A method of manufacturing an organic light-emitting device, the method including: forming an anode; forming an intermediate layer comprising an emission layer on the anode; and forming a cathode on the intermediate layer, wherein the forming of the cathode comprises thermally depositing indium or indium oxide, with at least one of a metal or a metal oxide in plasma generated in a chamber to form a transparent conductive layer of indium oxide doped with the at least one of the metal or the metal oxide.