TE Performance Research Articles

Effects of Heavy Ion Irradiation on the Thermoelectric Properties of In2(Te1-xSex)3 Thin Films.

Ion irradiation is an exceptionally effective approach to induce controlled surface modification/defects in semiconducting thin films. In this investigation, ion-irradiated Se-Te-based compounds exhibit electrical transport properties that greatly favor the transformation of waste heat into electricity. Enhancements of both the Seebeck coefficient (S) and the power factor (PF) of In2(Te0.98Se0.02)3 films under 120 MeV Ni9+ ion irradiation were examined. The maximum S value of the pristine film was about ~221 µVK-1. A significantly higher S value of about ~427 µVK-1 was obtained following irradiation at 1 × 1013 ions/cm2. The observed S values suggest the n-type conductivity of these films, in agreement with Hall measurements. Additionally, Ni ion irradiation increased the PF from ~1.23 to 4.91 µW/K2m, demonstrating that the irradiated films outperformed the pristine samples. This enhancement in the TE performance of the In2(Te0.98Se0.02)3 system is elucidated by irradiation-induced effects that are revealed by structural and morphological studies.

A study of interfacial electrical contact resistances of thermoelectric generators for hypersonic vehicles by experimental measurements and two-scale numerical simulations

An enormous amount of aerodynamic heat is produced on the surface of hypersonic vehicles, and the thermoelectric generator (TEG) technique holds the potential to convert aerodynamic heat into electric energy. In a TEG, the micrometer-scale roughness on TE legs and electrodes surfaces leads to the constriction of interfacial electric current and brings about electrical contact resistance (ECR). The heat transfer and conversion processes of a TEG are greatly influenced by such type of ECR. In this work, a TEG includes two ceramic substrates and a middle TE layer is established, and the TE layer consists of insulation material, N- and P-type TE legs and electrodes to connect the TE legs. The ECR and its effects on the TEG performance are studied by two-scale numerical simulations and experimental measurements. First, the practical topography of rough surfaces for TE legs and electrodes is measured, and the micrometer-scale ECR prediction numerical models are established based on the reconstructed topography. An ECR measurement platform is developed and the platform consists of a pressure device, power supply and data acquisition system which are used to provide loading pressures, voltage, and acquisition of electric current and voltage signals, respectively. The ECRs under different temperatures, loading pressures and gap mediums are then predicted and the numerical models are validated by a series of measurements. Second, the TE conversion process of TEG is simulated by a millimeter-scale model including insulation materials, TE legs, electrodes, and equivalent interfacial layers of ECR. The influence of ECR on the TE performance of TEG for the hypersonic vehicle is thus clarified.

(Digital Presentation) Cathodic Exfoliation of Few-Layer Tellurium As Electrocatalyst Support for Hydrogen Evolution

Few-layer tellurium represents the two-dimensional (2D) form of tellurium crystal with the majority of the Te atoms exposed on its surface. Recent studies demonstrated that 2D Te has good environmental stability and high charge carrier mobility, making it suitable electrocatalyst support to host active sites and assist electron transfer between the electrode and the sites [1]. Yet, its mass production for electrocatalysis application remains challenging.In this study, we present a simple cathodic exfoliation method to exfoliate commercially available Te crystal directly into few-layer tellurium with exceptionally high yield [2] (see Figure 1A). Using alkaline aqueous electrolyte (1.0 M KOH), Te nanosheets with the thickness of 7~10 nm and lateral size of 1~4 µm were produced at an applied potential of −0.42 V (vs. RHE). Combining in situ Raman spectroscopy and ex situcharacterization results, we were able to reveal the exfoliation mechanism, where the in situ generated ditelluride (Te2 2−) anions on the nanosheets played the critical role of separating nanosheets from the bulk crystal (see Figure 1B).At the presence of transition metal ions in the electrolyte, such as Pt2+ and Ni2+, simultaneous surface doping of Te nanosheets was enabled by the interaction between Te2 2− anions and metal ions, producing Pt/Ni-doped Te with tunable doping level. Such doped nanosheets exhibited high stability and hydrogen evolution reaction (HER) activity. Particularly at high potential, Pt-doped Te nanosheets outperformed both polycrystalline Pt and commercial Pt/C catalysts (see Figure 1C). We suggested a collaborative hydrogen production mechanism via Volmer–Heyrovsky pathway to justify such unusual activity. In short, at HER conditions, the surface Te atoms of Pt-doped Te nanosheets are reduced to Te2 2− anions. Such species can help attract protons and assist their transfer to adjacent Pt atoms, where the protons are reduced to form hydrogen (see Figure 1D). Figure 1 (A) Experimental setup and photos of the electrochemical exfoliation of Te crystal; (B) Exfoliation mechanism; (C) HER performance and relative energy of Pt-doped Te with various doping levels; (D) Collaborative HER mechanism. Reference: Shi, Z.; Cao, R.; Khan, K.; Tareen, A. K.; Liu, X.; Liang, W.; Zhang, Y.; Ma, C.; Guo, Z.; Luo, X.; Zhang, H., Nano-Micro Lett. 2020, 12 (1), 99. Zheng, W.; Li, Y.; Liu, M.; Lee, L. Y. S., Small 2021, 17 (18), e2007768. Figure 1

