Direct synthesis of group IV-vacancy center-containing nanodiamonds via detonation process using aromatic compound as group IV element source

Abstract

Nanodiamonds (NDs) containing group IV-vacancy (G4V) centers—silicon-vacancy (SiV), germanium-vacancy (GeV) and tin-vacancy (SnV) centers—have shown promising potential as fluorescent markers for bioimaging and -sensing. However, the scale of fabrication has been limited to the laboratory scale. In this study, a detonation process was applied that enables practical scale fabrication of NDs for the direct synthesis of these G4V center-containing NDs (G4V-NDs). This detonation process for the direct synthesis of G4V-NDs employed explosives with the addition of dopant molecules with group IV atoms centered on tetraphenyl compounds. The successful synthesis of negatively charged SiV and GeV center-containing NDs (SiV- and GeV-NDs) was evidenced by photoluminescence (PL) spectra with zero-phonon lines (ZPLs) attributed to such color centers. However, as a result of the same strategy, NDs containing the SnV centers were not obtained in detectable concentrations in PL measurements. When the generated concentrations of SiV- and GeV-NDs synthesized under identical conditions were evaluated based on the number of data points that clear ZPLs were observed on the PL mappings, the SiV-NDs were found to be produced more predominantly than the GeV-NDs. The physics behind such results is explained by the difference in the reaction thermodynamics for each group IV atom. • Detonation process (DP) enables practical scale production of nanodiamonds (NDs). • Direct synthesis of NDs containing SiV or GeV centers was achieved by DP. • As Si or Ge sources in DP, atoms centered on tetraphenyl compounds were used. • SnV centers were not detected in NDs obtained via same scheme. • This is due to the difference in the reaction thermodynamics for each heteroatom.