The presence of isolated defects in the lattice of large band-gap semiconductors can introduce colored centers, by altering their electronic properties giving rise to transitions within the visible region. Diamond has a rigid and dense lattice preventing defect diffusion and phase transitions under high pressure and temperature settings. Upon approaching the nanoscale doped diamonds can be used for applications such as quantum computing, sensing, and cryptography, and as such much interest has been garnered to make and characterize these systems. Investigation of the rearrangement of the surfaces of the nanodiamond, including the effects on the X-ray absorption spectrum, have been theoretically investigated, and the contributions of the surface rearrangement to previously debated pre-edge features has been shown.
In addition, we developed a versatile method to dope diamond for quantum applications by first synthesizing a doped, nanostructured amorphous carbon precursor and then transforming it to nanodiamond at high pressure, high temperature conditions. Specifically, we incorporated silicon atoms in the form of the split silicon vacancy color center. The origin of the pressure dependence of this site as well as X-ray and vibrational signatures of the negatively charged silicon split vacancy were investigated experimentally and computationally.