Continuously controllable photoconductance in freestanding BiFeO3 by the macroscopic flexoelectric effect

作者：Rui Guo, Lü You, Weinan Lin, Amr Abdelsamie, Xinyu Shu, Guowei Zhou, Shaohai Chen, Liang Liu, Xiaobing Yan, Junling Wang, Jingsheng Chen · 发表于：Nature Communications · 年份：2020 · DOI：10.1038/s41467-020-16465-5 · 被引用次数：168 · 研究领域：Multiferroics and related materials、Nonlocal and gradient elasticity in micro/nano structures、Innovative Energy Harvesting Technologies

Abstract Flexoelectricity induced by the strain gradient is attracting much attention due to its potential applications in electronic devices. Here, by combining a tunable flexoelectric effect and the ferroelectric photovoltaic effect, we demonstrate the continuous tunability of photoconductance in BiFeO3 films. The BiFeO3 film epitaxially grown on SrTiO3 is transferred to a flexible substrate by dissolving a sacrificing layer. The tunable flexoelectricity is achieved by bending the flexible substrate which induces a nonuniform lattice distortion in BiFeO3 and thus influences the inversion asymmetry of the film. Multilevel conductance is thus realized through the coupling between flexoelectric and ferroelectric photovoltaic effect in freestanding BiFeO3. The strain gradient induced multilevel photoconductance shows very good reproducibility by bending the flexible BiFeO3 device. This control strategy offers an alternative degree of freedom to tailor the physical properties of flexible devices and thus provides a compelling toolbox for flexible materials in a wide range of applications.