Thermo-luminescence Properties Of Re Doped Bismuth Silicate

Bismuth silicate (Bi₄Si₃O₁₂) is a scintillating material and BSO crystals have similar physical properties with BGO crystals, which are a common kind of scintillating material. And as a scintillation material, BSO crystal's decay time is faster than the BGO crystals. Besides that, the cost of raw materials of BSO powder is lower than BGO, and the BSO polycrystalline material with high-purity has great significance to the growth of BSO crystals. But the light output of BSO crystal is relatively small, now researchers try to improve the luminescence properties of BSO crystals by means of doping.We successfully prepared Eu³⁺ doped BSO powders via high-temperature solid-state method. While under the near ultraviolet excitation of 394nm, Eu³⁺ doped BSO powders showing a special luminescence phenomenon, in which the emission peak removing from 613nm to 703nm. Integrating the thermoluminescence curves of samples, we concluded that with the doping concentration increases, part of Eu³⁺ ions substituted Bi³⁺ ion positions, and some Eu³⁺ ions sat in the crystal lattice in BSO and that lead to Eu³⁺ ions' environment are serious asymmetry, so Eu³⁺ ions exhibit a special light phenomenon.In this paper, high-temperature solid-state method is used to synthesis Dy³⁺ doped BSO polycrystalline powder materials, and the crystals doped with different concentrations of BSO were grown by a traditional Bridgman method. The crystals doped with a low concentration favors having a higher light output performance, while the crystals doped with high concentration can reduce the segregation of components during the crystal growth process and improving the quality of crystals, but the crystal light output were decreased. Meanwhile, according to the thermoluminescence results of crystals, we can conclude that Dy³⁺ ions sensitize Bi³⁺ ions to improve light output. But under the increasing of Dy³⁺ ions'doping concentration, the light output of high doping crystals is lower. Because Dy³⁺ ions have competition with Bi³⁺ ions and Dy³⁺ ions also are the luminescence centers.