High Lattice Thermal Conductivity Research Articles

Achieving high carrier mobility and low lattice thermal conductivity in GeTe-based alloys by cationic/anionic co-doping

Achieving high carrier mobility and low lattice thermal conductivity in GeTe-based alloys by cationic/anionic co-doping

High‐Performance CaMg2Bi2‐Based Thermoelectric Materials Driven by Lattice Softening and Orbital Alignment via Cadmium Doping

AbstractZintl compounds such as n‐type Mg3(Sb,Bi)2 show promising thermoelectric applications benefiting from their high valley degeneracy and low lattice thermal conductivity. However, the heavier p‐type AMg2X2 (A = Ca, and Yb; X = Bi and Sb) Zintl counterparts even exhibit a higher κlat due to strong chemical bonding. Reducing κlat of AMg2X2 is an important route for improving thermoelectric performance. Herein, it is found that Cd doping at the Mg site in CaMg2Bi2 can weaken intralayer covalent bonds and soften acoustic phonons, as well as fill the optical phonon gap. These effects result in large atomic displacement, low phonon group velocity, and strong lattice vibration anharmonicity. Doping 10% Cd leads to a reduction of 56% in the κlat of CaMg2Bi2. Moreover, Cd doping promotes orbital alignment and thus increases the density‐of‐states effective mass and Seebeck coefficient. Eventually, in conjunction with carrier concentration optimization by Na doping and band structure engineering by Ba doping, a high ZT of ≈1.3 at 873 K in (Ca0.85Ba0.15)0.995Na0.005Mg1.85Cd0.15Bi2 sample is realized. This work highlights the significant role of manipulating chemical bonding in suppressing phonon propagation of semiconductors.

Simultaneous manipulation of electrical and thermal properties to improve the thermoelectric performance of CuInTe2

The unique transport properties make CuInTe2 emerge as a promising thermoelectric material. However, the intrinsically low carrier concentration and high lattice thermal conductivity of CuInTe2 limit its thermoelectric performance. In this work, firstly, we investigate the influence of excess Te on the electrical and thermal transport properties of CuInTe2. The results suggest that excess Te can act as both electron acceptors and phonon scattering centers, which simultaneously optimizes the carrier concentration and impedes the propagation of high-frequency phonons. Furthermore, the substitutional Ag/Cu defects integrated with excess Te lead to a further reduction in lattice thermal conductivity. DFT calculations indicate that the substitution of Ag for Cu can reduce phonon group velocity and intensify the acoustic phonon scattering, which agrees well with our experimental data. Finally, a high zT value of 1.03 is obtained @840 K for sample Cu0.8Ag0.2InTe2.2. This study demonstrates a facile but effective approach to boost the thermoelectric performance of chalcopyrite compounds.

Strong electron-phonon coupling and high lattice thermal conductivity in half-Heusler thermoelectric materials.

Traditional half-Heusler thermoelectric materials, identified as 18-electron compounds, are characterized by the high power factor and the high lattice thermal conductivity. Interestingly, the emerging 19-electron half-Heusler compounds were also found to be promising thermoelectric materials, but with a 5-10 times lower lattice thermal conductivity. Since the two kinds of compounds have similar chemical and physical structures, such as TiCoSb and VCoSb, the large difference in lattice thermal conductivity is a puzzling question. Here, we present a theoretical study to clarify the lattice thermal transport in half-Heusler thermoelectric materials. Based on electronic band structure analysis, we show that the two transition-metal elements in half-Heusler compounds form the strong and direct d-d interaction that is responsible for the high lattice thermal conductivity of 18-electron compounds. In 19-electron half-Heusler compounds, however, the extra valence electron enters the d-d antibonding states, which significantly weakens the atomic bond strength, leading to a large decrease in the cohesive energy. The resulting softened acoustic phonons enhance the phonon-phonon scattering, and thus reduce the lattice thermal conductivity significantly. By constructing an artificial 18-e compound V0.5Sc0.5CoSb, it is proved that the one less electron relative to VCoSb increases the lattice thermal conductivity significantly.

Preparation of High-Performance Mn-Doped SnTe Materials at High Pressure and High Temperature.

