HIGH-ELECTRIC-FIELD ELECTROLUMINESCENCE IN HYDROGENATED AMORPHOUS-SILICON CARBIDE ALLOYS

High electric field effects in hydrogenated amorphous silicon carbide alloys have been investigated employing a double insulating ac-driven electroluminescent device structure. The carbon content was systematic ally changed by deposition conditions. Two distinguished high electric fields effects, namely, hot-electron induced electroluminescence tail ing into above-gap spectral domain and avalanche multiplication indica ted from saturation of the electric field were found at the electric f ield strength of about 1.4-2.3 MV/cm in amorphous silicon carbide as t he effects in hydrogenated amorphous silicon. From an analysis of the decay of the emission spectrum in terms of the lucky-drift model. the electron mean free path can be estimated: the mean free path tends to be reduced with an increase of the optical energy gap, which implies i t would be reduced with an increase of structural disorder due to carb on alloying as in lower electric field.