Study of surfactant bonding to lead telluride nanoparticles

Colloidal suspensions of PbTe nanoparticles coated with oleic acid were obtained using a high-temperature solution phase method. Bonding between the oleic acid and nanoparticles was investigated using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy. The results indicated that oleic acid coordinated the nanoparticles symmetrically through carboxyl groups, and the interaction modes were bridging bidentate and chelating interactions. The strong coordination by the capping monolayer made the nanoparticles stable against oxidation. Nanocrystalline PbTe exhibited electrical conductivity, which itself had an activation character with increasing temperature.