EMISSION OF BLUE-LIGHT FROM HYDROGENATED AMORPHOUS-SILICON CARBIDE

THE development of new electroluminescent materials is of current tech nological interest for use in flat-screen full-colour displays1. For s uch applications, amorphous inorganic semiconductors appear particular ly promising, in view of the ease with which uniform films with good m echanical and electronic properties can be deposited over large areas2 . Luminescence has been reported1 in the red-green part of the spectru m from amorphous silicon carbide prepared from gas-phase mixtures of s ilane and a carbon-containing species (usually methane or ethylene). B ut it is not possible to achieve blue luminescence by this approach. H ere we show that the use of an aromatic species-xylene-as the source o f carbon during deposition results in a form of amorphous silicon carb ide that exhibits strong blue luminescence. The underlying structure o f this material seems to be an unusual combination of an inorganic sil icon carbide lattice with a substantial 'organic' pi-conjugated carbon system, the latter dominating the emission properties. Moreover, the material can be readily doped with an electron acceptor in a manner si milar to organic semiconductors3, and might therefore find application s as a conductivity- or colour-based chemical sensor.