A research team that included Molecular Foundry staff recently reported an atomic level simulation of semiconducting nanocrystals that provide a new understanding of the precise atomic structure at their surfaces.
Significance and Impact
Understanding the precise atomic structure at the surface is key to controlling nanocrystal shape and properties.
- PbS nanocrystals have an excess of lead ions relative to sulfate, and oleate ligands are too big to achieve the packing density required to passivate all of the surface charge.
- Ab initio electronic structure calculations indicated that hydroxyl ions could be present between the surface-bound ligands and would lead to the passivation of the surface.
- TEM, XPS and IR spectroscopy were used to validate this theory by proving the existence of the predicted hydroxyl ions on the nanocrystal surface.