Highly efficient and giant negative electrocaloric effect of a Nb and Sn co-doped lead zirconate titanate antiferroelectric film near room temperature.

Adiabatic temperature variation (Δ), coefficient of performance (COP) and electrocaloric coefficient (Δ/Δ) play important roles in evaluating the comprehensive performance of solid-state cooling technology based on the electrocaloric effect (ECE). A Nb and Sn co-doped lead zirconate titanate antiferroelectric film, PbNb(ZrSnTi)O (PNZST), shows a highly efficient and giant negative ECE. The Δ, |Δ/Δ| and COP are about -9.8 K, 0.0488 K cm kV and 35.53 at around 50 °C, respectively. The full width at half maximum of the Δ peak is about 37 °C. Phenomenological analysis indicates that the highly efficient and giant negative ECE is associated with the first-order transition that has a discontinuous polarization change with increasing temperature.