Molecular dynamics simulation of the structure of mixed ligand shells stabilizing cadmium selenide nanoparticle surfaces with different curvatures

Resumo

A full-atomic molecular dynamics simulation has been performed for a ligand shell of colloidal cadmium selenide quantum dots. Trioctylphosphine, trioctylphosphine oxide, octadecylphosphonic acid, and hexadecylamine have been used as ligands. For a mixture of the two former ligands, the effect of surface curvature on the fraction of surface ions of quantum dots bonded to ligands has been studied. It has been shown that, for particles with radii of 1.9 and 4.5 nm, every second and approximately third cadmium atom, respectively, is bonded to trioctylphosphine oxide. Partial introduction of octadecylphosphonic acid and hexadecylamine may increase the fraction of bonded surface atoms by more than two times.