The influence of trap coupling effect on the shape of optically stimulated luminescence decay

The decomposition of optically stimulated luminescence (OSL) curves into first-order components is a common practice of researchers. The first-order kinetic model can be valid for the simple energetic level set—single OSL trap and single luminescence centre, so an appearance of any additional level can produce a deformation of OSL curve. A strong deformation, which makes impossible to deconvolute the OSL curve into first-order components, informs about the incorrectness of the kinetic model assumption, but deformation, which does not lead to erroneous fitting procedure results, can be unrecognized. Two cases of basic model widening are considered—additional TL trap and additional luminescence centre. The results of simulation and curve deconvolution are presented for broad ranges of centre parameters and for different experimental conditions. The appearance of an additional recombination centre is shown as a particular source of OSL curve deformation.