ca₁₄ Zn₆ Al₁₀ O₃₅ phosphor was examined and confirmed by X-ray diffraction measurement. Under near-ultraviolet light excitation Eu³⁺ -doped Ca₁₄ Zn₆ Al₁₀ O₃₅ phosphor exhibit characterization of Eu³⁺ emission bands that are located at a maximum wavelength (λ_max ) of approximately 470 nm and other peaks centred at 593 nm and 615 nm, respectively. With Tb³⁺ -doped Ca₁₄ Zn₆ Al₁₀ O₃₅ phosphor showing a green emission band centred at 544 nm under near-ultraviolet range. Furthermore, we studied the energy transfer process in Eu³⁺ /Tb³⁺ pair and enhancement in photoluminescence (PL) intensity with doping different charge compensation. Here we obtained the optimum PL emission intensity of the phosphor in broad and intense visible spectral range which may be significant for the fabrication of white light emitting diodes (WLEDs).