A light active device includes a semiconductor particulate dispersed
within a carrier material. A first contact layer is provided so that on
application of an electric field charge carriers having a polarity are
injected into the semiconductor particulate through the conductive
carrier material. A second contact layer is provided so that on
application of the electric field to the second contact layer charge
carriers having an opposite polarity are injected into the semiconductor
particulate through the conductive carrier material. The semiconductor
particulate comprises at least one of an organic and an inorganic
semiconductor. The semiconductor particulate may comprise an organic
light active particulate that includes at least one conjugated polymer.
When an electric field is applied between the first and second contact
layers to the semiconductor particulate through the conductive carrier
material, the second contact layer becomes positive relative to the first
contact layer and charge carriers of opposite polarity are injected into
the semiconductor particulate. The opposite polarity charge carriers
combine to form in the conjugated polymer charge carrier pairs which
decay radiatively so that radiation is emitted from the conjugated
polymer. In this case, the inventive light active device acts as a light
emitting diode.