Electrochemical doping for lowering contact barriers in organic field effect transistors

► The electrochemical p-doping of pentacene is reversible and stable shown by means of spectro-electrochemistry. ► Electrochemical p-doping can be directly applied to a pentacene-based transistor structure. ► Electrochemical contact doped transistors show significantly improved performances. ► A systematic analysis works out the reduction of contact barriers from the contact doping. ► The decrease of contact barriers is explained by the formation of a Mott-Schottky junction between metal and p-doped pentacene