Multifunctional poly(vinylidene fluoride–co‐hexafluoropropylene) ‐ zinc stannate nanocomposite for high energy density capacitors and piezo‐phototronic switching

Abstract

AbstractElectroactive multifunctional nanocomposite films of poly(vinylidene fluoride – co ‐ hexafluoropropylene) (P(VDF‐HFP)) and different zinc stannate (ZnSnO3) filler concentrations were processed by hot pressing to achieve multilayer structure formation. A notable increase in the dielectric constant (K ≈ 30 at 1 kHz) was achieved in the three‐layered hot‐pressed composite film. The resultant relaxation time, that is, the time required to reach the remnant polarization (Pr) from saturation polarization (Ps) of hot‐pressed films reduced to 1/20th time to that of its single‐layer film. Furthermore, ferroelectric loop data of hot‐pressed structure shows the lower value of remnant polarization (0.20 μC/cm2) as compared to nanocomposite film (0.28 μC/cm2) under similar measurement conditions, which further leads to an increase in energy density (2900 mJ/cm3 at 250 MV/m vs 500 mJ/cm3 at 150 MV/m). The study shows the dependency of energy storage and remnant polarization on the relaxation time of dielectric that can be further explored to enhance the energy density of dielectric capacitors. Thereafter, the multifunctional nature of nanocomposite film is shown by coupling semiconducting, light and piezoelectric effects in piezo‐phototronic switching under tensile and compressive strain in dark and light conditions.