Out-of-Plane Piezoelectricity and Ferroelectricity in Layered α-In<sub>2</sub>Se<sub>3</sub> Nanoflakes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28841328.
- Also identified by DOI 10.1021/acs.nanolett.7b02198.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Piezoelectric and ferroelectric properties in the two-dimensional (2D) limit are highly desired for nanoelectronic, electromechanical, and optoelectronic applications. Here we report the first experimental evidence of out-of-plane piezoelectricity and ferroelectricity in van der Waals layered α-In<sub>2</sub>Se<sub>3</sub> nanoflakes. The noncentrosymmetric R3m symmetry of the α-In<sub>2</sub>Se<sub>3</sub> samples is confirmed by scanning transmission electron microscopy, second-harmonic generation, and Raman spectroscopy measurements. Domains with opposite polarizations are visualized by piezo-response force microscopy. Single-point poling experiments suggest that the polarization is potentially switchable for α-In<sub>2</sub>Se<sub>3</sub> nanoflakes with thicknesses down to ∼10 nm. The piezotronic effect is demonstrated in two-terminal devices, where the Schottky barrier can be modulated by the strain-induced piezopotential. Our work on polar α-In<sub>2</sub>Se<sub>3</sub>, one of the model 2D piezoelectrics and ferroelectrics with simple crystal structures, shows its great potential in electronic and photonic applications.