Ultrafast emission of nanodiamond powder

The ultrafast emission of nanodiamond powder has been detected with ultrafast fluorescence spectroscopy. The ultrafast emission spectrum has been deconvoluted by the Monte-Carlo method and the results show 2 fast decays as 60ps and 350ps, with weighting about 80 percent and 20 percent of the whole emission intensity respectively. Such fast emission has not been detected under the same experimental condition for the samples of pure and defected bulk diamonds. The reason for such ultrafast process has been discussed.