Enhanced Thermoelectric Properties of Ti2CO2-Bismuthene-Ti2CO2: Optimized Power Factor and Reduced Thermal Conductivity.

In this study, bismuthene was intercalated between bilayer Ti2CTx to induce significant modifications in its electronic and phonon structures, thereby enhancing its thermoelectric properties. First-principles calculations reveal that the insertion of bismuthene transforms the Ti2CO2 system from a semiconductor into a metal and optimizes the thermoelectric properties of bilayer Ti2CO2 by enhancing its power factor and reducing its lattice thermal conductivity. Under the first-principles calculation parameters used in this study, the ZT of the Ti2CO2 system increased from 0.12 to 0.55. Conversely, for metallic bilayer MXenes, the introduction of bismuthene led to a substantial decrease in ZT (from 0.53 to 0.11 in the Ti2C system and from 0.07 to 0.05 in the Ti2CCl2 system). This study investigates the physical mechanisms underlying the enhancement of thermoelectric properties from both electronic and phononic perspectives and provides theoretical insights into the development and application of MXene-based thermoelectric materials.

In-Plane Overdamping and Out-Plane Localized Vibration Contribute to Ultralow Lattice Thermal Conductivity of Zintl Phase KCdSb.

Zintl phases typically exhibit low lattice thermal conductivity, which are extensively investigated as promising thermoelectric candidates. While the significance of Zintl anionic frameworks in electronic transport properties is widely recognized, their roles in thermal transport properties have often been overlooked. This study delves into KCdSb as a representative case, where the [CdSb4/4]- tetrahedrons not only impact charge transfer but also phonon transport. The phonon velocity and mean free path, are heavily influenced by the bonding distance and strength of the Zintl anions Cd and Sb, considering the three acoustic branches arising from their vibrations. Furthermore, the weakly bound Zintl cation K exhibits localized vibration behaviors, resulting in strong coupling between the high-lying acoustic branch and the low-lying optical branch, further impeding phonon diffusion. The calculations reveal that grain boundaries also contribute to the low lattice thermal conductivity of KCdSb through medium-frequency phonon scattering. These combined factors create a glass-like thermal transport behavior, which is advantageous for improving the thermoelectric merit of zT. Notably, a maximum zT of 0.6 is achieved for K0.84Na0.16CdSb at 712 K. The study offers both intrinsic and extrinsic strategies for developing high-efficiency thermoelectric Zintl materials with extremely low lattice thermal conductivity.

High Ductility and Excellent Thermoelectric Performance in Te-Stabilized Cubic Ag2TexS1-x Solid Solutions.

The stabilization at low temperatures of the Ag2S cubic phase could afford the design of high-performance thermoelectric materials with excellent mechanical behavior, enabling them to withstand prolonged vibrations and thermal stress. In this work, we show that the Ag2TexS1-x solid solutions, with Te content within the optimal range 0.20 ≤ x ≤ 0.30, maintain a stable cubic phase across a wide temperature range from 300 to 773 K, thus avoiding the detrimental phase transition from monoclinic to cubic phase observed in Ag2S. Notably, the Ag2TexS1-x (0.20 ≤ x ≤ 0.30) samples showed no fractures during bending tests and displayed superior ductility at room temperature compared to Ag2S, which fractured at a strain of 6.6%. Specifically, the Ag2Te0.20S0.80 sample demonstrated a bending average yield strength of 46.52 MPa at 673 K, significantly higher than that of Ag2S, whose bending average yield strength dropped from 80.15 MPa at 300 K to 12.66 MPa at 673 K. Furthermore, the thermoelectric performance of the Ag2TexS1-x (0.20 ≤ x ≤ 0.30) samples surpassed that of both InSe and pure Ag2S, with the Ag2Te0.30S0.70 sample achieving the highest ZT value of 0.59 at 723 K. These results indicate substantial potential for practical applications due to enhanced durability and thermoelectric performance.

High In-Plane Thermoelectric Performance of Layered Bi4O4SeCl2.