Environmentally friendly ionic side chain organic small molecule/single-walled carbon nanotube composites have high TE performance

Environmentally friendly ionic side chain organic small molecule/single-walled carbon nanotube composites have high TE performance

Enhanced thermoelectric performance of n-type Bi2Te2.7Se0.3 via a simple liquid-assisted shear exfoliation

• By using a simple approach of liquid-assisted shear exfoliation (LASE) coupled with SPS, highly-oriented bulk ceramics of Bi 2 Te 2.7 Se 0.3 with effectively reduced grain size were obtained. • A peak ZT value of 0.83 at 448 K was obtained in-plane due to a synergy of enhanced power factor and suppressed lattice and bipolar thermal conductivities, which is 95% higher that of the pristine sample, demonstrating LASE as a useful assistant process for enhancing the performance of layered thermoelectric materials. A liquid-assisted shear exfoliation (LASE) as a new powder metallurgy method coupled with spark plasma sintering (SPS) was applied for n -type Bi 2 Te 2.7 Se 0.3 and the effects on microstructure and anisotropic transport properties were investigated. Results revealed an effective reduction of average grain size due to LASE and a high texturing in the bulks. Moreover, along the in-plane direction, electrical conductivity was increased noticeably due to an enhanced carrier concentration, leading to a significantly improved power factor of 25 μW cm –1 K –2 at 303 K. Meanwhile, the total thermal conductivity was reduced effectively owing to reduction both in lattice component due to enhanced phonon scattering with the grain size reduction, and in the bipolar component inhibited by the increased carrier concentration. Ultimately, a peak thermoelectric figure of merit (ZT) value of 0.83 was obtained at 448 K along the in-plane direction, increased by 95% compared with the pristine one. These results demonstrate the LASE process as a useful assistant method for enhancing the TE performance of layered materials.

Review on Wearable Thermoelectric Generators: From Devices to Applications

Wearable thermoelectric generators (WTEGs) can incessantly convert body heat into electricity to power electronics. However, the low efficiency of thermoelectric materials, tiny terminal temperature difference, rigidity, and neglecting optimization of lateral heat transfer preclude WTEGs from broad utilization. In this review, we aim to comprehensively summarize the state-of-the-art strategies for the realization of flexibility and high normalized power density in thermoelectric generators by establishing the links among materials, TE performance, and advanced design of WTEGs (structure, heatsinks, thermal regulation, thermal analysis, etc.) based on inorganic bulk TE materials. Each section starts with a concise summary of its fundamentals and carefully selected examples. In the end, we point out the controversies, challenges, and outlooks toward the future development of wearable thermoelectric devices and potential applications. Overall, this review will serve to help materials scientists, electronic engineers, particularly students and young researchers, in selecting suitable thermoelectric devices and potential applications.

Excellent thermoelectric properties and stability realized in copper sulfides based composites via complex nanostructuring

Nanostructuring is a conventional approach to decrease thermal conductivity, nevertheless, the effect of grain boundaries on scattering phonon is limited. Herein, a new approach of constructing complex nanostructures is proposed. The copper sulfides-based nanocomposites with high thermoelectric properties and phase stability were fabricated by combining with solid-state reaction and spark plasma sintering techniques. The main phase of Cu12Sb4S13 and Cu1.96S with complex nanostructures is obtained by introducing CoSb3 additive to Cu1.8S matrix. Hole concentration in p-type composites is tailored by regulating Cu vacancies concentration and Co3+ doping in Cu+ sites, resulting in the significantly enhanced Seebeck coefficient and carrier thermal conductivity reduction. Furthermore, an ultralow thermal conductivity of 0.47 W m−1 K−1 at 773 K is achieved due to the tuned carrier concentration and the enhanced phonons scattering by continuous nanopores, extra phase interfaces and nanoprecipitates. The record high ZT of 1.6 is achieved at 773 K in Cu-S based thermoelectric material system for the composite specimen, namely Cu1.8S-5 wt.% CoSb3. Our result provides a new strategy to construct complex nanostructures and realize spontaneous composition regulation in improving TE performance of copper sulfide-based materials.

