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

Abstract 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.