Light emissive device

A process for the production of an organic light emissive device, which process comprises:

• providing an anode;
• optionally forming a hole-transporting layer over the anode;
• depositing from solution over the anode or hole-transporting layer a first layer of a first electroluminescent organic material which intrinsically emits light at a first wavelength;
• depositing from solution a further layer of a second electroluminescent organic material over the layer of the first electroluminescent organic material;
• and
• providing a cathode;
• whereby an organic light emissive region is formed between the cathode and the anode which comprises a layer of blue light electroluminescent organic material and a layer of longer wavelength electroluminescent organic material, wherein the blue light electroluminescent material comprises a polymer and is not doped with an emissive dopant, and wherein the layer of longer wavelength electroluminescent organic material comprises a polymer;
• wherein the layers of blue light and longer wavelength materials are selected so that the organic light emissive region emits white light falling within a region having a CIE x coordinate equivalent to that emitted by a black body at 3000-9000K and CIE y coordinate within 0.05 of the CIE y co-ordinate of said light emitted by a black body.