Structural Modifications and Enhanced Thermoelectric Performance of CuI Nanoparticles Induced via Al‐Doping

AbstractThermoelectric (TE) materials are of great importance for harvesting thermal energy from waste or solar heat. One of the promising TE materials is copper iodide (CuI), which is nontoxic, earth‐abundant, and has a high Seebeck coefficient at room temperature (RT). The TE performance of CuI nanoparticles (NPs) is found to be further enhanced by appropriate Al‐doping through reducing the particle size and simultaneously enhancing the electrical conductivity by a factor of 10. Al‐doping manifests to enlarge the deviation from stoichiometric composition, namely δ in Cu1‐δI, and can further assist co‐doping of iodine to generate carrier holes. The thermal conductivity is also reduced by Al‐doping and overall, the figure of merit increases from 0.01 for the pure CuI nanocrystals to ≈0.12 at 300 K and ≈0.2 at 385 K, respectively, for the 0.23 mol% Al‐doped NPs. The power generation characteristics of a single leg TE module made up of the 0.23 mol% Al‐doped CuI measured under real‐time conditions firmly indicate its suitability as a TE generator operating near RT.

Decoupling of thermoelectric transport performance of Ag doped and Se alloyed tellurium induced by carrier mobility compensation

• Ag doping and Se alloying optimize the thermoelectric performance of Te. • Se alloying effectively reduces lattice thermal conductivity of Te by refining grain of Te and introducing high density-defects. • Ag doping regulates the micro morphology and increases the grain size of Te-Se solid solution. • Ag doping successfully compensates the lost carrier mobility due to Se alloying while retains the ability of Te-based matrix to scatter high-frequency (ω) and medium-frequency phonons. • Sb doping effectively optimizes the carrier concentration of Te. Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity ( κ L ) of tellurium by introducing multidimensional lattice defects. However, extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix. In this paper, we propose that the incorporation of Ag could successfully compensate the lost carrier mobility ( μ H ) due to Se alloying through the regulation of microstructure, resulting in the higher power factor (PF) than that of samples without Ag. After composition optimization, the κ L decreased from 1.29 W m −1 K −1 of Te 0.99 Sb 0.01 to 1.05 W m −1 K −1 of Te 0.94 Ag 0.02 Se 0.03 Sb 0.01 at 350 K, while the PF remained unchanged or even slightly increased. Benefit from the synergistic effect of carrier mobility compensation and phonon scattering, a maximum zT of 0.91 at 573 K and an average zT of 0.57 (between 298 and 573 K) are achieved in Te 0.94 Ag 0.02 Se 0.03 Sb 0.01 . This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.

Diagnostic Performance of 2D-Shear Wave Elastography versus TE in Patients with Compensated Liver Cirrhosis

Diagnostic Performance of 2D-Shear Wave Elastography versus TE in Patients with Compensated Liver Cirrhosis

A case of perfect convergence of light and heavy hole valence bands in SnTe: the role of Ge and Zn co-dopants

Remarkable engineering of the electronic structure of SnTe by co-doping Ge and Zn. The synergistic effect of the resonance level, increase in the band gap and perfect convergence of valence sub-bands with reduced thermal conductivity leads to enhanced TE performance.

High-performance thermoelectric properties of strained two-dimensional tellurium

Elemental two-dimensional (2D) materials in monolayer form are attractive due to their simplicity and indigenous properties. In the present study, we investigate the influence of biaxial strain on group VI elemental 2D material of tellurium, which has been discussed for its potential in various applications. Considering realistic estimates of strain that may be imposed to monolayer Te through van der Waals heterostructing with other known 2D materials, we demonstrate that the structural, electrical, and thermal transport properties can get strongly influenced by strain. Importantly, through strain engineering, the thermoelectric performance of elemental 2D Te in $p$-type doping can be made comparable to that of the known binary or ternary layered compound at room temperature, and can outperform the known binary or ternary layered compounds at high to moderate temperature. The $ZT$ of monolayer Te is found to reach a value of 6.07 at 800 K under tensile strain, being larger than 2 for temperature greater than 400 K. Our study provides a way to tune the thermoelectric properties of 2D Te for future applications.

