Temperature resistant amorphous polyimides with high intrinsic permittivity for electronic applications

High–dielectric–constant (high– k ) polymers are highly desirable for high energy density capacitors and low–voltage organic thin-film transistors (OTFTs). However, conventional high– k polymers suffer from low temperature resistance or crystalline state, hampering their applications in electronic devices in general environments. Herein, by accurate monomer design and mild polycondensation, we synthesize a new polyimide (STP–PI) featuring amorphous state, intrinsic high– k , very high thermal stability, and self-standing properties. Having polar side groups and rigid twisty backbones, the STP–PI exhibits both high and stable permittivity (5.2 ∼ 6.0 from 1 MHz to 100 Hz) and excellent thermal stability ( T d5% > 450 °C and T g  > 300 °C), superior to its counterpart without the polar side group. When applied for energy storage, STP–PI delivers a discharged energy density of 3.68 J cm −3 with discharge efficiency of 84% at 350 MV m −1 even at 200 °C, which makes a record among the state–of–the–art performance of instinct polymer dielectrics. When applied in low-voltage OTFTs as the dielectric layers, the devices show a low threshold voltage of −0.30 V and mobility value of 4.03 cm 2 V −1 s −1 . The design strategy paves a way of making high– k polyimides for high temperature energy storage and electronic applications.