Memristive devices based on tunable Schottky barrier are provided. In one aspect, a method of forming a memristive device includes: forming a semiconductor layer on a bottom metal electrode, wherein the semiconductor layer has workfunction-modifying molecules embedded therein; and forming a top metal electrode on the semiconductor layer, wherein the top metal electrode forms a Schottky junction with the semiconductor layer, and wherein the workfunction-modifying molecules are configured to alter a workfunction of the top metal electrode. A memristive device and a method for operating a memristive device are also provided.