The EL intensity and the spectrum of the PET films were tested under dc high electric fields by home-made experimental set-up. The result shows that the light emissio intensity of the PET films increases along with the electric fields; the pre-breakdown field is about 4.00 MV/cm. The EL spectra have emission peaks at 300~400 nm

400~460 nm

500~600 nm and 680 nm

the peaks between 500 nm and 600 nm is higher. The peak of 680 nm increases quickly after the pre-breakdown phenomenon appears. In order to value the dielectric character of the PET films

the experimental data were analyzed by the analysis of two-parameter Weibull distribution

the life time

the cumulative failure probability of the breakdown field and the reliability equation were found out under the voltage power increased step by step at (24±1)℃. After the verification of assumption

it’s found that the experimental results submit Weibull distribution.