Characterization of Structural Defects in (Cd,Zn)Te Crystals Grown by the Travelling Heater Method

Structural defects and compositional uniformity remain the major problems affecting the performance of (Cd, Zn)Te (CZT) based detector devices. Understanding the mechanism of growth and defect formation is therefore fundamental to improving the crystal quality. In this frame, space experiments for the growth of CZT by the Travelling Heater Method (THM) under microgravity are scheduled. A detailed ground-based program was performed to determine experimental parameters and three CZT crystals were grown by the THM. The structural defects, compositional homogeneity and resistivity of these ground-based crystals were investigated. A ZnTe content variation was observed at the growth interface and a high degree of stress associated with extensive dislocation networks was induced, which propagated into the grown crystal region according to the birefringence and X-ray White Beam Topography (XWBT) results. By adjusting the growth parameters, the ZnTe variations and the resulting stress were efficiently reduced. In addition, it was revealed that large inclusions and grain boundaries can generate a high degree of stress, leading to the formation of dislocation slip bands and subgrain boundaries. The dominant defects, including grain boundaries, dislocation networks and cracks in the interior of crystals, led to the resistivity variation in the crystals. The bulk resistivity of the as-grown crystals ranged from 109 Ωcm to 1010 Ωcm.

Whole Fabric-Assisted Thermoelectric Devices for Wearable Electronics.

Flexible thermoelectric generators (f‐TEGs) have demonstrated great potential in wearable self‐powered health monitoring devices. However, the existing wearable f‐TEGs are neither flexible enough to bend and stretch while maintaining the device's integrity with a good TE performance nor directly compatible with clothes materials. Here, ultraflexible fabric‐based thermoelectric generators (uf‐TEGs) are proposed with conductive cloth electrodes and elastic fabric substrate. The patterned elastic fabric substrate fits the rigid cuboids well, together with serpentine structured cloth electrodes, rendering uf‐TEG with excellent integrity and flexibility, thereby achieving a highly functional TE performance when strain reaches 30% or on arbitrarily shaped heat sources. The uf‐TEGs show a large peak power of 64.10 μW for a temperature difference of 33.24 K with a high voltage output of 111.49 mV, which is superior compared to previously reported fabric‐based TEG devices, and it is still functional after the water immersion test. Besides the energy harvesting function, with both the temperature sensing ability and the touch perception, this uf‐TEG is demonstrated as the electrical skin when mounted on a robot. Moreover, due to the wind‐sensitive performance and self‐power ability, the uf‐TEGs are assembled on cloth as wearable health and motion monitoring devices.

Enhancement of thermoelectric performance of argyrodite Ag8GeSe6 via isoelectronic substitution of Sn for Ge

Argyrodite compound Ag8GeSe6 (AGS) as one of the superionic conductors possesses unique crystal structures: the rigid anionic framework [GeSe4]4- and mobile cation (Ag). Hence its lattice thermal conductivity is rather low due to the action of the mobile cation (Ag). However, this compound has neither high carrier concentration (0.15 × 1016 cm−3 at 300 K and 0.61 × 1016 cm−3 at 370 K) nor high thermoelectric performance (the figure of the merit (ZT) of<0.4). So in this work, we enhance the carrier concentration by more than one order of magnitude at 373 K through the band structure engineering via the substitution of Sn for Ge. In the mean time, the lattice thermal conductivity (κL) reduces from 0.26 W/mK to 0.16 W/mK at 750 K. As a consequence, the ZT value of Ag8Ge0.9Sn0.1Se6 is boosted to ~ 1.05. This value is about 2.8 times that of the pristine AGS (0.38 at 750 K) and stands among the highest in this family so far. The above results confirm that the isoelectronic substitution of Sn for Ge in the anionic framework of AGS is an effective way to realize its high TE performance.

Thermoelectric Performance Enhancement of Film by Pulse Electric Field and Multi-Nanocomposite Strategy.

