Enhanced thermoelectricity by controlled local structure in bismuth-chalcogenides

Revisiting some chalcogenides for thermoelectricity.

Thermoelectric materials that are efficient well above ambient temperature are needed to convert waste-heat into electricity. Many thermoelectric oxides were investigated for this purpose, but their power factor (PF) values were too small (∼10-4 W m-1 K-2) to yield a satisfactory figure of merit zT. Changing the anions from O2- to S2- and then to Se2- is a way to increase the covalency. In this...

Spin-flip Enhanced Thermoelectricity in Superconductor-Ferromagnet Bilayers

We study the effects of Zeeman-splitting and spin-flip scattering in a superconductor (S) on the thermoelectric properties of a tunneling contact to a metallic ferromagnet (F) using the Green’s function method. A giant thermopower has been theoretically predicted and experimentally observed in such structures. This huge thermoelectric effect is attributed to the spin-dependent particle-hole asy...

Phase transition enhanced thermoelectric figure-of-merit in copper chalcogenides

Entropically stabilized local dipole formation in lead chalcogenides.

We report the observation of local structural dipoles that emerge from an undistorted ground state on warming, in contrast to conventional structural phase transitions in which distortions emerge on cooling. Using experimental and theoretical probes of the local structure, we demonstrate this behavior in binary lead chalcogenides, which were believed to adopt the ideal, undistorted rock-salt st...

An Adsorption Chiller Driven by Thermoelectricity