SnTe is an environmentally friendly medium-temperature thermoelectric material, but its inherent low power factor (PF) and high lattice thermal conductivity severely limit its application. In this study, based on the fact that Mn doping can induce band convergence, the high-pressure and high-temperature (HPHT) synthesis method was used to optimize the sample preparation and shorten the synthesis cycle to 30 min. The results show that the Sn0.93Mn0.10Te sample achieves the maximum PF value of 34.00 μW cm-1 K-2 at 775 K and PFave value of 21.36 μW cm-1 K-2 between 300-875 K. Microstructure analysis shows that the high-pressure synthesis method introduces abundant grain boundaries, various grain sizes, multiple defects, and pore structures into the sample. These microscopic crystal structures can effectively scatter phonons and lower the lattice thermal conductivity. The modification of these micromorphologies results in the Sn0.92Mn0.11Te sample attaining a minimum lattice thermal conductivity of 0.45 W m-1 K-1 at 625 K. The thermoelectric figure of merit (zT) of sample Sn0.92Mn0.11Te reaches a maximum value of 1.1 at 775 K, and the zTave reaches 0.63 in the range of 300-875 K. This study indicates that the synergistic effect of Mn element doping and microstructure modification can effectively optimize the thermoelectric transport performance of SnTe materials.

A comprehensive investigation on the physical properties of SiC polymorphs for high-temperature applications: A DFT study based on GGA and hybrid HSE06 exchange correlation functionals

This investigation reports the structural, electronic, bonding, elastic, mechanical, thermodynamic, thermal and optical characteristics of SiC polymorphs by DFT based GGA and hybrid HSE06 ab-initio computational methodology. SiC exhibits a multitude of structural orientations, with cubic (3C SiC) and hexagonal (4H SiC and 6H SiC) being the most prevalent. In my research, I aim to gain a comprehensive understanding of these SiC polymorphs and their potential suitability for high-temperature applications, especially as a cladding material for accident-tolerant fuel (ATF) in new-generation nuclear power plants (NPPs). The structural stability is ensured by geometry optimization and the relaxed parameters are agreed well with the previously reported findings. All the studied SiC polytypes reveal the semiconducting electronic property. By utilizing the hybrid HSE06 functional, the obtained electronic band gap meets the experimental results more closely than that obtained by the GGA approximation. The mechanical stability of all studied SiC polymorphs is evident from their elastic and mechanical properties, showcasing a brittle nature. The analysis of bond populations reveals the coexistence of both ionic and covalent bonds within the SiC structure. The thermoelectric and thermal characteristics of mechanically stable SiC polymorphs revealing that, all the compounds possess high lattice thermal conductivity and high melting point. Among these, 3C SiC stands out with the highest thermal conductivity of 172 Wm-1K−1 at 300 K and a melting temperature of 2840 K. The relatively low dielectric constant, high absorption coefficient and broad reflectivity spectra with > 90 % reflection in the UV region suggest that, SiC polymorphs can also be the potential candidates for optoelectronic devices. All the extreme physical stabilities make SiC polymorphs suitable for practical applications in high temperature environments.

Nanostructured Cu12+xSb4S13 tetrahedrites prepared by solvothermal synthesis in 1-(2-aminoethyl)piperazine for efficient thermal energy harvesting

Intrinsically low lattice thermal conductivity and the earth-abundant nature of elements make tetrahedrites very promising sulfur-based materials for thermoelectric applications. Although the thermoelectric performance of lightweight sulfides is usually restricted due to high lattice thermal conductivity, nanoengineering may effectively enhance the energy conversion performance of tetrahedrites by disturbing phonon transport. In this work, we modified our unique solvothermal synthesis method with 1-(2-aminoethyl)piperazine as a solvent and pure elements as reagents to obtain both copper-rich and copper-poor tetrahedrites with nanometric grain sizes ranging from 40 to 300 nm. The powders obtained were densified by the PECS method at T = 573 K and p = 40 MPa. The structural and thermal properties of the fabricated materials were systematically investigated as a function of temperature to revisit the phase evolution of the Cu-Sb-S system in the vicinity of the tetrahedrite compounds. The Seebeck coefficient of the investigated materials changes from 150 µVK−1 up to 400 µVK−1 at 300 K due to the effective tuning of the carrier concentration. In turn, the nanocrystalline nature of the prepared tetrahedrites, which influences the strong phonon scattering at grain boundaries, results in an ultralow lattice thermal conductivity of around 0.25 Wm−1K−1 at 300 K. As a result of the tuned electronic transport and ultralow lattice thermal conductivity, the highest ZT parameter of 0.9 at 596 K was achieved for the nominal composition Cu13Sb4S13. This is one of the best values reported to date for low-cost and environmentally friendly tetrahedrites at this temperature. The resultant nanomaterials can be used as components in novel inorganic and organic-inorganic composites for direct conversion of heat to electricity.

