Distribution, Diffusion and Concentration of Defects in Colloidal Diamond

Abstract

The family of carbon nanomaterials is a rich and exciting area of research that spans materials science, engineering, physics, and chemistry; and most recently, is having an impact in biology and medicine. However, spontaneous, inefficient (reversible and irreversible) phase transformations prevail at small sizes, and most (in the absence of stable surface passivation) diamond nanomaterials are decorated with a full or partial fullerenic outer shell. Although imperfect, these hybrid sp2/sp3 core–shell particles have been shown to exhibit some useful properties, particularly when combined with other imperfections, such as functional point defects. Among the variety of point defects found in diamond nanoparticles, the GR1, N-V, H3, and N3 defects emit strong and stable luminescence in the visible range. These optical properties can be harnessed for a variety of applications, provided that the structural integrity of the host nanodiamond can be assured. This chapter reviews a number of complementary computational studies examining the stability of point defects in colloidal diamond particles as a function of the radial distribution and types of surface chemistry. This data is used to predict the relative concentrations that may be expected at different sizes.

All‐Optical Thermometry with NV and SiV Color Centers in Biocompatible Diamond Microneedles

“…[ 16 ] However, controlling the concentration and spatial distribution of functional defects in nanodiamonds is difficult task because high degree of imperfection may suppress or considerably limit the sensitivity. [ 21–23 ] It is worth noting that although perfect structure and optical properties of bulk diamonds well suit for temperature sensing, large size essentially complicates their application for the cellular and subcellular monitoring.…”

“…considerably limit the sensitivity. [21][22][23] It is worth noting that although perfect structure and optical properties of bulk diamonds well suit for temperature sensing, large size essentially complicates their application for the cellular and subcellular monitoring.…”

Does Twinning Impact Structure/Property Relationships in Diamond Nanoparticles?

“…In light of these results, the role of stacking faults and dislocations is also worthy of further work, provided the issue of stacking faults/dislocations disappearing from the particles during relaxation can be overcome. Moreover, as it is known that twins in nanodiamond can act as sinks for chemical impurities, it would be interesting to dope the twinned structures here with different distributions of known impurities and color centers 61 to see if the combination has an important impact on charge transfer. More generally, the impact of different types of surface passivation such as oxidation, hydroxylation, amination, and fluorination on the charge transfer of nanodiamonds (whether twinned or not) remains an unexplored area of research.…”

Nanodiamond surface as a photoluminescent pH sensor

“…N, Si, etc) [1], or intrinsic defects (e.g. lattice vacancies) [2,3] originating from ND synthesis [4,5] and/or post-synthesis treatment [6][7][8]. These defects form so-called color centers, which possess a strong temperature-dependent (SiV [9], GeV [10] color centers) and spin-dependent (NV color centers) photoluminescence (PL) [11], show no blinking [12] or photobleaching [13], demonstrate sensitivity to free radical formation in living cells [14][15][16] and chemical reactions at ambient conditions [17] or changes in pH environment [18].…”