The present invention relates to an organic light emitting device (OLED) for producing electroluminescence having, in order, for example, an anode, a hole transporting layer (HTL), a blocking layer, an electron transporting layer (ETL), and a cathode. In the devices of the present invention, the hole transporting layer comprises a polymeric material, which material may be emissive or may be doped with an emissive dopant. The blocking layer and the electron transporting layer are small-molecule materials. The presence of a blocking layer confines the emission of light to the polymer layer, which may be a HTL or a separate emitting layer (EL). The devices of the present invention are suitable for use in single color, multi-color and full-color, passive or active matrix OLED displays.