(325a) Quantification of Ligand-Shell Structure on Colloidal PbS Quantum Dots

Continued advancement in the rational design of nanocrystal superstructures requires an exquisite description of the stabilizing ligand shell’s structure and role. Using Small Angle Neutron Scattering (SANS) and GPU-accelerated coarse-grained molecular dynamics (MD) simulations, we studied the solvent penetration and local ligand structure of monodisperse colloidal PbS quantum dots. A modified core-shell form factor is proposed, capturing the faceted quantum dot shape and solvent penetration. The analogous scattering length density profile fits simulation data well and predicts the observed scattering intensity profile. Experimental data is consistent with a synthesis-specific chloride ion presence near the inorganic core as well as ligand folding over the core surface. These results validate MD simulation as an accurate tool to probe experimentally difficult-to-access ligand conditions, applicable to varying ligand length, identity, and coverage.