Ultrahigh piezoelectricity by polaron-defect complexes.

Polaron-defect complexes in K-doped AgNbO3 thin films achieve an ultrahigh piezoelectric coefficient of ~7170 pm/V at kilohertz frequencies.

• Why it matters: This breakthrough addresses the longstanding trade-off between response speed and polarization magnitude in ferroelectric materials, enabling faster electromechanical applications.
• What they did: The researchers engineered 8 mol% K-doped AgNbO3 thin films to host reconfigurable polaron-defect complexes, utilizing electro-elastic interactions to facilitate rapid polaron hopping and defect polarization.
• The result: This approach results in giant, fast piezoelectric responses, with strain reaching ~6.2% at kilohertz frequencies, opening new possibilities for high-speed, high-performance electromechanical devices.