Data-driven discovery of high performance layered van der Waals piezoelectric NbOI<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35393426.
- Also identified by DOI 10.1038/s41467-022-29495-y and PMC identifier 8990070.
- 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
Using high-throughput first-principles calculations to search for layered van der Waals materials with the largest piezoelectric stress coefficients, we discover NbOI<sub>2</sub> to be the one among 2940 monolayers screened. The piezoelectric performance of NbOI<sub>2</sub> is independent of thickness, and its electromechanical coupling factor of near unity is a hallmark of optimal interconversion between electrical and mechanical energy. Laser scanning vibrometer studies on bulk and few-layer NbOI<sub>2</sub> crystals verify their huge piezoelectric responses, which exceed internal references such as In<sub>2</sub>Se<sub>3</sub> and CuInP<sub>2</sub>S<sub>6</sub>. Furthermore, we provide insights into the atomic origins of anti-correlated piezoelectric and ferroelectric responses in NbOX<sub>2</sub> (X = Cl, Br, I), based on bond covalency and structural distortions in these materials. Our discovery that NbOI<sub>2</sub> has the largest piezoelectric stress coefficients among 2D materials calls for the development of NbOI<sub>2</sub>-based flexible nanoscale piezoelectric devices.