Dielectric Properties of Two-Dimensional Bi₂Se₃ Hexagonal Nanoplates Modified PVDF Nanocomposites

Topological insulator two-dimensional (2D) Bi 2 Se 3 hexagonal nanoplates, which are highly insulating in the bulk and have a conductive topological surface state, have been prepared via an “EG- (ethylene glycol-) sol” method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Bi 2 Se 3 /PVDF (polyvinylidene fluoride) nanocomposites with various Bi 2 Se 3 contents have been fabricated by a tape-casting method. The microstructure and dielectric performance of the Bi 2 Se 3 /PVDF nanocomposites are studied. The dielectric constant of the dense nanocomposite films keeps a relatively low value of about 16 when the Bi 2 Se 3 content is lower than 12 vol.% then suddenly increases to 36 with a critical Bi 2 Se 3 content of 13 vol.% due to the percolation effect of the large aspect ratio of the 2D Bi 2 Se 3 nanoplates. The study of the Bi 2 Se 3 /PVDF nanocomposite system is conducive to the exploration of high-performance dielectrics.