Abstract: A method for forming a conjugated polymer which is doped by a dopant includes the steps of (a) adding a doping agent comprising a dopant moiety to a solution containing the conjugated polymer or a precursor thereof and, optionally, a second polymer, the dopant moiety being capable of bonding to the conjugated polymer, precursor thereof or the second polymer; (b) allowing the dopant moiety to bond to the conjugated polymer, precursor thereof or the second polymer to perform doping of the conjugated polymer, wherein the amount of doping agent added in step (a) is less than the amount required to form a fully doped conjugated polymer.

Abstract: Optical devices fabricated from solvent processible polymers suffer from susceptibility to solvents and morphological changes. A semiconductive polymer capable of luminescence in an optical device is provided. The polymer comprises a luminescent film-forming solvent processible polymer which contains cross-linking so as to increase its molar mass and to resist solvent dissolution, the cross-linking being such that the polymer retains semiconductive and luminescent properties.

Abstract: A method for forming a transistor, comprising: depositing a first material from solution in a first solvent to form a first layer of the transistor; and subsequently whilst the first material remains soluble in the first solvent, forming a second layer of the transistor by depositing over the first material a second material from /solution in a second solvent in which the first material is substantially insoluble.

Abstract: An electroluminescent device comprising: a first charge carrier injecting layer for injecting positive charge carriers; a second charge carrier injecting layer for injecting negative charge carriers; and a light-emissive layer located between the charge carrier injecting layers and comprising a mixture of: a first component for accepting positive charge carriers from the first charge carrier injecting layer; a second component for accepting negative charge carriers from the second charge carrier injecting layer; and a third, organic light-emissive component for generating light as a result of combination of charge carriers from the first and second components; at least one of the first, second and third components forming a type II semiconductor interface with another of the first, second and third components.

Abstract: A method for forming an organic or partly organic switching device, comprising depositing layers of conducting, semiconducting and/or insulating layers by solution processing and direct printing; defining microgrooves in the multilayer structure by solid state embossing; and forming a switching device inside the microgroove.

Abstract: A method for forming an integrated circuit including at least two interconnected electronic switching devices, the method comprising forming at least part of the electronic switching devices by ink-jet printing.

Abstract: A field effect transistor is provided which comprises a gate electrode, a source electrode, a drain electrode, at least one organic semiconducting layer, and a hole transport layer for transferring holes from said source and drain electrodes to said organic semiconducting layer, wherein said hole transport layer comprises a layered metal chalcogenide. Processes for depositing a thin layer of a layered metal dichalcogenide on a substrate and for producing top gate structures on a layered metal chalcogenide layer in the manufacture of field effect transistors according to the invention are also provided.

Abstract: A display device comprising a driver circuit which modulates the duty cycle of the on-state of a pixel during a frame period. Preferably the driver circuit comprises a comparator and more preferably the comparator is formed of thin film transistors constituting a differential pair and an inverter. Also provided is a method of driving a display device comprising the step of modulating the duty cycle of the on-state of a pixel during a frame period. Beneficially the display device is an organic electroluminescent active matrix display device.

Abstract: A photoresponsive material comprises molecular or polymeric semiconductors in which photogeneration of separated charge carriers proceeds substantially via an intermediate stage of a triplet exciton, where the generation of the triplet exciton may be facilitated by the presence of elements of high atomic number, and in which the generation of separated charges from the intermediate triplet excited states is facilitated by the presence of at least two semiconductive components, one of which is of high electron affinity and able to accept electrons, and the other of which is of low ionisation potential and therefore able to accept positive charge carriers, the difference between the electron affinity of the former and the ionisation potential of the latter being sufficiently low so as to allow the ionisation of a triplet exciton which is present on either of the two aforementioned semiconductive components or on a third component.