Huge field-effect surface charge injection and conductance modulation in metallic thin films by electrochemical gating

► Novel polymer-gating field-effect experiments allow to reach a record induced surface charge density of 4 × 1015 charges/cm2. ► A modification of the double-step chronocoulometry method is very appropriate for the determination of the induced charge density. ► Huge resistance variations (up to 8%) are observed at room temperature in thin films of different metals (Au, Ag, Cu). ► These relative resistance variations are explained very well by a simple free-electron model that includes parallel resistive channels.