Zn-Sb alloys for thermoelectric power generation

β-Zn₄Sb₃ was identified as a new high performance p-type thermoelectric material (Caillat et al., 1996). A maximum dimensionless thermoelectric figure of merit ZT of about 1.3 was obtained on p-type β-Zn₄Sb₃ samples at a temperature of about 400°C. This is the highest figure of merit ever obtained at this temperature for a p-type thermoelectric material. The possibility of improving ZT values by forming Zn_4-xCd_x Sb₃ solid solutions was studied. Preliminary results obtained on alloys between Zn₄Sb₃ and Cd₄ Sb₃ are presented and show that the lattice thermal conductivity can be reduced. As a result, a maximum ZT value of 1.4 at a temperature of about 250°C was obtained for a sample with a composition Zn_3.2Cd_0.8Sb₃. Initial bonding and stability studies are presented and show that the integration of these materials into devices is possible. The efficiency of a thermoelectric generator using these new materials was calculated and the results show that significant improvements are possible compared to state-of-the-art thermoelectric materials. Some potential applications for these new thermoelectric materials are described