Thermoelectric properties of Co doped TiNiCo<sub><i>x</i></sub>Sn alloys fabricated by melt spinning

Although TiNiSn-based half-Heusler thermoelectric materials obtain high power factors, their high lattice thermal conductivity greatly hinders the improvement of thermoelectric properties. In this work, TiNiCo<sub><i>x</i></sub>Sn (<i>x</i> = 0–0.05) samples are prepared by melt spinning combined with spark plasma sintering method, and their phase, microstructure and thermoelectric properties are studied. The XRD results show that the main phase of all samples is TiNiSn phase, and no any other impurity phases are found, indicating that the high purity single phase can be prepared by rapid quenching process combined with SPS process. In the solidification process, the large cooling rate (10<sup>5</sup>–10<sup>6</sup> K/s) is conducive to obtaining the uniform nanocrystalline structure. The grains are closely packed, with grain sizes in a range of 200–600 nm. The grain sizes decrease to 50–400 nm for the Co-doping samples, which indicates that Co doping can reduce the grain size. For the <i>x</i> = 0 sample, the thermal conductivity of the rapid quenching sample is significantly lower than that of bulk sample, with an average decrease of about 17.8%. Compared with the TiNiSn matrix, the Co-doping sample has the thermal conductivity that decreases significantly, and the maximum decrease can reach about 38.9%. The minimum value of lattice thermal conductivity of TiNiCo<sub><i>x</i></sub>Sn samples is 3.19 W/(m·K). Therefore, Co doping can significantly reduce the <i>κ</i><sub>l</sub> values of TiNiCo<sub><i>x</i></sub>Sn (<i>x</i> = 0.01–0.05) samples. With the increase of Co doping amount <i>x</i>, n/p transition is observed in the TiNiCo<sub><i>x</i></sub>Sn samples, resulting in gradually reducing the conductivity and the power factor, and finally deteriorating the electrical transport performance, of which, the TiNiSn sample obtains the highest power factor of 29.56 W/(m·K<sup>2</sup>) at 700 K. The <i>ZT</i> value decreases with the Co doping amount <i>x</i> increasing, and the maximum <i>ZT</i> value of TiNiSn sample at 900 K is 0.48. This work shows that the thermal conductivity of TiNiSn can be effectively reduced by using the melt spinning process and magnetic Co doping.

Novel room-temperature full-Heusler thermoelectric material Li2TlSb.

High lattice thermal conductivity stemming from the intrinsically ordered crystal and strong interatomic bonds tends to be seen as the bottleneck for achieving excellent thermoelectric properties in full-Heusler (FH) semiconductors. In this work, we propose a novel Li-based FH compound Li2TlSb by substituting one Li atom with a Tl atom in Li3Sb. Then we systematically investigated its transport and thermoelectric properties based on self-consistent phonon (SCP) theory, electron-phonon scattering, and the Boltzmann transport equation. The theoretical calculation confirms that it exhibits outstanding mechanical properties and extreme environment adaptability. Surprisingly, the combination of an unexpectedly high spatial degeneracy and light electron dispersion at valence bands results in a high power factor in p-type systems. Additionally, the rattling behavior governed by the Tl atom and resonant bonding is responsible for ultra-low lattice thermal conductivity with 0.79 W m-1 K-1 at room temperature. Finally, a maximum p-type ZT value of 1.77 at 300 K has been achieved, which surpasses those of most of the traditional thermoelectric (TE) materials. Our results demonstrate that Li2TlSb serves as a potential candidate for room-temperature thermoelectric materials and simultaneously provides new insights for rationally designing novel FH materials in the future.

A Machine Learning Study on High Thermal Conductivity Assisted to Discover Chalcogenides with Balanced Infrared Nonlinear Optical Performance.

