Chemical Pressure-Driven Band Convergence and Discordant Atoms Intensify Phonon Scattering Leading to High Thermoelectric Performance in SnTe.

SnTe is an intriguing alternative to PbTe for midtemperature thermoelectric applications. Despite steady progress, its performance is lagging, in part because of the large energy difference(Δ) between the light (L-band) and heavy (Σ-band) valence bands and higher lattice thermal conductivity (κ). Previous studies have shown that applying pressure can enhance the Seebeck coefficient () and power factor () of SnTe.

High Thermoelectric Performance of n-type BiTeSe-Based Composites Incorporated with Both Inorganic and Organic Nanoinclusions.

N-type BiTeSe (BTS) alloy has relatively low thermoelectric performance as compared to its p-type counterpart, which restricts its widespread applications. Herein, we designed and prepared a novel composite system, which consists of an n-type BTS matrix incorporated with both inorganic and organic nanoinclusions. The results indicate that the thermopower of the composite samples can be enhanced by more than 19% upon incorporating inorganic nanophase AgBiS (ABS) due to the energy-dependent carrier scattering, which ensures a high power factor.

Simultaneous Enhancement of the Power Factor and Phonon Blocking in Nb-Doped WSe.

Transition-metal dichalcogenide WSe is a potentially good thermoelectric (TE) material due to its high thermopower (). However, the low electrical conductivity (σ), power factor (PF), and relatively large lattice thermal conductivity (κ) of pristine WSe degenerate its TE performance. Here, we show that through proper substitution of Nb for W in WSe, its PF can be increased by ∼10 times, reaching 5.

Theoretical Study of Intrinsic and Extrinsic Point Defects and Their Effects on Thermoelectric Properties of CuSnSe.

Current understanding of the intrinsic point defects and potential extrinsic dopants in p-type CuSnSe is limited, which hinders further improvement of its thermoelectric performance. Here, we show that the dominant intrinsic defects in CuSnSe are Cu and V under different chemical conditions, respectively. The presence of V will damage the hole conduction network and reduce hole mobility.

Achieving higher thermoelectric performance of n-type PbTe by adjusting the band structure and enhanced phonon scattering.

Due to the very distinct electronic band structure and lower power factor, the exploration of n-type PbTe as thermoelectric materials has historically fallen behind that of p-type PbTe. In this work, n-type PbSbTe-based composites incorporated with CuSbS nanoparticles are synthesized and investigated. Sb doping is utilized to modify its carrier concentration in order to obtain n-type PbTe materials with a high power factor.

Boosting Thermoelectric Performance of CuSnSe Comprehensive Band Structure Regulation and Intensified Phonon Scattering by Multidimensional Defects.

As an eco-friendly thermoelectric material, CuSnSe has recently drawn much attention. However, its high electrical resistivity ρ and low thermopower prohibit its thermoelectric performance. Herein, we show that a widened band gap and the increased density of states are achieved S alloying, resulting in 1.

Improved Thermoelectric Performance of CuSbS through Gd-Substitution Induced Enhancement of Electronic Density of States and Phonon Scattering.

CuSbS has aroused great interest because of its earth-abundant constituents and intrinsic low thermal conductivity. However, the applications of CuSbS are hindered by its poor thermoelectric performance. Herein, it is shown that Gd substitution not only causes a significant increase in both electrical conductivity σ and thermopower but also leads to dramatic drop in lattice thermal conductivity .

Improving the thermoelectric performance of CuSnSe regulating micro- and electronic structures.

As a p-type thermoelectric material, Cu2SnSe3 (CSS) has recently drawn much attention, with its constituents being abundant and free of toxic elements. However, the low electrical conductivity σ and thermopower S of CSS prohibit its thermoelectric performance. Here, we show that through mechanical milling, a 14 times increase in σ, around a 2-fold rise in S and a 40% reduction in the lattice thermal conductivity κL (at 300 K) can be achieved, amazingly.

Achieving High Thermoelectric Performance in p-Type BST/PbSe Nanocomposites through the Scattering Engineering Strategy.

To achieve high thermoelectric conversion efficiency in BiSbTe (BST) alloy is vital for its applications in low-grade energy harvesting. Here, we show that 56% increase in the power factor (PF) (from 16 to 25 μW cm K) and 32% reduction of lattice thermal conductivity κ (from 0.56 to 0.

Ultralow Thermal Conductivity and High Thermoelectric Performance of N-type BiTeSe-Based Composites Incorporated with GaAs Nanoinclusions.

BiTeSe (BTS) is known to be the unique n-type commercial thermoelectric (TE) alloy used at room temperatures, but its figure of merit () is relatively low, and it is vital to improve its for its wide applications. Here, we show that incorporation of an appropriate amount of GaAs nanoparticles in BTS not only causes the large enhancement of Seebeck coefficients because of energy-dependent carrier scattering, but also gives rise to drastic reduction of lattice thermal conductivity κ. Specifically, ultralow κ ∼ 0.

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.