Thermoelectric properties of nanocrystalline solid solutions of bismuth and antimony chalcogenides

The samples structure of solid solutions of p- and n-type bismuth and antimony chalcogenides obtained in the form of rods 1.6 mm in diameter by hot extrusion have been studied. These rods are found to consists of nanocrystallites 8?C60 nm in size. In p-type samples, nanocrystallites aggregated into spherical crystallites 50?C100 nm in diameter, whereas nanocrystallites in n-type samples formed disoriented fibers with a transverse cross section of several ten nanometers to several micrometers and a length of a few micrometers to several dozen micrometers. The presence of nanocrystallites of this size in the sample structure reduces the thermal conductivity of bismuth and antimony chalcogenides by 10% but barely changes their resistivity and thermoelectric power. The thermoelectric efficiencies of the p- and n-type chalcogenides are 3.27 × 10^?3 and 2.78 × 10^?3 K^?1, respectively.