Lattice Strain Leads to High Thermoelectric Performance in Polycrystalline SnSe.

Polycrystalline SnSe materials with values comparable to those of SnSe crystals are greatly desired due to facile processing, machinability, and scale-up application. Here manipulating interatomic force by harnessing lattice strains was proposed for achieving significantly reduced lattice thermal conductivity in polycrystalline SnSe. Large static lattice strain created by lattice dislocations and stacking faults causes an effective shortening in phonon relaxation time, resulting in ultralow lattice thermal conductivity.

Improved Figure of Merit of CuSnSe via Band Structure Modification and Energy-Dependent Carrier Scattering.

As an ecofriendly thermoelectric material with intrinsic low thermal conductivity, ternary diamond-like CuSnSe (CSS) has attracted much attention. Nevertheless, its figure of merit, ZT, is limited by its small thermopower () and power factor (PF). Here, we show that an increase in thermopower by 63% and a carrier-mobility rise of 81% at 300 K can be simultaneously achieved through 5% substitution of Fe for Sn due to both enhancement of electronic density of states and degeneracy of multiple valence band maxima, which lead to high PF = 10.

Thermoelectric performance of nanostructured In/Pb codoped SnTe with band convergence and resonant level prepared via a green and facile hydrothermal method.

SnTe is considered as a promising alternative to the conventional high-performance thermoelectric material PbTe, which inspired the thermoelectric community for a while. Here, we design a green, facile and low-energy-intensity hydrothermal route without involving any toxic or unstable chemicals to fabricate SnTe-based thermoelectric materials. Ultralow lattice thermal conductivity and enhanced thermoelectric performance are achieved via the combination of band engineering and nanostructuring.