Enhancement in the Dielectric Property of Thick Lead Zirconium Titanate Films under UV Illumination

Abstract

This work studies the effect on dielectric properties of lead zirconium titanate (Pb1.1Zr0.4Ti0.6O3 [PZT]) thick films under UV light illumination (wavelength =325 nm) for the realization of tunable capacitors. A modified sol–gel technique is utilized for the growth of polycrystalline PZT thick films on nickel substrate. The PZT films are deposited on Ni, and three different temperatures (450, 550, and 650 °C) are selected for annealing the samples in air atmosphere. Dielectric studies are performed on the optimized films, under varying intensities of UV radiation. Enhanced dielectric constant values are observed under UV illumination for the PZT films annealed at 550 and 650 °C due to generation of photocarriers and induced oxygen vacancies. An appreciable change in dielectric constant of about 75% at 1 MHz frequency is seen for the PZT film fabricated at higher annealing temperature (650 ºC) under UV illumination (intensity = 12 mW cm−2). The obtained results are encouraging for the utilization of thick PZT films in tunable capacitors.

Significantly Improved High‐Temperature Energy Storage Performance of BOPP Films by Coating Nanoscale Inorganic Layer

“…But the dielectric constant of sandwichstructured films is slightly higher than pristine BOPP films (ε r ~2.2 at 1 kHz), which gradually increases with the increase of the coating layer's dielectric constant, herein ε r of PZT > AlN > SiO 2 > BN. [32,[42][43][44] Nevertheless, the dielectric loss of sandwich-structured films is slightly higher compared to pristine BOPP films, which may be caused by the ceramic target deposition-induced broken bonds of molecular chains or generation of reactive radicals on the BOPP film's surface. As shown in Figure 2b, the dielectric parameters of the sandwichstructured films exhibit excellent thermal stability, the dielectric constant is almost unchanged and exhibits excellent thermal stability from 25 to 125 °C, where the dielectric loss slightly increases above 100 °C, mainly contributing to the thermal-induced conduction loss.…”