Flexoelectric Domain Walls Originated from Structural Phase Transition in Epitaxial BiVO4 Films

Pao Wen Shao, Heng Jui Liu, Yuanwei Sun, Mei Wu, Ren Ci Peng, Meng Wang, Fei Xue, Xiaoxing Cheng, Lei Su, Peng Gao, Pu Yu, Long Qing Chen, Xiaoqing Pan, Yachin Ivry, Yi Chun Chen, Ying Hao Chu

Research output: Contribution to journalArticlepeer-review

Abstract

Polar domain walls in centrosymmetric ferroelastics induce inhomogeneity that is the origin of advantageous multifunctionality. In particular, polar domain walls promote charge-carrier separation and hence are promising for energy conversion applications that overcome the hurdles of the rate-limiting step in the traditional photoelectrochemical water splitting processes. Yet, while macroscopic studies investigate the materials at the device scale, the origin of this phenomenon in general and the emergence of polar domain walls during the structural phase transition in particular has remained elusive, encumbering the development of this attractive system. Here, it is demonstrated that twin domain walls arise in centrosymmetric BiVO4 films and they exhibit localized piezoelectricity. It is also shown that during the structural phase transition from the tetragonal to monoclinic, the symmetry reduction is accompanied by an emergence of strain gradient, giving rise to flexoelectric effect and the polar domain walls. These results not only expose the emergence of polar domain walls at centrosymmetric systems by means of direct observation, but they also expand the realm of potential application of ferroelastics, especially in photoelectrochemistry and local piezoelectricity.

Original languageEnglish
Article number2107540
JournalSmall
Volume18
Issue number19
DOIs
Publication statusPublished - 2022 May 12

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)

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