An organic light-emitting device includes a lower electrode, an upper electrode, and an organic layer disposed between the lower electrode and the upper electrode, the organic layer including a charge transport layer and a mixed layer in contact with the charge transport layer, the mixed layer including a host, a first dopant, and a charge transporting material, the first dopant including a first functional group, the charge transporting material including a second functional group, the first dopant being drawn to a charge transport layer contact surface where the mixed layer is in contact with the charge transport layer, and the charge transporting material being drawn to the mixed layer surface other than the charge transport layer contact surface. With the present invention, the concentrations of the molecules contained in the mixed layer of the light-emitting layer and the charge transport layer can be easily controlled.