Exploration of novel nonlinear optical (NLO) chalcogenides with high laser-induced damage thresholds (LIDT) is critical for mid-infrared (mid-IR) solid-state laser applications. High lattice thermal conductivity (κL ) is crucial to increasing LIDT yet often neglected in the search for NLO crystals due to lack of accurate κL data. A machine learning (ML) approach to predict κL for over 6000 chalcogenides is hereby proposed. Combining ML-generated κL data and first-principles calculation, a high-throughput screening route is initiated, and ten new potential mid-IR NLO chalcogenides with optimal bandgap, NLO coefficients, and thermal conductivity are discovered, in which Li2 SiS3 and AlZnGaS4 are highlighted. Big-data analysis on structural chemistry proves that the chalcogenides having dense and simple lattice structures with low anisotropy, light atoms, and strong covalent bonds are likely to possess higher κL . The four-coordinated motifs in which central cations show the bond valence sum of +2 to +3 and are from IIIA, IVA, VA, and IIB groups, such as those in diamond-like defect-chalcopyrite chalcogenides, are preferred to fulfill the desired structural chemistry conditions for balanced NLO and thermal properties. This work provides not only an efficient strategy but also interpretable research directions in the search for NLO crystals with high thermal conductivity.

Enhancing Thermoelectric Performance in P-Type Sb2Te3-Based Compounds Through Nb─Ag Co-Doping with Donor-Like Effect.

P-type Sb2Te3 has been recognized as a potential thermoelectric material for applications in low-medium temperature ranges. However, its inherent high carrier concentration and lattice thermal conductivity led to a relatively low ZT value, particularly around room temperature. This study addresses these limitations by leveraging high-energy ball milling and rapid hot-pressing techniques to substantially enhance the Seebeck coefficient and power factor of Sb2Te3, yielding a remarkable ZT value of 0.55 at 323K due to the donor-like effect. Furthermore, the incorporation of Nb─Ag co-doping increases hole concentration, effectively suppressing intrinsic excitations ≈548K while maintaining the favorable power factor. Simultaneously, the lattice thermal conductivity can be significantly reduced upon doping. As a result, the ZT values of Sb2Te3-based materials attain an impressive range of 0.5-0.6 at 323K, representing an almost 100% improvement compared to previous research endeavors. Finally, the ZT value of Sb1.97Nb0.03Ag0.005Te3 escalates to 0.92 at 548K with a record average ZT value (ZTavg) of 0.75 within the temperature range of 323-573K. These achievements hold promising implications for advancing the viability of V-VI commercialized materials for low-medium temperature application.

Phase-dependent microstructure modification leads to high thermoelectric performance in n-type layered SnSe2

Microstructure control is crucial for thermoelectrics since it is intimately related to the scattering mechanism of both electrons and phonons. Herein, we propose a new strategy to modify microstructure by phase regulation that simultaneously induces high carrier mobility and low lattice thermal conductivity. As demonstrated in layered SnSe2, the addition of Cu can induce a phase transition from space group P3¯m1 to P63mc. Due to the enlarged formation energy of stacking faults in the later phase, the stacking fault density is greatly reduced after heat treatment that leads to an increased grain size. Accordingly, the carrier mobility of SnSe1.97Br0.03–3 % Cu sample is enhanced by 100 % at room temperature. Furthermore, the reduction of stacking fault density is accompanied by the formation of pores in the matrix, which results in low lattice thermal conductivity. As a result, a record peak zT of 1.13 for SnSe2-based materials is achieved at 773 K, and the attained ZTave of 0.62 is a record-high value among n-type polycrystalline layered materials working in intermediate-to-high temperature region. This work provides a feasible strategy to decouple the electron and phonon transport in layered thermoelectric compounds by phase-dependent microstructure modification.

Grain boundary engineering in metavalent SnTe: A simplified approach

The metavalently bonded SnTe has gathered enormous attention recently as an environmentally friendly alternative to PbTe. While some of the issues with SnTe, including its small bandgap and large valence band offset, have largely been resolved, its relatively high lattice thermal conductivity (κl) has remained a matter of concern. Here, we show that the temperature-induced vacancy migration in SnTe results in the growth of SnTe nanoparticles in the intergrain region. The enhanced grain boundary scattering due to this led to a highly reduced κl and increased carrier mobility, enhancing the zT of our SnTe by almost 70% over the zT of various SnTe ingot samples from this and several previous studies. The validity of this approach was further confirmed for a 3% Ag-doped SnTe sample, a composition well-investigated in the past. The simplicity and effectiveness of our approach enhance the prospect of SnTe for practical applications.