The van der Waals semiconductor Bi4O4SeCl2 has recently attracted great interest due to its extremely small lattice thermal conductivity, which may find possible application in the field of energy conversion. Herein, we accurately predict the thermoelectric transport properties of Bi4O4SeCl2 using first-principles calculations and Boltzmann transport theory, where the carrier relaxation time is obtained by fully considering the electron-phonon coupling. It is found that a maximum p-type ZT value of 3.1 can be reached at 1100 K along the in-plane direction, which originates from increased Seebeck coefficient induced by multivalley band structure, as well as enhanced electrical conductivity caused by relatively stronger intralayer bonding. Besides, it is interesting to note that comparable p- and n-type ZT values can be realized in certain temperature regions, which is very desirable in the fabrication of thermoelectric modules.

Thermoelectric Performance Enhancement in SnS Polycrystals Owing to Hole Doping Combined with Textured Microstructures.

Recently, the earth-abundant tin sulfide (SnS) has emerged as a promising thermoelectric material due to its phonon and electron structure similar to that of tin selenide (SnSe). However, compared with SnSe, limited progress has been achieved in the thermoelectric property enhancement of SnS. Textured SnS polycrystals with an enhanced thermoelectric performance have been developed in this work. The high carrier mobility benefited from the enhanced texture through the repressing strategy of spark plasma sintering, improving the electrical conductivity. In addition, Sn atom deficiencies in the texture sample led to an increased hole concentration, further boosting the electrical conductivity and power factor. The power factor exceeded 4.10 µW/cm·K2 at 423 K and 5.50 µW/cm·K2 at 850 K. The phonon scattering was strengthened by adjusting the multiscale microstructures including dislocations, defect clusters, etc., leading to an ultralow lattice thermal conductivity of 0.23 W/m·K at 850 K. A figure of merit zT > 1.3 at 850 K and an average zTave of 0.58 in the temperature range 373-850 K were achieved in the SnS polycrystal.

Probing the opto-electronic, phonon spectrum, and thermoelectric properties of lead-free fluoride perovskites A2GeSnF6 (A = K, Rb, Cs) for energy harvesting devices.

The present work employs density functional theory to explore the structural, optoelectronic, and thermoelectric attributes of the halide-based double perovskite A2GeSnF6 (A = K, Rb, and Cs) compounds. The stable phonon dispersion spectrum affirms dynamical stability, whereas the enthalpy of formation and tolerance factor evaluated collectively verify structural stability. Considering the Tran Blaha modified Becke Johnson potentials (mBJ), the predicted direct band gaps along the symmetry point are 3.19 eV for K2GeSnF6, 3.16 eV for Rb2GeSnF6 and 3.12 eV Cs2GeSnF6. According to an in-depth examination of the optoelectronic features, A2GeSnF6 (A = K, Rb, and Cs), double perovskites are assuring contenders for optoelectronic devices due to their suitable bandgap. The extremely high figure of merit values (0.94-0.97) obtained from the numerical calculation of power factor and thermal conductivity suggest the intriguing prospects of these compositions for thermoelectric devices. These studies offer a perceptive comprehension of the materials for their potential applications in the future.

Significant Improvement in Thermoelectric Properties of Carbon-Reinforced Cementitious Composites Achieved by Regulating the Graphitization Degree of Expanded Graphite.

Building structures are exposed to direct sunlight for a long time, accumulating a large amount of low-grade thermal energy, which aggravates environmental pollution and energy consumption. Thermoelectric cement-based composites can realize the interconversion of thermal and electrical energy, showing great potential benefits in large-scale heat collection and energy conversion. Although a lot of exploration and research has been carried out on the thermoelectric properties of cement-based composites reinforced with carbon materials, the contribution of the characteristics of carbon materials, such as the graphitization degree, to the thermoelectric properties of cement-based composites is still unclear. In this article, the graphitization degree of expanded graphite (EG) was modulated by etching EG with an acid solution. The low graphitization degree improves the effective mass of carriers and aggravates the electron and phonon scattering at the interface of EG/cement-based composites. Low thermal conductivity was obtained while increasing the Seebeck coefficient of EG/cement-based composites. The power factor (17.1 µW m-1 K-2) and thermoelectric figure of merit (2.95 × 10-3) of the sample are increased by 18.6 times and 44.2 times, respectively, achieving the highest thermoelectric performance in cement-based composites reinforced with carbon materials. This study provides a direction for improving the thermoelectric properties of cement-based composites by structural regulation of carbon materials.

