Abstract: The present invention provides a compound or complex comprising at least two moieties, each moiety being comprised of two or more thiophenes fused directly to each other. Also provided is a method for the production of the compounds of the present invention, which method comprises the coupling of one fused thiophene derivative to another fused thiophene derivative.

Abstract: The present invention provides a compound or complex comprising at least two moieties, each moiety being comprised of two or more thiophenes fused directly to each other. Also provided is a method for the production of the compounds of the present invention, which method comprises the coupling of one fused thiophene derivative to another fused thiophene derivative.

Abstract: The present invention provides a compound or complex comprising at least two moieties, each moiety being comprised of two or more thiophenes fused directly to each other. Also provided is a method for the production of the compounds of the present invention, which method comprises the coupling of one fused thiophene derivative to another fused thiophene derivative.

Abstract: An electroluminescent device has at least two active semiconductive conjugated polymer light emitting layers arranged between a cathode and an anode. The layers are arranged so that at least part of at least two layers lie in an emission zone of the device.

Abstract: In an electroluminescent device which comprises a layer of a semiconductive conjugated polymer between positive and negative charge carrier injecting electrodes, a barrier layer is arranged between the layer of semiconductive conjugated polymer and the charge carrier injecting layer for negative charge carriers. The barrier layer protects the layer of semiconductive conjugated polymer from for example mobile ions released by the reactive charge carrier injecting layer. The barrier layer can in some circumstances also itself be light-emissive.

Abstract: A semiconductive conjugated copolymer comprises at least two chemically different monomer units which, when existing in their individual homopolymer forms, have different semiconductor bandgaps. The proportion of said at least two chemically different monomer units in the copolymer is selected to control the semiconductor bandgap of the copolymer so as to control the optical properties of the copolymer. The copolymer is formed in a manner enabling it to be laid down as a film without substantially affecting the luminescent characteristics of the copolymer and is stable at operational temperature.The semiconductor bandgap may be spatially modulated so as to increase the quantum efficiency of the copolymer when excited to luminesce, to select the wavelength of radiation omitted during luminescence or to select the refractive index of the copolymer.

Abstract: An electroluminescent device is provided incorporating an emissive layer comprising a processible polymer matrix such as poly(methylmethacrylate) and a chromophoric component such as an asymmetric stilbene or distyrylbenzene. The chromophoric component is blended with the polymer matrix or covalently attached thereto as a side chain and is selected to emit radiation in the region 400 nm to 500 nm when excited to luminesce.

Abstract: A semiconductive conjugated copolymer comprises at least two chemically different monomer units which, when existing in their individual homopolymer forms, have different semiconductor bandgaps. The proportion of said at least two chemically different monomer units in the copolymer is selected to control the semiconductor bandgap of the copolymer so as to control the optical properties of the copolymer. The copolymer is formed in a manner enabling it to be laid down as a film without substantially affecting the luminescent characteristics of the copolymer and is stable at operational temperature.The semiconductor bandgap may be spatially modulated so as to increase the quantum efficiency of the copolymer when excited to luminesce, to select the wavelength of radiation emitted during luminescence or to select the refractive index of the copolymer.

Abstract: A method is provided for forming in a semiconductive conjugated polymer at least first and second legions having different optical properties. The method comprises: forming a layer of a precursor polymer and permitting the first region to come into contact with a reactant, such as an acid, and heat while permitting the second region to come into contact with a lower concentration of the reactant. The reactant affects the conversion conditions of the precursor polymer in such a way as to control the optical properties of at least the first region so that the optical properties of the first region are different from those of the second region. The precursor polymer may comprise a poly(arylene-1, 2-ethanediyl) polymer, at least some of the ethane groups of which include a modifier group whose susceptibility to elimination is increased in the presence of the reactant.

Abstract: A semiconductive conjugated copolymer comprises at least two chemically different monomer units which, when existing in their individual homopolymer forms, have different semiconductor bandgaps. The proportion of said at least two chemically different monomer units in the copolymer is selected to control the semiconductor bandgap of the copolymer so as to control the optical properties of the copolymer. The copolymer is formed in a manner enabling it to be laid down as a film without substantially affecting the luminescent characteristics of the copolymer and is stable at operational temperature.The semiconductor bandgap may be spatially modulated so as to increase the quantum efficiency of the copolymer when excited to luminesce, to select the wavelength of radiation omitted during luminescence or to select the refractive index of the copolymer.

Abstract: A method is provided for forming in a semiconductive conjugated polymer at least first and second regions having different optical properties. The method comprises: forming a layer of a precursor polymer and permitting the first region to come into contact with a reactant, such as an acid, and heat while permitting the second region to come into contact with a lower concentration of the reactant. The reactant affects the conversion conditions of the precursor polymer in such a way as to control the optical properties of at least the first region so that the optical properties of the first region are different from those of the second region.The precursor polymer may comprise a poly(arylene-1,2-ethanediyl) polymer, at least some of the ethane groups of which include a modifier group whose susceptibility to elimination is increased in the presence of the reactant.