Abstract: An optoelectronic device comprising a photoresponsive region located between first and second electrodes such that charge carriers can move between the photoresponsive region and the first and second electrodes, the photoresponsive region comprising: a stack of alternate first and second layers, each first layer comprising a first photoresponsive material and each second layer comprising a second photoresponsive material, the first and second photoresponsive materials having different electron affinities; wherein each pair of second layers on opposite sides of a first layer contact each other via first holes defined by said first layer between said pair of second layers, and each pair of first layers on opposite sides of a second layer contact each other via second holes defined by said second layer between said pair of first layers.

Abstract: An opto-electrical device comprising an anode electrode, a cathode electrode, and an opto-electrically active region located between the electrodes, the cathode electrode including a first layer comprising a material having a work function below 3.5 eV, a second layer of a different composition from the first layer, comprising another material having a work function below 3.5 eV, the second layer being further from the opto-electrically active region than the first layer, and a third layer comprising a material having a work function above 3.5 eV, the third layer being further from the opto-electrically active region than the first layer.

Abstract: An opto-electrical device comprising an anode electrode, a cathode electrode, and an opto-electrically active region located between the electrodes, the cathode electrode including a first layer comprising a compound of a group 1 metal, group 2 metal, or a transition metal, a second layer comprising a material having a work function below 3.5 eV, and a third layer spaced from the opto-electrically active region by the first and second layers and having a work function above 3.5 eV.

Abstract: An opto-electrical device comprising an anode electrode, a cathode electrode, and an opto-electrically active region located between the electrodes, the cathode electrode including a first layer comprising a compound of a group 1 metal, group 2 metal, or a transition metal, a second layer comprising a material having a work function below 3.5 eV, and a third layer spaced from the opto-electrically active region by the first and second layers and having a work function above 3.5 eV.

Abstract: An opto-electrical device comprising an anode electrode, a cathode electrode, and an opto-electrically active region located between the electrodes, the cathode electrode including a first layer comprising a material having a work function below 3.5 eV, a second layer of a different composition from the first layer, comprising another material having a work function below 3.5 eV, the second layer being further from the opto-electrically active region than the first layer, and a third layer comprising a material having a work function above 3.5 eV, the third layer being further from the opto-electrically active region than the first layer.

Abstract: An opto-electrical device comprising an anode electrode, a cathode electrode, and an opto-electrically active region located between the electrodes, the cathode electrode including a first layer comprising a compound of a group 1, group 2 or transition metal, a second layer comprising a material having a work function below 3.5 eV, and a third layer spaced from the opto-electrically active region by the first and second layers and having a work function above 3.5 eV.

Abstract: A container for storage wherein an organic light emitting device is provided on a surface thereof or as part of a wall thereof such that light emitted from the organic light emitting device is visible from the exterior of the container.

Abstract: An organic light-emitting device having an organic light-emitting region comprising a plurality of organic light-emitting pixels; switch means each associated with a respective pixel for switching power to that pixel; and drive means for driving each switch means to cycle between a first, low power mode and a second, high power mode, at a frequency sufficient to cause light emission from the associated pixel to appeal substantially continuous, the duration of the highpower mode relative to the low power mode being variable so as to vary the average brightness of the pixel.

Abstract: A semiconductor device according to the invention is characterized by comprising a stacked structure which has a plurality of layers for providing rear barrier confinement potentials, an oblique side surface intersecting edges of the plurality of layers, at least one layer overlying the oblique side such that carriers can flow in a plane parallel to the oblique side surface, and narrowing means for causing carriers to flow over the edges of the plurality of layers, only in a direction of the oblique side surface.

Abstract: A semiconductor device according to the invention is characterized by comprising a heterostructure which comprises an active layer in which carriers can flow within a conduction channel, the heterostructure including a recessed region in which part of the conduction channel is disposed and substantially in the same plane as a pair of side gate, thereby defining a restricted conduction region of the conduction channel.

Abstract: An electroluminescent device includes a semiconductor layer (4) in the form of a thin dense polymer film comprising at least one conjugated polymer, a first contact layer (5) in contact with a first surface of the semiconductor layer, and a second contact layer (3) in contact with a second surface of the semiconductor layer. The polymer film (4) of the semiconductor layer has a sufficiently low concentration of extrinsic charge carriers that on applying an electric field between the first and second contact layers across the semiconductor layer so as to render the second contact layer positive relative to the first contact layer charge carriers are injected into the semiconductor layer and radiation is emitted from the semiconductor layer.

Abstract: An electroluminescent device comprises a semiconductor layer (4) in the form of a thin dense polymer film comprising at least one conjugated polymer, a first contact layer (5) in contact with a first surface of the semiconductor layer, and a second contact layer (3) in contact with a second surface of the semiconductor layer. The polymer firm (4) of the semiconductor layer has a sufficiently low concentration of extrinsic charge carriers that on applying an electric field between the first and second contact layers across the semiconductor layer so as to render the second contact layer positive relative to the first contact layer charge carriers are injected into the semiconductor layer and radiation is emitted from the semiconductor layer.

Abstract: A lateral injection group III-V heterostructure device having self-aligned graded contact diffusion regions of opposite conductivity types and a method of fabricating such devices are disclosed. The device includes a heterojunction formed by a higher bandgap III-V compound semiconductor formed over a lower bandgap III-V compound semiconductor. The method of the present invention allows the opposite conductivity type diffusion regions to diffuse simultaneously and penetrate the heterojunction. This results in compositional mixing of the compound semiconductor materials forming the heterojunction in the diffusion regions.

Abstract: A lateral injection group III-V heterostructure device having self-aligned graded contact diffusion regions of opposite conductivity types and a method of fabricating such devices are disclosed. The device includes a heterojunction formed by a higher bandgap III-V compound semiconductor formed over a lower bandgap III-V compound semiconductor. The method of the present invention allows the opposite conductivity type diffusion regions to diffuse simultaneously and penetrate the heterojunction. This results in compositional mixing of the compound semiconductor materials forming the heterojunction in the diffusion regions.

Abstract: This invention relates to a device for electrooptic modulation of an optical beam. The device is a laminate comprising a coherent film of a conjugated polymer having semi-conducting properties as the active component laminated with two or more layers of electrically conducting, insulating or semi-conducting materials. At least the active component in the laminate is capable of interacting with the optical beam when under the influence of an electric signal and thereby result in a modulated beam. Means are provided for (i) establishing electrical contact with one or more layers of the laminate so as to enable an electrical signal to be applied across the active component and (ii) detection of the extent of modulation of the modulated beam emerging from the active component layer.