Visualization of trap distribution in SrAl2O4:Eu2+,Dy3+ revealed by simulations of luminescence changes in charging and emission of persistent luminescence and thermoluminescence based on a random walk model

Abstract

A stochastic analysis of the change in persistent luminescence (PersL) of Sr_0.9Al₂O₄:Eu_0.01x²⁺,Dy_{(0.1−0.01x)}³⁺ (SAOED_x, x = 2, 4, 5, 6, 8, and 10) based on a one-dimensional random walk model (1D RWM) is presented. In the RWM, the excited electron is treated as a particle and can hop stochastically between reservoirs aligned in a straight line. Simulations of changes in PersL and the charging process are performed to determine the hopping probabilities and the electron distributions in reservoirs. We predict potential energies of the electron reservoirs through simulations of the thermoluminescence (TL) spectra of SAOED_x and present potential energy diagrams of the luminescence center and traps involved in PersL.