Thermoelectric (TE) film has wide potential application in low-grade waste heat recovery and TE generation due to its quick response and multifunctional integration. Multi-nanocomposite is a promising method to solve the difficulty of maintaining temperature difference and achieving a high figure of merit ZT. However, the depletion layer induced by the multi-nanocomposite typically degrades performance. This study presents a simple and convenient method to solve this problem by pulse electric field (PEF). Prototypical TE Bi2 Te3 is selected as the objective film. The strong current density effect of PEF removes the depletion layer among carbon nanotubes (CNT) and Bi2 Te3 grains. Thus, the CNT nanocomposite with PEF treatment breaks the trade-off between electrical conductivity and Seebeck coefficient, achieving a power factor of 4400 µW m-1 K-2 which stabilizes after annealing effect to 2920 µW m-1 K-2 , a record for Bi2 Te3 films. Simultaneously, the self-assembled porosity decreases thermal conductivity via phonon scattering while still maintaining a high electrical conductivity of 3130 S cm-1 . Thus, the porosity helps maintain the temperature difference and thereby enables a sharp increase in output power. These results indicate that the combination of PEF and multi-nanocomposite is a new method to enhance TE performance, which would have a potential application in the commercial field.

Solution-phase p-type doping of highly enriched semiconducting single-walled carbon nanotubes for thermoelectric thin films

Single-walled carbon nanotubes (SWCNTs) are attractive materials for next-generation energy-harvesting technologies, including thermoelectric generators, due to their tunable opto-electronic properties and high charge carrier mobilities. Controlling the Fermi level within these unique 1D nanomaterials is often afforded by charge transfer interactions between SWCNTs and electron or hole accepting species. Conventional methods to dope SWCNT networks typically involve the diffusion of molecular redox dopant species into solid-state thin films, but solution-phase doping could potentially provide routes and/or benefits for charge carrier transport, scalability, and stability. Here, we develop a methodology for solution-phase doping of polymer-wrapped, highly enriched semiconducting SWCNTs using a p-type charge transfer dopant, F4TCNQ. This allows doped SWCNT inks to be cast into thin films without the need for additional post-deposition doping treatments. We demonstrate that the introduction of the dopant at varying stages of the SWCNT dispersion process impacts the ultimate thermoelectric performance and observe that the dopant alters the polymer selectivity for semiconducting vs metallic SWCNTs. In contrast to dense semiconducting polymer films, where solution-phase doping typically leads to disrupted morphologies and poorer TE performance than solid-state doping, thin films of solution-doped s-SWCNTs perform similarly to their solid-state doped counterparts. Interestingly, our results also suggest that solution-phase F4TCNQ doping leads to fully ionized and dimerized F4TCNQ anions in solid-state films that are not observed in films doped with F4TCNQ after deposition. Our results provide a framework for the application of solution-phase doping to a broad array of high-performance SWCNT-based thermoelectric materials and devices that may require high-throughput deposition techniques.

Realizing high thermoelectric performance in n-type SnSe polycrystals via (Pb, Br) co-doping and multi-nanoprecipitates synergy

Both p- and n-type SnSe single crystals have been reported to possess high thermoelectric performances, thus highlighting the possibility for commercialization. Polycrystalline SnSe that has better mechanical properties however possesses inferior thermoelectric properties compared to single crystal SnSe. In this work, n-type polycrystalline SnSe0.95 + x wt% PbBr2 (x = 0, 0.5, 1, and 1.5) samples were synthesized by combining mechanical alloying and spark plasma sintering technology. The effects of PbBr2 doping on thermoelectric performance of SnSe were studied in detail. The results show that the carrier concentration was dramatically increased from 2.51 × 1017 cm−3 in pure SnSe0.95 to 1.79 × 1019 cm−3 in SnSe0.95 + 1.5 wt% PbBr2, further resulting in an enhanced electrical conductivity. Multi-nanoprecipitates are present in the samples, including SnO, SnPb and SnBrxOy, which possibly affect the Seebeck coefficient and the lattice thermal conductivity. A peak ZT value of 1.1 was obtained at 773 K for the SnSe0.95 + 1.0 wt% PbBr2 sample. This work highlights that PbBr2 is an effective dopant to improve the TE performance of n-type polycrystalline SnSe.

