Intensity enhancement of photoluminescence in Tb /Eu co-doped Ca Zn Al O phosphor for WLEDs.

This article focuses on the effect of monovalent cation doping on the optical properties of rare earth (RE = Eu , Tb ) co-doped Ca Zn Al O which has been synthesized by a low temperature combustion method. Crystalline phase of the Ca Zn Al O phosphor was examined and confirmed by X-ray diffraction measurement. Under near-ultraviolet light excitation Eu -doped Ca Zn Al O phosphor exhibit characterization of Eu emission bands that are located at a maximum wavelength (λ ) of approximately 470 nm and other peaks centred at 593 nm and 615 nm, respectively. With Tb -doped Ca Zn Al O phosphor showing a green emission band centred at 544 nm under near-ultraviolet range. Furthermore, we studied the energy transfer process in Eu /Tb 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).