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: An electroluminescent device comprising: a first charge-carrier injecting layer for injecting positive charge carriers and a second charge-carrier injecting layer for injecting negative charge carriers, at least one of the charge-carrier injecting layers being patterned so as to comprise spaced-apart charge-injecting regions; an organic light-emitting layer located between the first and second charge-carrier injecting layers; and an unpatterned conductive polymer layer located between the organic light-emitting layer and the patterned charge-carrier injecting layer, the resistivity of the conductive polymer layer being sufficiently low to allow charge carriers to flow through it from the charge-injecting regions to generate light in the organic light-emitting layer but sufficiently high to resist lateral spreading of charge carriers beyond the charge-injecting regions.

Abstract: An organic light-emitting device wherein the cathode (4, 5) comprises a first layer (5) of a conducting material and a second layer (4) of a conductive material having a work function of at most 3.7 eV and wherein the second layer is substantially thinner than the first layer, having a thickness of at most 5 nm.

Abstract: A method for tailoring the viscosity of a conjugated polymer precursor, the method comprising synthesizing the precursor by a polymerization reaction and, during the polymerization reaction, applying a shear to the reactants of the polymerization reaction so as to define the viscosity of the precursor at a desired value.

Abstract: A light-emitting cavity device comprising: a pair of mirrors spaced apart to define a resonant cavity; a luminescent layer located in the cavity; and a control layer located in the cavity and controllable to adjust the resonance wavelength of the cavity and thereby spectrally redistribute the energy emitted by the luminescent layer.

Abstract: A light-emissive polymer device comprising: an anode; a cathode; a conjugated light-emissive polymer layer located between the anode and the cathode; and a driver for applying a voltage drive scheme between the anode and the cathode of a pattern having a relatively high voltage portion which causes the polymer layer to emit light and a relatively low voltage portion during which substantially no light is emitted by the polymer layer.

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.