MAIZE /SORGHUM - BASED DRIED BREWERS' GRAINS IN BROILER FINISHER DIETS

A 4- - day feeding trial was conducted to dermine the optianal substitution level of maize/sorghum - hased dried brewers' grains (MSDBG) for maize in broiler finisher diets. Six experimental broiler finisher diets were formulated such that 25%, 50% and 75% of the maize in diet 1 (the control) were replaced with MSDBG in diets 2, 3, and 4, respectively while diets 5 and 6 were like 3 and 4, respectievly but fortified with 4% palm oil,. Each diet was fed to a group of 48 broiler chicks for 40 days (week 4 to week 10 of age). There were no significant (P &gt; 0.05) differences among the groups in growth rate (43,95, 45,52, 45,11, 43,01, 45,80 and 43,92g/day, respectively). At replacement levels of 50% and 75% with or without palm oil, the birds consumed significantly (P &lt; 0.05) more feed than the group on the control diet (140.0, 151.4, 177.3, 174. 6, 174.2, 167.1 g/day, respectively). feed conversion ratio of the MSDRG groups was consequently sigificantly (P &lt; 0.05) inferior to the control. Addition of palm oil did not produce any notiocable effect on te performance of the birds. Feed cost for production of a kilogram of brioler was markedly reduced at the 75% replacement level.

Polycomponent doping improved thermoelectric performance of Cu&lt;sub&gt;3&lt;/sub&gt;SbSe&lt;sub&gt;4&lt;/sub&gt;-based solid solutions

&lt;sec&gt; Cu&lt;sub&gt;3&lt;/sub&gt;SbSe&lt;sub&gt;4&lt;/sub&gt;, one of the ternary p-type semiconductor materials with chalcopyrite structure, has aroused much interest in thermoelectrics due to its inherent large effective mass and narrow bandgap. Therefore, many researches have been done, which cover the single and/or multi-element doping to manipulate its band structure and introduce the point defects. Although great achievements have been made in recent years, the mechanism in Cu&lt;sub&gt;3&lt;/sub&gt;SbSe&lt;sub&gt;4&lt;/sub&gt; with respect to the phonon and electronic transport properties needs further investigating. &lt;/sec&gt;&lt;sec&gt; In this work, first, Sn and S are co-doped into Cu&lt;sub&gt;3&lt;/sub&gt;SbSe&lt;sub&gt;4&lt;/sub&gt; and then the resulting compound is alloyed with Ga&lt;sub&gt;2&lt;/sub&gt;Te&lt;sub&gt;3&lt;/sub&gt;, to improve its TE performance and understand the mechanism by calculating the band structure and crystal structure. The calculation of band structure reveals that an impurity band is created within the bandgap after co-doping Sn and S due to their contributions to the density of the states (DOS), which is directly responsible for the significant improvement in carrier concentration (&lt;i&gt;n&lt;/i&gt;&lt;sub&gt;H&lt;/sub&gt;) and electrical property. Therefore, the power factor (PF) is enhanced from 0.52 × 10&lt;sup&gt;–3&lt;/sup&gt; to 1.3 × 10&lt;sup&gt;–3&lt;/sup&gt; W·m&lt;sup&gt;–1&lt;/sup&gt;·K&lt;sup&gt;–2&lt;/sup&gt;. &lt;/sec&gt;&lt;sec&gt; Although the effect associated with the Ga (Te) residing at Sb (Se) sites on the band structure is limited due to the fact that both the single Ga- and single Te-doped band structure remain almost unchanged, the structural parameters (bond lengths and angles) of the polyhedrons [SeCu&lt;sub&gt;3&lt;/sub&gt;Sb] and [SbSe&lt;sub&gt;4&lt;/sub&gt;] before and after Te and Ga residing at Se and Sb sites respectively change remarkably. This yields the significant distortion of local lattice structure on an atomic scale. Therefore, the phonon scattering is enhanced and the lattice thermal conductivity (&lt;i&gt;κ&lt;/i&gt;&lt;sub&gt;L&lt;/sub&gt;) decreases from 1.23 to 0.81 W·K&lt;sup&gt;–1&lt;/sup&gt;·m&lt;sup&gt;–1&lt;/sup&gt; at 691 K. The reduction in &lt;i&gt;κ&lt;/i&gt;&lt;sub&gt;L&lt;/sub&gt; prevents the total thermal conductivity (&lt;i&gt;κ&lt;/i&gt;) from being enhanced rapidly. As a consequence, the highest ZT value of 0.64 is attained, which is much higher than that of the pristine Cu&lt;sub&gt;3&lt;/sub&gt;SbSe&lt;sub&gt;4&lt;/sub&gt; (ZT = 0.26). In addition, we not only present a synergistic strategy to separately optimize the phonon and electronic properties, but also fully elaborate its mechanism and better understand that this strategy is an effective way to improve the TE performance of the Cu&lt;sub&gt;3&lt;/sub&gt;SbSe&lt;sub&gt;4&lt;/sub&gt;-based solid solutions.&lt;/sec&gt;