Synthesis and Thermolelectric Properties of Bi<sub>2</sub>Te<sub>3</sub>-GeTe Pseudo Binary System

Bi2Te3 is the best compound for thermoelectric materials around the room temperature. If the temperature range is shifted to higher side, it is useful to obtain electrical energy from waste heat source which is abundant at the temperature around 500 K. In this experiment, Bi2Te3-GeTe pseudo binary compounds were investigated to shift the temperature range. The lattice thermal conductivity was remarkably decreased at 50 or 75 mol%GeTe by synergy effect of solid solution and grain boundaries. The peak temperature of figure of merit Z for Bi2Te3-GeTe pseudo binary compounds was higher than Bi2Te3.