Theoretical study of chromium and nickel-related luminescence centers in molecular-sized nanodiamonds

The present work is focused on explanation and description of recently discovered chromium and nickel-related luminescence centers in molecular-sized nanodiamond (ND) particles. Chromium and silicon-nickel luminescence centers can be leading candidates for future quantum devices thanks to their room temperature operation, photostability, narrow bandwidth and short lifetime. On the other hand such nanoparticles can be used for biolabeling. Here, we used Density Functional Theory (DFT) and time-dependent DFT (TD-DFT) techniques to investigate the defects' geometrical parameters, absorption spectra, charge and spin density distribution - we show connections between chemical and optical properties of investigated defects in nanodiamond particles. By fundamental interpretation of chromium and silicon-nickel nanodiamond luminescence centers specificities we suggest appropriate technological steps towards nanodiamond future applications. (C) 2015 Elsevier B.V. All rights reserved.