PHENOMENON AND MECHANISM OF LONG-LASTING PHOSPHORESCENCE IN EU2-DOPEDALUMINOSILICATE GLASSES()

Eu2+-doped glasses in the SrO-Al2O3-SiO2 system show bright and long-l asting phosphorescence. After irradiation by a white-color fluorescent lamp with a power density of 2 x 10(4) lux for 30 min, a visible ligh t (peaking at 510 nm) can be clearly seen with the naked eye in the da rk even 24 h after removal of the activating light. Based on the X-ray absorption spectra, we suggest that the long-lasting phosphorescence in the Eu2+-doped glasses results from the recombination of electrons and holes at shallow traps in the glass matrix which can be thermally released at room temperature. These glasses may be promising materials for energy-saving display and useful for the improvement of the conve rsion efficiency of solar cells. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.