The afterglow characteristics and trap level distribution of chromatic rare-earth luminous fiber

Abstract

The samples of luminous fiber with different colors have been prepared by adding the fiber-forming polymer PET chips as base materials and SrAl₂O₄: Eu²⁺, Dy³⁺ luminescent materials. The phase composition, afterglow decay and thermoluminescent characteristics of the fiber were measured by X-ray diffraction (XRD), with an afterglow tester and a thermoluminescent dosimeter. The results indicated that the existence of the polymer matrix lowered the efficiency of excitation and consumed the energy of emission to some extent. Accordingly, the afterglow brightness of the fiber was less than that of pure strontium aluminate phosphors when excited by the same exciting light. Transparent inorganic pigments had little impact on the afterglow decay laws. When the contrast between the hue of the pigment and the colored light of the fiber was closer, the afterglow brightness of the fiber was higher. When the excitation time was longer, the initial afterglow brightness of the fiber was higher. Increasing the excitation time did not prolong the afterglow life effectively. The transparent inorganic pigments affected the luminescent intensity of the thermoluminescent peak. The E values of white, yellow and green luminescent fiber were lower than that of blue and red luminescent fiber relatively, which basically coincided with the results of the afterglow curves.