Correlations between ESR and photoluminescence in slightly hydrogenated silicon nitride

The electronic properties of slightly hydrogenated silicon nitride prepared by plasma-enhanced chemical vapour deposition are studied by electron spin resonance and photoluminescence. We show that the detection of the nitrogen dangling bond, after thermal annealing followed by an ultraviolet irradiation, critically depends on the composition, as has already been observed in strongly hydrogenated materials. Moreover, correlations are established between the appearance of the dangling bond and the photoluminescence efficiency, suggesting that an electronic state associated with a nitrogen dangling bond could be a radiative centre.