Effecting factors of the emission spectral characteristics of rare-earth strontium aluminate for anti-counterfeiting application

The rare-earth strontium aluminate phosphor with stable physical and luminescent performances is a suitable rare-earth luminescent material for spectrum-fingerprint anti-counterfeiting fiber. In order to promote further the development of variety and the improvement of anti-counterfeiting effects of spectrum-fingerprint fiber, in this research, several kinds of rare-earth strontium aluminates and spectrum-fingerprint anti-counterfeiting fiber were prepared by solid-state reaction and special spinning technique, respectively. The effects upon manufacturing elements of strontium aluminate including calcining temperature, Al/Sr ratios, the addition of H₃BO₃, Eu²⁺ and Dy³⁺ and external environmental factors of applications such as fiber-forming polymer on emission spectral characteristics were investigated systematically in the anti-counterfeiting application. The results showed that with the increase in the calcining temperature, the amounts of H₃BO₃ doping and the concentration of Eu²⁺ and Dy³⁺, the emission intensity of rare-earth strontium aluminate increased and reached to the peak at a certain point at start, and then decreased gradually beyond this point. Al/Sr molar ratios influenced not only the intensity but also the wavelength of emission. Fiber-forming polymer had little effect on the emission wavelength and the shape in the luminescence, but greatly lowered the intensity of emission.