Thin film capacitors are widely used in smart grid

wind power generation

electric vehicle

pulse power system and other fields because of their high power density

low loss

long cycle life

safety and environmental protection. The dielectric is the key to the performance of film capacitors

but the energy storage property of film capacitors is greatly reduced by the leakage current caused by the defects and impurities in the materials at high temperature and high electric field

it is difficult to obtain high energy density in thermally and electrically coupled fields. The introduction of trace organic molecule semiconductor into polymer dielectric can produce energy traps to trap carriers and suppress leakage current

thus reducing conductivity loss and improving charge-discharge efficiency. In this paper

the methods of improving the high temperature energy storage properties of dielectrics by introducing organic molecular semiconductors into polymer matrix are reviewed

the influence mechanism of organic small molecule semiconductor and polymer molecular semiconductor modification on energy storage properties is discussed

and the future development of related fields is prospected.