Enabling Polymer Single Crystal to be High Performance Dielectric

Polymer dielectrics hold great potential for electrical power applications and advanced microelectronics. Unfortunately, they exist commonly in semicrystalline form with disordered aggregating microstructures, such as amorphous regions, that limit their dielectric performances, including breakdown strength, dielectric loss, and temperature stability. Efforts to improve their performances are often hindered by the lack of understanding of the diverse dielectric properties in the complex structures of these semicrystalline polymer dielectrics (SPDs). Circumventing these gaps in knowledge by crystallizing homogeneously-ordered SPDs to remove these disorders has yielded little success to date. Here, taking a typical and widely used dielectric, polyethylene (PE) as a model, big homogeneously-ordered SPDs as lamellar single crystals are successfully crystallized and studied for their dielectric properties. We obtain high-quality PE single crystals by controlling the crystallization kinetics in a self-seeding method. Nanoscale MIM capacitors built on these crystals using a non-destructive strategy exhibit a high dielectric breakdown strength and low dielectric constant, with the measured values among the best-known for PE. By exemplifying a crystallization strategy for the ordered SPDs and elucidating the origins of their outstanding dielectric properties, this work illuminates a path for deepening the fundamental understanding and enhancing the electrical performance of SPDs.