A method of fabricating an electronic device, such as an organic thin film transistor, is disclosed. A substrate, for example a silicate glass substrate, has a surface which supports at least one metallic electrode comprising at least one metal, for example gold, and at least a portion of the surface of the substrate is exposed. The method comprises selectively forming a self-assembled layer on the exposed portion of the substrate surface such that no self-assembled layer is formed on the at least one metallic electrode and applying a solution or other liquid which is repelled by the self-assembled layer to at least one metal electrode so as to selectively form a layer of further material, such as a charge injection promoting material, on the at least one metallic electrode.