We measured time resolved photoluminescence of amorphous hydrogenated
carbon prepared by the chemical vapour deposition technique. Depending
on the bias voltage applied to the electrode used as the substrate ho
lder, samples show more or less intense luminescence at room temperatu
re. The decay follows a stretched exponential law with a time constant
of about 70 ps for a sample prepared under zero bias. We observe that
the decay time constant increases with increasing bias voltage. (C) 1
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