Continuously controllable photoconductance in freestanding BiFeO<sub>3</sub> by the macroscopic flexoelectric effect.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32444607.
- Also identified by DOI 10.1038/s41467-020-16465-5 and PMC identifier 7244550.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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 BiFeO<sub>3</sub> films. The BiFeO<sub>3</sub> film epitaxially grown on SrTiO<sub>3</sub> 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 BiFeO<sub>3</sub> 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 BiFeO<sub>3</sub>. The strain gradient induced multilevel photoconductance shows very good reproducibility by bending the flexible BiFeO<sub>3</sub> 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.