Luminescence-lifetime mapping in diamond

Abstract

This paper introduces a new technique to the study of diamonds: mapping theluminescence lifetime of optical centres. The understanding of luminescence lifetimes indiamond is briefly reviewed. Since lifetime mapping involves extended measuring timeswith focused laser excitation, the stability of the H3 optical centre is investigated. We showthat saturation of the H3 luminescence requires excitation power densities in excess of10 MW cm−2. The non-radiative energy transfer time from an H3 centre to an Aaggregate is found to be equal to that from N3 centres to A aggregates, at∼3 × 10−16r8 s, wherethere are r bond lengths between the H3 and A centres. Non-radiative energy transfer is shown to occur fromthe NV− band to the single substitutional nitrogen atoms: the single N atoms may quenchluminescence as well as the A aggregates of nitrogen. In contrast, a comparison ofthe decays from the very similar H3 and H4 centres demonstrates that the Baggregate produces very weak quenching of the visible luminescence from diamond.