An improved method to evaluate trap depth from thermoluminescence

Rare earth-doped inorganic compounds contribute mostly to the family of persistent luminescent materials due to the versatile energy levels of rare earth ions. One of the key research aims is to match the trap level stemming from the doped rare earth ion or intrinsic defects to the electronic structure of the host, and therefore thermoluminescence measurement becomes a radical technology in studying trap depth, which is one of the significant parameters that determine the properties of persistent luminescence and photostimulated luminescence. However, the results of trap depth obtained by different thermoluminescence methods are quite different so that they are not comparable. Herein, we analyzed different thermoluminescence methods, selected and improved the traditional peak position method of T_m/500 to be E = (−0.94lnβ+30.09)kT_m. Only the experimental heating rate (β) is needed additionally, but the accuracy is improved greatly in most cases. This convenient and accurate method will accelerate the discovery of novel rare earth-doped materials.