Spectroscopic Properties of Chalcopyrite Nanoparticles

An
approach is presented to construct stoichiometric and saturated
clusters as representative models for nanoparticles based on quantum-chemical
surface energy calculations. The procedure consists of three steps.
In the first step, the shape of the cluster is determined by applying
the Wulff theorem based on calculated surface energies of the solid
compound. Stoichiometry is recovered by adding selected atoms on the
cluster surface. If the particles in solution are to be modeled, solvent
molecules may be added. A global optimization is then performed to
allow for full reconstruction of the cluster structure. As an example,
we studied the spectroscopic properties of chalcopyrite (CuFeS2) nanoparticles and compared our calculated results to experimental
O 1s X-ray photoelectron spectroscopy, IR, and optical spectra.