Large Electrocaloric Effect in Nanostructure-Engineered (Bi, Na)TiO3-Based Thin Films

Yunlong Sun, Zibin Chen (Corresponding Author), Hao Luo, Jun Liang, Shery L.Y. Chang, Danyang Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

1 Citation (Scopus)


Although the solid-state cooling technology based on electrocaloric response has been considered a promising refrigeration solution for microdevices, the mediocre dipolar entropy change ΔS impedes its practical applications. In this work, ΔS of a conventional ferroelectric thin film, namely, 0.94(Bi 0.5Na 0.5)TiO 3-0.06BaTiO 3(BNBT), was greatly improved through engineering the nanodomain structures. The number of zero-field polar states and saturation polarization were greatly increased concomitant with a weakened strength of polar correlation in the thin films, owing to the local stabilization of strongly tetragonally distorted nanoclusters (tetragonality of ∼1.25) by modulating the growth conditions during the thin film deposition process. Consequently, a giant ΔS value of ∼-48.5 J K -1kg -1(corresponding to ΔT = ∼27.3 K) and a wide window of operating temperature (>70 °C) were obtained near room temperature under a moderate electric field of 1330 kV cm -1. Moreover, our engineered BNBT thin film exhibits decent fatigue endurance; i.e., a substantial electrocaloric effect over a broad span of temperature can be sustained after 5 × 10 7cyclic loading of the electric field. This work provides a universal design strategy for significantly improving the close-to-room-temperature electrocaloric performance of Bi-based ferroelectric thin films without the need of compositional or architectural complexity.

Original languageEnglish
Pages (from-to)53048-53056
Number of pages9
JournalACS Applied Materials and Interfaces
Issue number47
Publication statusPublished - 30 Nov 2022


  • electrocaloric response
  • ferroelectric
  • lead-free thin films
  • solid-state refrigeration
  • super-tetragonal structures

ASJC Scopus subject areas

  • Materials Science(all)


Dive into the research topics of 'Large Electrocaloric Effect in Nanostructure-Engineered (Bi, Na)TiO3-Based Thin Films'. Together they form a unique fingerprint.

Cite this