Enhanced thermoelectric figure-of-merit in ‘defective’ half-Heusler Nb0.8CoSb

The half Heusler alloys are potential mid-to-high temperature range thermoelectrics due to their high power factor, solid structural stability and high mechanical strength. However, the high lattice thermal conductivity inherent to these materials reduces the zT, rendering them less useful for practical applications. The ‘defective’ half-Heuslers provide an attractive alternative to mitigate these issues. In these materials, the intrinsic lattice defects present in the form of vacancies lower the lattice thermal conductivity substantially. Here, we study the effect of excess Nb and Sn doping in the defective half Heuslers Nb0.8+δCoSb1−xSnx. We show that Sn doping allows for: (i) optimizing the carrier concentration with a much finer control than if only δ is increased, and (ii) incorporation of a higher concentration of Nb in the structure. A combination of optimized carrier concentration and synergistic changes in the band structure, including the appearance of a new flat band near 50 meV above the Fermi energy due to excess Nb, suppresses the bipolarity and enhances the thermopower further at high temperatures as the average band effective mass of the carriers increases. We, therefore, obtain a high zT exceeding 1 at 1100 K for Nb0.85CoSb0.95Sn0.05. This value is ≈ 15% higher than the highest zT previously reported.

Enhancing Thermoelectric Performance of CuInTe2 via Trace Ag Doping at Indium Sites.

Thermoelectric technology can be utilized to directly convert waste heat into electricity, aiming at energy harvesting in an environmentally friendly manner. As a promising p-type thermoelectric material, CuInTe2 possesses a high inherent lattice thermal conductivity, which limits the practical implementation in the field of thermoelectricity. Herein, through the combination of vacuum melting and annealing along with hot-pressure sintering techniques, we demonstrated that CuIn0.95Ag0.05Te2 thermoelectric materials with trace Ag doping can exhibit a notably high Seebeck coefficient of 614 μV/K, arising from the high density-of-states effective mass and reduced carrier concentration. Owing to the diminished lattice thermal conductivity derived from Umklapp scattering induced by point defects and dislocation, stemming from the trace Ag doping at In sites rather than Cu sites, CuIn0.95Ag0.05Te2 exhibited a maximum figure of merit (ZT) of 1.38 at 823 K, an 18% enhancement over pristine CuInTe2, leading to a maximum average ZT of 0.67 across temperatures ranging from 303 to 823 K. In essence, our work underscores the efficacy of doping engineering and point defects in tailoring the thermoelectric performance of CuInTe2-based materials. This study not only contributes to advancing the fundamental understanding of thermoelectric enhancement but also lays out a practical pathway toward the realization of high-performance CuInTe2-based thermoelectric materials.

Enhanced figure of merit for famatinite Cu3SbSe4via band structure tuning and hierarchical architecture

The p-type Te-free Cu3SbSe4 with famatinite structure is a potential candidate for thermoelectric materials due to the low cost and eco-friendly constituent elements. However, its strong bipolar effect and high lattice thermal conductivity (κlat) are the main challenges for its performance enhancement. Herein, we report a new strategy to enhance its figure of merit zT ∼0.86 at 673 K for Cu3Sb0.95Fe0.05Se2.8S1.2via band structure tuning and hierarchical architecture. Firstly, S substituted Se atoms in lattice can widen the band gap to alleviate the bipolar effect. Secondly, Fe doping in Sb site significantly increases the density of states, thus increasing the carrier effective mass, and obtaining a remarkably high Seebeck coefficient of ∼560 μV/K at 300 K. Moreover, the induced hierarchical architecture defects resulting in a minimum κlat of ∼0.48 W·m−1·K−1 at 673 K. Consequently, the improved Seebeck coefficient combined with low thermal conductivity leads to an enhanced zT.

