Trapping Mechanism Associated with Electron Delocalization and Tunneling of CaAl[sub 2]O[sub 4]:Ce[sup 3+], A Persistent Phosphor
Open Access
- 1 January 2003
- journal article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 150 (3), H61-H65
- https://doi.org/10.1149/1.1553792
Abstract
A long afterglow phosphor, CaAl2O4:Ce3+,CaAl2O4:Ce3+, was prepared and studied. It exhibits a broad-band emission in the deep blue with a persistence time longer than 10 h. The Ce3+Ce3+ ions occupy three distinct Ca2+Ca2+ sites in this material, and the emission and excitation spectra from Ce3+Ce3+ ions in these sites have been identified. The thermoluminescence spectra were obtained following irradiation at different wavelengths. Five traps were found: two of the traps, with depths of 0.67 and 0.82 eV, are filled by electron transport though the conduction band; the other three, with depths of 0.4, 0.46, and 0.6 eV, are filled by electrons tunneling from the 5d levels of adjacent Ce3+Ce3+ ions. Photoconductivity measurements were also made which indicated that the lowest 5d levels of Ce3+Ce3+ lie below the conduction band and that the ground state of Ce3+Ce3+ is about 1.1-1.4 eV above the valence band of the host. © 2003 The Electrochemical Society. All rights reserved.This publication has 15 references indexed in Scilit:
- Trapping processes in CaS:Eu2+,Tm3+Journal of Applied Physics, 2000
- Excited state impurity band conductivity in Y2(SiO4)O:Ce3+Journal of Luminescence, 1999
- Photoconductivity and delocalization in rare earth activated insulatorsJournal of Luminescence, 1999
- Long lasting phosphorescence and photostimulated luminescence in Tb-ion-activated reduced calcium aluminate glassesJournal of Applied Physics, 1999
- Crystal growth and characterization of Eu2+, Dy3+:SrAl2O4 and Eu2+, Nd3+:CaAl2O4 by the LHPG methodJournal of Crystal Growth, 1999
- Luminescence and Photoconductivity of Cerium CompoundsActa Physica Polonica A, 1996
- A New Long Phosphorescent Phosphor with High Brightness, SrAl2 O 4 : Eu2 + , Dy3 +Journal of the Electrochemical Society, 1996
- Excited-state absorption of-doped materialsPhysical Review B, 1993
- Optical-absorption and photoionization measurements from the excited states of :Physical Review B, 1989
- Zur kristallstruktur von CaAl2O4Journal of Inorganic and Nuclear Chemistry, 1976