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Nanocrystal Simulation Verified by the Discovery of Predicted Hydroxyl Ions
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.
D. Zherebetskyy, M. Scheele, Y. Zhang, N. Bronstein, C. Thompson, D. Britt, M. Salmeron, P. Alivisatos, & L.-W. Wang. Science 2014 [epub ahead of print].