F. Hasan Likhi, I. Vlassiouk, A. Karim
University of Houston,
United States
Keywords: graphene, hBN, energy storage
Summary:
Next-generation power electronics are expected to push frequency, temperature, and voltage to higher levels; therefore, the fundamental mechanisms governing the properties of dielectric capacitors need elaborate understanding. To address this challenge, we investigated the dynamic polymer/2D-inorganic interfacial zone by investigating a Chemical Vapor Deposited (CVD) 2D material-embedded flexible dielectric film. This study investigates the dielectric properties of polymer composites by introducing a dynamic interlayer (DIL) formed between polymer chains and nanofillers in a comparative analysis of two distinct polymers: linear polyetherimide (PEI) and ferroelectric polyvinylidene fluoride (PVDF). Chemical vapor deposition (CVD) of hexagonal boron nitride (hBN) and graphene was employed to fabricate 2D conductive and insulating interlayers between the polymer matrices. Raman spectroscopy, scanning electron microscopy (SEM), and Raman spectroscopy and XRD techniques were used to monitor the desired 2D growth and number of layers of hBN and graphene on electropolished Cu foil. The research aims to understand how the DIL, formed due to polymer chain adsorption on the nanofiller surface, influences polarization mechanisms in polymer systems using dielectric spectroscopy. To determine the energy storage capability, we measured the dielectric breakdown strength (EBD) and calculated maximum energy density of the flexible films. Alignment-controlled insulating 2D interlayer hBN improved the energy density of polymer-based capacitor films by improving the breakdown strength by ≈150%. This work provides new insights into how nanoscale interfacial interactions govern the macroscopic dielectric properties, contributing to advancements in materials for electronic and energy storage applications.