Energy distribution of surface traps for elongated in the water and corona charged PTFE films

The influence of combined treatment (cyclic elongation in the water prior to charging) on positive homocharge storage and transport has been studied by thermally-stimulated surface potential relaxation measurement of PTFE films charged by corona discharge. Using experimental data and appropriate model, based on Simmons and Tan´s analysis, we determine the energy distribution of the surface traps. It has been found that the new specific group of traps appears in the surface density of localized states, as a result of treatment. Those new traps have the broad peak located at about E*_s=1,8 eV and them attempt frequency ω_s equals 9.10¹³ s ^-1. Conversely, for untreated samples we estimate the trap parameters to be about E*_s=1,2 eV and ω_s=4 10¹³ s^-1. The chemistry of the PTFE surface have been examined before and after combined treatment by means of ESCA method. The different trap distributions can be explained by surface composition changes