Oxide semiconductors for thermoelectric: The challenges and future

AbstractThe oxide thermoelectric (TE) ceramics have continued to attract the focus due to their high stability and low cost. However, their TE performance falls obviously backward with the typical TE compounds such as PbTe. Here, we revealed the reason for the difficulty of optimized performance is the large electronegativity difference between the metal and O ions in oxide, which results in strong electron localization and bond energy. The former leads to unfavorable electrical properties and the latter results in a high lattice thermal conductivity. Focusing on these issues, we briefly reviewed the strategies for electrical optimization including carrier concentration optimization, band gap tuning, and the density of state resonance, as well as the lattice thermal suppression strategies involving weakened bond, high entropy, grain size engineering, hierarchical architecture, textured polycrystal, and composite strategies for oxide TE ceramics. Finally, we proposed several possible perspectives for n‐type oxide TE ceramics, strategies for bond anisotropy, and predicted new TE oxides for further breakthroughs in oxide TE properties.

Optimizing CuFeS2 Chalcopyrite Thin Film Synthesis: A Comprehensive Three-Step Approach Using Ball-Milling, Thermal Evaporation, and Sulfurization Applied for Thermoelectric Generation

CuFeS2 (CFS) stands out as a promising narrow band-gap semiconductor for thermoelectric (TE) applications. However, its high lattice thermal conductivity is one of the factors hampering its potential for TE generation. A common strategy for tackling this problem is to produce this material in thin film form. Thus, this study aims to practically understand and optimize the synthesis of CFS 2D materials using a simple three-step approach of ball-milling, thermal evaporation, and sulfurization of the CuFe metallic precursors. The tools for thin film characterization employ X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDXS), and Hall-effect measurements. DFT phase diagrams are also used to understand the energy of formation of the secondary phases present in the film. Here, we highlight that the ball-milling mechanisms, allied with high vacuum and high energy density during evaporation, are essential for the interdiffusion of Cu and Fe during the evaporation process. The film presented a flower-like morphology and p-type semiconducting behavior. A proof-of-concept Thermoelectric Generator (TEG) was designed in an in-plane geometry, showing a power output per unit active area of 114 nW cm−2 (ΔT = 180 °C), comparable to other Cu-based materials, thus demonstrating the feasibility of this method of synthesis for TE applications.

Realizing high thermoelectric performance in p-type CaZn2Sb2-alloyed Mg3Sb2-based materials via band and point defect engineering

Layered Zintl-phase compound Mg3Sb2, possessing the advantages of high abundance, environmental friendliness, and low lattice thermal conductivity, are emerging materials for thermoelectric applications. However, p-type Mg3Sb2-based materials perform unfavorably than their n-type counterparts in terms of thermoelectric performance, which is mainly ascribed to undesirable valence band structure. Herein, we implement the strategy of alloying CaZn2Sb2 to achieve simultaneously improved electrical and thermal performance in p-type Mg3Sb2: (i) alloying CaZn2Sb2 not only optimizes the Seebeck coefficient, but also leads to improved carrier mobility; (ii) the mass and strain field fluctuations caused by alloying CaZn2Sb2 enhance phonon scattering, which significantly reduces the lattice thermal conductivity of the samples. By doping Ag in (Mg3.2Sb2)0.7(CaZn2Sb2)0.3 to realize higher electrical conductivity, the Mg2.22Ag0.02Ca0.3Zn0.6Sb2 sample reaches an excellent peak zT value of 0.90 at 823 K, which compares favorably to those of reported p-type Mg3Sb2-based materials. This study develops an effective pathway to advance thermoelectric performance of p-type Mg3Sb2-based materials.

XMoSiN2 (X = S, Se, Te): A novel 2D Janus semiconductor with ultra-high carrier mobility and excellent thermoelectric performance

Two-dimensional (2D) semiconductor is a potential candidate for thermoelectric materials due to its high Seebeck coefficient. However, its high lattice thermal conductivity limits its applications in the field of thermoelectric materials. Here, we constructed an unsymmetrical 2D Janus semiconductor XMoSiN2(X = S, Se, Te) based on to significantly reduce the lattice thermal conductivity to only one-sixth that of at 300 K. We found that XMoSiN2 had an ultra-high carrier mobility up to 4640 cm2V−1s−1 leading to a metal-like electrical conductivity. Meanwhile, XMoSiN2 reserved the high Seebeck coefficient of . The lower lattice thermal conductivity and metal-like electrical conductivity resulted in excellent thermoelectric performance. possessed a record-high ZT value of 3.57 at 900 K. We believed that other materials with a similar structure to XMoSiN2 can also be potential candidates for high-performance thermoelectric materials. Our work provides valuable insights into designing novel high-performance thermoelectric materials.