Hidden structures: a driving factor to achieve low thermal conductivity and high thermoelectric performance.

The long-range periodic atomic arrangement or the lack thereof in solids typically dictates the magnitude and temperature dependence of their lattice thermal conductivity (). Compared to crystalline materials, glasses exhibit a much-suppressed across all temperatures as the phonon mean free path reaches parity with the interatomic distances therein. While the occurrence of such glass-like thermal transport in crystalline solids captivates the scientific community with its fundamental inquiry, it also holds the potential for profoundly impacting the field of thermoelectric energy conversion.

Room-Temperature Synthesis and Low Thermal Conductivity in Nanocrystalline AgCuS.

Noble-metal-based chalcogenide materials recently gained massive attention in the field of thermoelectrics. In most cases, materials are synthesized using (i) high-temperature solid-state reactions or (ii) soft chemical methods where temperature requirements are lower than those of solid-state reactions (generally below 400 °C). Herein, we present a simple, surfactant-free, room-temperature, and energy-efficient synthesis of AgCuS nanocrystals.

Chemically Transformed Ag Te Nanowires on Polyvinylidene Fluoride Membrane For Flexible Thermoelectric Applications.

Flexible thermoelectric devices of nanomaterials have shown a great potential for applications in wearable to remotely located electronics with desired shapes and geometries. Continuous powering up the low power flexible electronics is a major challenge. We are reporting a flexible thermoelectric module prepared from silver telluride (Ag Te) nanowires (NWs), which are chemically transformed from uniquely synthesized and scalable tellurium (Te) NWs.

Strained Lamellar Structures Leading to Improved Thermoelectric Performance in MgSbBi.

MgSbBi solid-solutions represent an important class of thermoelectric (TE) materials due to their high efficiency and variable operating temperature range. Of particular significance for midtemperature applications is the MgSbBi composition whose superior thermoelectric (TE) performance is attributed to the complex conduction band edge in conjunction with alloy dominated phonon scattering. In this work, we show that microstructure also plays a significant role in lowering the lattice thermal conductivity which in turn affects the overall TE performance (change in peak zT values between 1.

Chemical Bonding Tuned Lattice Anharmonicity Leads to a High Thermoelectric Performance in Cubic AgSnSbTe.

Comprehension of chemical bonding and its intertwined relation with charge carriers and heat propagation through a crystal lattice is imperative to design compounds for thermoelectric energy conversion. Here, we report the synthesis of large single crystal of new p-type cubic AgSnSbTe which shows an innately ultra-low lattice thermal conductivity (κ ) of 0.47-0.

Insights into Low Thermal Conductivity in Inorganic Materials for Thermoelectrics.

Efficient manipulation of thermal conductivity and fundamental understanding of the microscopic mechanisms of phonon scattering in crystalline solids are crucial to achieve high thermoelectric performance. Thermoelectric energy conversion directly and reversibly converts between heat and electricity and is a promising renewable technology to generate electricity by recovering waste heat and improve solid-state refrigeration. However, a unique challenge in thermal transport needs to be addressed to achieve high thermoelectric performance: the requirement of crystalline materials with ultralow lattice thermal conductivity (κ).

Enhanced Band Convergence and Ultra-Low Thermal Conductivity Lead to High Thermoelectric Performance in SnTe.

SnTe, a structural analogue of champion thermoelectric (TE) material PbTe, has recently attracted wide attention for TE energy conversion. Herein, we demonstrate a co-doping strategy to improve the TE performance of SnTe via simultaneous modulation of electronic structure and phonon transport. The electrical transport is optimized by 3 mol % Ag doping in self-compensated SnTe (i.

Intrinsically ultralow thermal conductive inorganic solids for high thermoelectric performance.

Thermoelectric materials which can convert heat energy to electricity rely on crystalline inorganic solid state compounds exhibiting low phonon transport (i.e. low thermal conductivity) without much inhibiting the electrical transport.

Metavalent Bonding in GeSe Leads to High Thermoelectric Performance.

Orthorhombic GeSe is a promising thermoelectric material. However, large band gap and strong covalent bonding result in a low thermoelectric figure of merit, zT≈0.2.

Ferroelectric Instability Induced Ultralow Thermal Conductivity and High Thermoelectric Performance in Rhombohedral -Type GeSe Crystal.

The orthorhombic phase of GeSe, a structural analogue of layered SnSe (space group: ), has recently attracted attention after a theoretical prediction of high thermoelectric figure of merit, zT > 2. The experimental realization of such high performance in orthorhombic GeSe, however, is still elusive (zT ≈ 0.2).

Highly Converged Valence Bands and Ultralow Lattice Thermal Conductivity for High-Performance SnTe Thermoelectrics.

A two-step optimization strategy is used to improve the thermoelectric performance of SnTe via modulating the electronic structure and phonon transport. The electrical transport of self-compensated SnTe (that is, Sn Te) was first optimized by Ag doping, which resulted in an optimized carrier concentration. Subsequently, Mn doping in Sn Ag Te resulted in highly converged valence bands, which improved the Seebeck coefficient.