The polarization switching dynamics in the Al 0.72 Sc 0.28 N capacitors was studied using a standard PUND method with square pulses (see Experimental Section and Supporting Information). Figure 2a shows the switching current curves Isw ( t) for different voltage pulse amplitudes.
It is found that the Al 0.72 Sc 0.28 N capacitors exhibit an unusually steep change in the switching time– it decreases by five orders of magnitude with a moderate increase of the applied field. This feature is caused by a significantly higher activation field value (≈126 MV cm −1) in comparison with the conventional perovskite ferroelectrics.
Nature Nanotechnology (2024) Cite this article The advancement of high-performance fast-charging materials has significantly propelled progress in electrochemical capacitors (ECs).
These results indicate that the polarization measurements in Al 1-x Sc x N capacitors could be affected by the increased leakage across the capacitors during switching due to the generation of the conducting domain walls.
Electrochemical double-layer capacitors, the main representatives of the EC family, operate through electrostatic ion adsorption into high-surface-area porous carbons, which forms an electric double layer (EDL) at the electrode–electrolyte interface 3.
PFM imaging reveals that the pristine capacitors are in the downward polarization state (Figure 1c,d ), which could be switched upward by the application of a sufficiently long negative voltage pulse (Figure 1e–j ).