Defect-engineered lead-free ultrathin ferroelectrics

September 24, 2026

In a study published in Nano Letters, authors tuned laser fluence in PLD to create Na deficiency and clustered defect complexes in NaNbO3 films, which produced deep traps that cut leakage and enabled 9 nm, sub100 mV switching.

Defect-engineered lead-free ultrathin ferroelectrics image — (left) reciprocal space map near the 002 reflection for 80 nm NaNbO3 / SrTiO3 heterostructures, showing the evolution of coexisting phase as a function of laser fluence. (right) Schematic showing the evolution of defect states with laser fluence: from isolated Na vacancies acting as shallow trap states at low fluence to NbNa−4V′Na defect complexes acting as deep trap states at high fluence.

Scientific Achievement

Researchers showed that fluence‑controlled alkali nonstoichiometry generated clustered defect complexes that produced deep traps, reduced leakage by ~5 orders of magnitude, and enabled ferroelectric switching in NaNbO3 down to 9 nm at sub‑100 mV.

Significance and Impact

This strategy enables lead‑free, ultrathin ferroelectrics to operate at ultra‑low voltages with substantially reduced leakage, presenting a transferable pathway toward efficient, nonvolatile microelectronics and electro‑optic devices.

Research Details

Reciprocal Space Mapping was performed at the CNM-APS Hard X-ray Nanoprobe beamline to study the phase structures of NaNbO3 under different laser fluences.

DOI: 10.1021/acs.nanolett.6c01514

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