Thermoluminescence excitation spectroscopy: A versatile technique to study persistent luminescence phosphors

A versatile new facility to study photoionization processes in impurity doped compounds is presented. In this new facility monochromatic light is coupled to a thermoluminescence reader, enabling a fully automated recording of glow curves as a function of photon excitation wavelength. It provides detailed information on the mechanism of trap filling preceding persistent luminescence. The technique is first demonstrated with a study on Lu(2)SiO(5):Ce(3+) and then applied to commercial modern day double lanthanide doped SrAl(2)O(4):Eu(2+),Dy(3+), Sr(4)Al(14)O(25):Eu(2+),Dy(3+), CaAl(2)O(4):Eu(2+),Nd(3+); and to the classical ZnS:Cu(+) persistent luminescence phosphors. The presented data provide new insight into the mechanism of persistent luminescence. (C) 2011 Elsevier B.V. All rights reserved.