Tuning charge transport across junctions of ferrocene-containing polymer brushes on ITO by controlling the brush thickness and the tether lengths

•We fabricated junctions with ferrocene-containing polymer brushes between two electrodes.•Conduction mechanism of the junctions can be switched from tunnelling to hopping.•The direction of rectification can be controlled via the polymer brush thickness.•Redox-active polymer brushes are interesting for nanoscale electronics.