Achieving a high energy storage density in Ag(Nb,Ta)O ₃ antiferroelectric films via nanograin engineering

Abstract

Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization (P max ) and a small remnant polarization (P r ), AgNbO 3 -based antiferroelectrics (AFEs) have attracted extensive research interest for electric energy storage applications. However, a low dielectric breakdown field (E b ) limits an energy density and its further development. In this work, a highly efficient method was proposed to fabricate high-energy-density Ag(Nb,Ta)O 3 capacitor films on Si substrates, using a two-step process combining radio frequency (RF)-magnetron sputtering at 450 ℃ and post-deposition rapid thermal annealing (RTA). The RTA process at 700 ℃ led to sufficient crystallization of nanograins in the film, hindering their lateral growth by employing short annealing time of 5 min. The obtained Ag(Nb,Ta)O 3 films showed an average grain size (D) of ~14 nm (obtained by Debye-Scherrer formula) and a slender room temperature (RT) polarization-electric field (P-E) loop (P r ≈ 3.8 C•cm −2 and P max ≈ 38 C•cm −2 under an electric field of ~3.3 MV•cm −1 ), the P-E loop corresponding to a high recoverable energy density (W rec ) of ~46.4 J•cm −3 and an energy efficiency (η) of ~80.3%. Additionally, by analyzing temperature-dependent dielectric property of the film, a significant downshift of the diffused phase transition temperature (T M2-M3 ) was revealed, which indicated the existence of a stable relaxor-like † Hongbo Cheng and Xiao Zhai contributed equally to this work.

Van der Waals Epitaxy Enables Rollable Dielectric Superlattice for Record High Overall Energy Density

“…Note that the near-zero remanent polarization of relaxor antiferroelectric makes it different from relaxor ferroelectric. [24,25] Combing these two strategies together, we anticipate record high overall energy density for oxide dielectrics that is largely compatible with scale-up manufacturing of polymeric capacitors.…”

Improved energy storage performance in flexible (PbLa)ZrO3 thin films via nanocrystalline engineering

“…According to relevant results, low R rms is beneficial to improving the insulation performance of the films. [31][32][33] To further investigate the dielectric properties of (PbLa)ZrO 3 thin films at different annealing temperatures, the temperature dependence of dielectric loss (tan d) and dielectric constant (e r ) is shown in Fig. 4.…”

“…6(e). 22,32,33,[35][36][37][38][39][40] (PbLa)ZrO 3 films exhibit excellent energy storage performance by designing nanocrystalline microstructures. With excellent W rec and Z, as well as a high E b , our results have promising prospects in the field of highperformance dielectric capacitors.…”

“…According to relevant results, low R rms is beneficial to improving the insulation performance of the films. 31–33…”

Dielectric, pyroelectric, and ferroelectric studies in (1 − x)AgNbO3–xFeNbO4 lead-free ceramics

“…28 Most research is focused on the application of this material in the field of energy storage because of its double hysteresis loops, but some research is related to an improvement in the catalytic properties of this material. [32][33][34][35][36] In recent years, only Li et al 37 have studied the pyroelectric effect of this material and obtained a large p-value at room temperature (0.368 nC cm −2 K −1 ) for 0.95AgNbO 3 -0.05LiTaO 3 . They also reported a high pyroelectric energy density of 1.4 J cm −3 for 0.5AgNbO 3 -0.5LiTaO 3 ceramics.…”