An organic light-emitting device comprises an anode; a cathode; a charge transporting layer comprising a charge-transporting material doped with a light-emitting dopant between the anode and the cathode; and a light-emitting layer between the anode and the cathode. The x- coordinate value and / or the y-coordinate value of ClE(x,y) coordinates of light emitted from the device is no more than 0.1, and preferably no more than 0.05, from the respective x- or y- coordinate value of a control device in which the charge transporting layer is not doped with a light-emitting dopant. The light emitting layer and charge transport material preferably comprise polymers including aryl or heteroaryl repeat units.