Polyetherimide is considered to be a high-performance dielectric material for next-generation capacitors because of its excellent high-temperature resistance and dimensional stability. However

space charge accumulates inside the polymer under externally applied electric field

which affects its insulating performance

and the temperature gradient caused by internal temperature rise during long-term operation of capacitors makes the space charge and electric field distribution more complicated. Therefore

in this paper

space charge accumulation is simulated on a bipolar charge transport model based on hopping conduction for polyetherimide films

and the effects of different temperature gradient conditions on the carrier injection and migration process are investigated. The low-temperature side of the sample under the temperature gradient accumulates heterocharge and the electric field increases

while the high-temperature side accumulates homocharge and the electric field decreases. The charge density and electric field distortion are greater on the low-temperature side than on the high-temperature side. As the temperature gradient increases

the average space charge and the leakage current increase exponentially

and the electric field distortion continuously increases. With a constant temperature gradient

the space charge distribution is mainly affected by the temperature difference when the overall temperature is lower. The space charge accumulation and the electric field distortion keep increasing with increasing temperature. When the temperature is higher

the electric field distortion cannot be ignored. The heterocharge on the low-temperature side decreases

and even the accumulation of homocharge occurs

resulting in a decrease in the electric field distortion.The increase in homocharge on the high-temperature side results in a greater electric field distortion than on the low-temperature side. Average space charge at high temperatures weakens from exponential growth to linear growth with increasing temperature.The leakage current has a higher growth rate with the increase of temperature

and the conductivity of the sample is enhanced accordingly.