A circuit model for SECCM and topographic imaging method in AC mode.

Area of Science:

• Electrochemistry
• Surface Science
• Microscopy

Background:

• Single-barrel scanning electrochemical cell microscopy (SECCM) enables simultaneous electrochemical activity analysis and sample surface imaging.
• A key advantage of SECCM is avoiding sample immersion in solution, preventing unwanted electrolyte-sample reactions.
• Traditional DC topographic imaging in SECCM relies on redox current to determine Z-height, but suffers from low signal-to-noise and dependence on droplet size and scanning speed.

Purpose of the Study:

• To propose and validate a single-barrel SECCM circuit model for DC mode.
• To introduce and evaluate an AC scanning mode for improved SECCM topographic imaging.
• To address limitations of DC mode, including susceptibility to interference and dependence on physical scanning parameters.

Main Methods:

• Development of a single-barrel SECCM circuit model.
• Experimental verification of the circuit model using first-order zero-state response in DC mode.
• Implementation and testing of a novel AC scanning mode utilizing AC amplitude changes for Z-height determination.

Main Results:

• The proposed circuit model for SECCM was successfully validated in DC mode.
• The AC scanning mode demonstrated a robust ability to overcome environmental interference.
• High-stability topographic imaging was achieved using the AC scanning mode.

Conclusions:

• The AC scanning mode offers a significant improvement over traditional DC methods for SECCM topographic imaging.
• The developed SECCM circuit model provides a foundation for understanding and optimizing SECCM operations.
• SECCM, particularly with the novel AC mode, presents a powerful tool for simultaneous electrochemical and topographic surface analysis without sample immersion.