Investigation on fluorescence and thermoluminescence of bismuth silicate crystal doped with Dy

Abstract

Bismuth silicate single crystals doped with rare-earth dysprosium (Dy) were excited by ultra-violet laser pulses with pulse width of 100ps and wavelength of 266nm, the lifetime and spectra of the fluorescence were observed. After the samples were irradiated at liquid nitrogen temperature, the thermoluminescence was measured at the rate of 1K/s. Fluorescence experiments show that the lifetime of the slow decay component is about 100ns, and the fast decay component is weak; The incorporation of a small amount of Dy can enhance the fluorescent intensity, and so do to the lifetime of slow decay component of the fluorescence; the fluorescence intensity and lifetime decrease while the doping concentration is too large. Low temperature thermoluminescence measurements show that there are thermoluminescence peaks near 176K and 230K, and the corresponding energies of thermoluminescence traps are 0.27eV and 0.36eV. The presence of these shallow traps may attenuate the fast decay components of the crystal's fluorescence.