The Joint Measurements Of Electroluminescence And Photoluminescence Of PET Films Under Low Temperature

Poly (ethylene terephthalate)-PET is used widely in electroinsulating material. As a kind of polymer insulating materials, if it's used under high voltage and stress for a long time, its ability of insulation will disappear because of breakdown for many reasons.Electroluminescence-EL is a phenomena that directly converts electricity into luminous energy, which is closely connected the space charge. The analysis of EL is believed to be an effective way of comprehending charge injection and transmission. It can be used to analyse the characters of electricity and photology as well as the detection for insulation aging. Photoluminescence-PL is a phenomena which is caused by the optical excitation of luminophor. It is not commonly to be used to study the struction of the polymer. It has important implications for understanding the structure and performent of PET by the joint measurements of Electroluminescence and Photoluminescence of PET films under low temperature.In this paper, the joint measurements of Electroluminescence and Photoluminescence of PET films under low temperature were detected. And the breakdown field was compared with the one which was tested under nomal temperature. The result shows that there are emission peaks at about 350~450nm, 500~600nm and 750nm in the EL spectrum of the PET films. The EL intensity increases along with the applied electric field when it becomes more than 2.4MV/cm. If the applied electric field is greater than 3.3MV/cm, the EL intensity will increase quickly. And keep on increasing voltage, the PET appears the phenomenon of breakdown. And there is no significant change for the threshold value that compares with 3.5MV/cm which was tested under normal temperature. The result states that the low temperature has little effect on the pre-breakdown field.