Realizing a 14% single-leg thermoelectric efficiency in GeTe alloys

GeTe alloys have recently attracted wide attention as efficient thermoelectrics. In this work, a single-leg thermoelectric device with a conversion efficiency as high as 14% under a temperature gradient of 440 K was fabricated on the basis of GeTe-Cu2Te-PbSe alloys, which show a peak thermoelectric figure of merit (zT) > 2.5 and an average zT of 1.8 within working temperatures. The high performance of the material is electronically attributed to the carrier concentration optimization and thermally due to the strengthened phonon scattering, the effects of which all originate from the defects in the alloys. A design of Ag/SnTe/GeTe contact successfully enables both a prevention of chemical diffusion and an interfacial contact resistivity of 8 microhm.cm(2) for the realization of highly efficient devices with a good service stability/durability. Not only the material's high performance but also the device's high efficiency demonstrated the extraordinariness of GeTe alloys for efficient thermoelectric waste-heat recovery.

Automated summary

GeTe alloys have shown high conversion efficiency and thermoelectric performance, with good stability and durability within the working temperature range. By optimizing the carrier concentration and phonon scattering effects of the material, GeTe alloys achieve efficient thermoelectric device design.