Tb3+-doped CaAl2O4 samples were prepared and studied. The D-5(3,4) to F-7(J) (J = 6, 5, 4,...) afterglow emissions of Tb3+ with a persistence time of 1 h are observed. Photoconductivity experiment determined that the ground state of Tb3+ is 0.4 eV above the top of the CaAl2O4 valence band. Two thermoluminescence peaks (-3 and 114 degreesC) and two thermal stimulated current peaks (-5 and 119 degreesC) were also detected. The results indicated that the traps at -3 degreesC (1.08 eV) are close to Tb3+ emission centers, while the traps at 114 degreesC (0.66 eV) are far away from the centers. (C) 2002 Elsevier Science B.V. All rights reserved.