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

•This paper proposes a single-barrel Scanning electrochemical cell microscope(SECCM) circuit model and verifies this circuit model using the first-order zero-state response in DC mode.•An AC scanning mode is proposed to overcome the problem of inaccurate imaging caused by interference in the DC scanning mode.•Theoretical analysis is conducted for single-barrel SECCM in DC circuit model and AC circuit model, respectively.•The conductive copper strip groove and square boss surface structures were imaged by single-barrel SECCM that was operated in the DC hopping mode and AC hopping mode, respectively.