Electroluminescent devices having a light-emitting layer

摘要

PCT No. PCT/GB94/01840 Sec. 371 Date Apr. 22, 1996 Sec. 102(e) Date Apr. 22, 1996 PCT Filed Aug. 23, 1994 PCT Pub. No. WO95/06400 PCT Pub. Date Mar. 2, 1995An electroluminescent device includes 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 includes 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.