Gaussian approximation of thermoluminescence (TL) peaks: A common misconception for analysis of TL of persistent luminescent materials

Whenever one over simplifies a physical phenomenon or even any concept, misconceptions are bound to occur. This seems to be true in the case of use of thermoluminescence (TL) in the study of materials by non-specialists. The fact that most semiconducting/insulating materials exhibit TL has led to many publications that ignore the basic rules of use of TL in determining the two key intrinsic trapping parameters, the trap-depth (E) and the frequency factor (s) that control the phenomenon. Manipulation of the value of E and s in a system by suitable activator and co-activator leads to the optimization for specific use of materials. In this work we discuss a common misconception that has been continuously propagated. It is the deconvolution of complex glow curves using Gaussian function and using the component of TL peaks to calculate trap depth (E) by peak shape method. This assumption is questionable and can yield parameters that are physically unrealistic. To prove our point, we consider as many as four phosphors namely ZnS:Cu+ Co2+, CaxSr1-xS:Eu, Sr2MgSi2O7;Eu2+Dy3+ and BaZrSi3O9:Eu2+.