Thermoluminescence properties of SiO2 : Al, Eu

SiO2 crystals have been used in lasers, fiber amplifiers, electroluminescen ce devices and thermoluminescence (TL) dosimeters. However, the emission me chanism of TL has not yet been clearly explained. Recently, it has become p ossible to obtain amorphous, highly pure, SiO2 prepared by the sol-gel meth od. The emission mechanism of TL was investigated using SiO2 samples doped with Al and/or Eu. Two glow peaks were observed on Al,Eu-codoped samples an d Eu-doped samples, but a weak glow peak was done on A-doped samples. In Al ,Eu-codoped samples, the TL spectra contained TL spectra of both Al-doped a nd Eu-doped samples. These results indicate that Al or Eu substitutes for S i and plays the role of a hole trap and/or electron trap, which contributes to the TL phenomenon. In addition, the trap depth was evaluated from two T L glow peaks (ca. 0.5 and 2 eV). From these results, the emission mechanism of TL was obtained. (C) 2000 Elsevier Science S.A. All rights reserved.