Luminescence-lifetime mapping in diamond.

This paper introduces a new technique to the study of diamonds: mapping the luminescence lifetime of optical centres. The understanding of luminescence lifetimes in diamond is briefly reviewed. Since lifetime mapping involves extended measuring times with focused laser excitation, the stability of the H3 optical centre is investigated. We show that saturation of the H3 luminescence requires excitation power densities in excess of 10 MW cm(-2). The non-radiative energy transfer time from an H3 centre to an A aggregate is found to be equal to that from N3 centres to A aggregates, at ∼3 × 10(-16)r(8) s, where there are r bond lengths between the H3 and A centres. Non-radiative energy transfer is shown to occur from the NV(-) band to the single substitutional nitrogen atoms: the single N atoms may quench luminescence as well as the A aggregates of nitrogen. In contrast, a comparison of the decays from the very similar H3 and H4 centres demonstrates that the B aggregate produces very weak quenching of the visible luminescence from diamond.