Nanostructured SiGe:Sb solid solutions with improved thermoelectric figure of merit

Thermoelectric Si$_{0.65}$Ge$_{0.35}$Sb$_{\delta}$ materials have been fabricated by spark plasma sintering of Ge-Si-Sb powder mixtures. The electronic properties of Si$_{0.65}$Ge$_{0.35}$Sb$_{\delta}$ were found to be dependent on the uniformity of mixing of the components, which in turn is determined by the maximum heating temperature during solid-state sintering. Provided the concentration of donor Sb impurity is optimized the thermoelectric figure of merit for the investigated structures can be as high as 0.63 at 490$^{\circ}$C, the latter value is comparable with world-known analogues obtained for Si$_{1-x}$Ge$_{x}$P$_{\delta}$.