| abstract |
An electroluminescent device comprises first and second layers (6, 12) of light emitting semiconductive conjugated polymers with an electrode arrangement (4, 8, 10, 14) for injecting charge carriers into both light emissive layers to cause light to be emitted therefrom. The first and second light emitting layers are in viewing overlap and the electrode arrangement comprises two sets of electrodes (4, 8; 10, 12) which can be operated independently. The first light emissive layer is arranged to emit radiation of a first wavelength when excited and the second light emissive layer is arranged to emit radiation of a second wavelength when excited. The electroluminescent device can thus be operated to cause either radiation of the first wavelength or radiation of the second wavelength or both to be emitted and viewed. |