Tetrahedrite, a promising thermoelectric material composed of earth-abundant elements, has been fabricated utilizing the rapid and low energy modified polyol process. Synthesis has been demonstrated for undoped and zinc-doped tetrahedrite samples on the gram scale requiring only 1 h at 220°C. This method is capable of incorporating dopants and producing particles in the 50−200 nm size regime. For determination of bulk thermoelectric properties, powders produced by this solution-phase method were densified into pellets by spark plasma sintering. Thermopower, electrical resistivity, and thermal conductivity were obtained for temperatures ranging from 323 to 723 K. Maximum ZT values at 723 K were found to be 0.66 and 1.09 for the undoped and zinc-doped tetrahedrite samples, respectively. These values are comparable to or greater than those obtained using time and energy intensive conventional solid-state methods. Consolidated pellets fabricated using nanomaterial produced by this solution-phase method were found to have decreased thermal conductivity, increased electrical resistivity, and increased thermopower. Exceptionally low total thermal conductivity values were found (below 0.7 W m −1 K −1 for undoped tetrahedrite and 0.5 W m −1 K −1 for zinc-doped tetrahedrite), with both having lattice thermal conductivities below 0.4 W m −1 K −1. This study explores how nanostructuring and doping of tetrahedrite via a solution-phase polyol process impacts thermoelectric performance.

Copper-antimony-sulfide compounds have desirable earth-abundant compositions for application in renewable energy technologies, such as solar energy and waste heat recycling. These compounds can be synthesized by bottom-up, solution-phase techniques that...

Thermoelectric films composed of poly(diallyldimethylammonium chloride) (PDDA), graphene, poly (3,4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and double-walled carbon nanotubes (DWNT) were prepared by using layer-by-layer assembly, followed by heating in an inert atmosphere to selectively degrade film constituents to varying degrees. PEDOT:PSS was used to stabilize graphene and DWNT in water for deposition. A 20 quadlayer PDDA/PEDOT:PSSgraphene/PDDA/PEDOT:PSS-DWNT thin film heated to 425 °C for 60 min (∼20 nm thick) exhibits a simultaneous increase in electrical conductivity and Seebeck coefficient, resulting in a power factor of 168 μW m −1 K −2 , which is an order of magnitude larger than that of the unheated control. This dramatic improvement in thermoelectric performance is due to degradation of the insulating poly(diallyldimethylammonium chloride):poly(styrenesulfonate) complex within the film, while maintaining the highly ordered conductive network formed during deposition. This study reveals a simple strategy for preparing high performance organic thermoelectric materials by selectively thermally degrading the insulating material required for film deposition.