Intense Photoluminescence and Mechanoluminescence of Novel BaLaAl3O7 : xEu3+ Red Nanophosphors

A series of BaLaAl₃O₇ : xEu³⁺ nanophosphors have been prepared by the high-temperature solid state reaction method. The XRD and SEM characterization results present that there exists a slight influence on the crystal structure and the average particle size of the nanophosphors while the Eu³⁺ ions are doped into the matrix. The intense and narrow red photoluminescence spectra have been measured under the ultraviolet excitation and there are two optimal Eu³⁺ concentrations of 0.8 and 12 mol %, respectively, and the intensity of the former is stronger than that of the latter. Furthermore, the mechanoluminescence phenomena with the same color are also observed when the samples are scratched with a pen. The calculated results based on the measurements of thermoluminescence spectra reveal that the total initial concentration of trapped carriers of BaLaAl₃O₇ : 12Eu³⁺ nanophosphors is larger than that of BaLaAl₃O₇ : 0.8Eu³⁺ sample, which causes the change trend of ML intensity to be opposite to that of PL intensity even though both have the same Eu³⁺ doping concentrations.