Colloidal Nanocrystals with Molecular Metal Chalcogenide Surface Ligands

Colloidal Nanocrystal Compounds

Colloidal nanocrystals have properties that fall between those of the individual atoms but also differ from bulk due to confinement effects. They can thus be thought of as analogs of atoms, and, like atoms, there is a desire to bond together neighboring particles, which will also affect their properties. During synthesis, organic ligands are used to prevent the colloidal nanocrystals from growing too large or agglomerating, but these ligands result in poor interparticle coupling and communication. Kovalenko et al. (p. 1417 ) show that chalcogenide complexes (compounds based on S, Se, or Te) can effectively link together neighboring particles. Upon gentle heating, the ligands can be converted from insulating to semiconducting without altering the chemistry of the nanocrystals.