[en] A thermally stimulated current technique is used to depopulate shallow electronic charge carrier traps in poly(ethylene terephthalate) films. In undoped films, a broad energy distribution of traps are populated following irradiation. By introducing a chemical dopant that acts as a deep photocarrier trap, the shallow trap population and subsequent transport of photocarriers is radically reduced. Based on results for films containing known dopant concentrations, we estimate the density and trapping parameters of the intrinsic trap states