An organic light emitting device including a first electrode; a self-assembled monolayer on the first electrode; a hole control layer on the self-assembled monolayer; a light emitting layer on the hole control layer; an electron control layer on the light emitting layer; and a second electrode on the electron control layer, wherein the self-assembled monolayer includes a plurality of organic molecules, each of the plurality of organic molecules having a head bonded to the first electrode, a terminal end adjacent to the hole control layer, and a tail connecting the head with the terminal end.