Formation of organic electro-grafted films on the surface of electrically conductive or semi-conductive surfaces

An electrically conducting or semiconducting surface, comprising:

• an organic film layer, grafted on said surface, or portion of said surface, and an outer layer adhered to the organic film layer by interdigitation, wherein the organic film layer comprises the chemical structure of at least one monomer or macro-object comprising a group that can be involved in propagation chain reactions and which is precursor of said organic film layer, and a moiety of an aryldiazonium salt or its electro-reduction by-products,
• wherein the organic film layer has a thickness from 10 nm to 10 μm;
• and
• wherein the organic film layer is not homogeneous in a direction perpendicular to the surface, the organic film layer being richer in diazonium and its electro-reduction by-products close to the surface, while farther from the surface, the organic film layer is richer in polymer.