1 research outputs found
Effect of Surface Passivation on Nanodiamond Crystallinity
Diamonds
approaching the nanoscale have the potential for use as
probe materials as their optical properties can be sensitive to optical/electric
fields, mechanical stress/pressure, and the configuration of nuclear
spins. The surface of nanodiamonds impacts their optical properties
and sensing capabilities, and examining the nanodiamond surface through
X-ray absorption can give insights into molecular surface structures.
Here, quantum dot models with varying amounts of surface carbon passivation
are prepared, optimized, and compared. The loss of the diamond sp<sup>3</sup> lattice is examined by investigating the bond length and
tetrahedral character of the carbons comprising nanodiamonds for the
appearance of aromatic sp<sup>2</sup> surface domains. Electronic
transitions in the carbon K-edge region, using the energy-specific
time-dependent density functional theory method, as well as vibrational
spectra are computed from the optimized models. The surface reorganization
is shown to affect the electronic characteristics of the nanodiamond.
As a result, there is a distinct absorption peak in the carbon K-edge
region, along with stretching modes in the vibrational spectra, that
can be correlated to the nature of the surface hybridization of the
nanodiamond