Solid-state and polyol microwave synthesis of bulk and nanocrystalline group 15 chalcogenides

CHED 1243

Christine Mastrovito, Mastrovitoc@duq.edu and Jennifer A. Aitken. Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave, Mellon Hall 301, Pittsburgh, PA 15282
Group 15 chalcogenides, such as Bi2Te3 based alloys, are the best thermoelectric materials currently used; however, the thermoelectric figure of merit for these materials can be increased. It is believed that quantum confinement effects in nanostructured materials can improve the thermoelectric efficiencies. Additionally, semiconductor nanoparticles can exhibit variable and controllable properties. In this research, phase-pure bulk group 15 chalcogenides, Sb2Se3, Sb2Te3, Bi2Se3, and Bi2Te3, have been made via solid-state microwave synthesis for the first time. In addition, the microwave polyol synthetic method is being used to prepare nanoparticulate group 15 chalcogenides. In this procedure, the solvent undergoes profound overheating and reduces the metal to its zero oxidation state. These metallic particles strongly absorb microwave radiation, which enhances the reduction of the chalcogen atoms. A comparison of the bulk materials to those in the nanoparticulate form will be presented. Powder X-ray diffraction, UV-Visible spectroscopy, and electron microscopy data of these materials will be presented.