Mg-Defect Compensation to Realize High Performance at Room Temperature in Mg3Bi2-Based Thermoelectric Single Crystals.

Mg3Bi2-based materials are a very promising substitute for current commercial Bi2Te3 thermoelectric alloys. The successful growth of Mg3Bi2-based single crystals with high room-temperature performance is especially significant for practical applications. Previous studies indicated that the effective suppression of Mg defects in Mg3Bi2-based materials was crucial for high performance, which was usually realized by applying excessive Mg during syntheses. However, utilization of excessive Mg generates Mg-rich phases between the crystalline boundaries and is unfavorable for the long-term stability of the materials. Here, bulk single crystals with a low-content Mg component such as Mg3.1Bi1.49Sb0.5Te0.01 were successfully grown. For compensating Mg defects, Li was chosen as the additional electron dopant. The results indicate that Li is a very effective electron compensator when low-concentration doping is applied. For high-concentration doping, Mg atoms in the lattice are substituted by Li, leading to decreased electron concentration again. This strategy is very significant for improving the room-temperature performance of Mg3Bi2-based materials. As a result, a record-high figure of merit of 1.05 at 300 K is achieved for Mg3+xLi0.003Bi1.49Sb0.5Te0.01 single crystals.

Investigation into the physical characteristics of the compounds XBiSe2 (X = Li, Na or K).

CONTEXT: As new materials, the ternary chalcogenides have recently brought scientists' attention. These materials are a novel class of semiconducting chemical compounds. They allow the increase of the photo-conversion efficiency, the performance, and the cheap energy cost. Such materials also provide a wide range of physical and chemical applications. METHODS: The used investigation employs Density Functional Theory (DFT) implemented in the Wien2k package to systematically characterize the physical properties of ternary chalcogenide compounds XBiSe2 (X = Li, Na and K). Such method emphasizes their applicability to energy conversion technologies. Scrutinizing their electronic, optical, and thermoelectric properties elucidates the effect of alkali metal substitution on performance metrics. The results not only advance knowledge of these materials' physicochemical behaviors but also reveal their potential for tailored functionalization in next-generation energy and optoelectronic systems, marking a significant stride in material science and application-oriented research.

Grain boundary, electrical transport and thermoelectric properties of the ultra-high rGO amount of C12A7-rGO composites.

The Ca12Al14O33 ceramic (C12A7) and reduced graphene oxide (rGO) composite which an ultra-high amount (i.e., 40, 50, 60, and 70 wt%) of rGO (ultra-high amount C12A7/rGO composite) were synthesized by a solid-state reaction process. After the hydraulic press, the heat treatment in the temperature range of 773 K under the argon environment had been performed with the composite pellets for 30 min. XRD results of the C12A7 and all the ultra-high amount C12A7/rGO composites indicated a pure phase of C12A7 ceramic. Raman spectra confirmed the existence of rGO content in all the ultra-high amount C12A7/rGO composites. Raman peaks also suggested reduction of the free O22- and O2- ions from the framework of the ultra-high amount C12A7/rGO composites. SEM image presented the homogeneous grain boundary interface after the heat treatment at 773 K of the C12A7 wrapped by the rGO sheet, the agglomerated rGO sheet, and the rough interface stack of rGO sheets. UV-VIS spectroscopy presented the absorption behavior, direct energy gap, and indirect energy gap modifications of the ultra-high amount C12A7/rGO composites. Electrical conductivity of the ultra-high amount C12A7/rGO composites illustrated larger than 108 times improvement with temperature independence. Range of -5 to -17 µV/K , temperature dependence, and increased with rGO content increasing Seebeck coefficient were reported. Thermal conductivity of the ultra-high amount C12A7/rGO composites was increased with the rGO content increasing. Both the Power factor (PF) and the figure of merit (ZT) of the ultra-high amount C12A7/rGO composites were temperature dependent and were increased with the rGO content increasing, within the range of 0.4 µW/m.K2 of PF and the range of 3x10-4 of ZT, respectively. These experimental results verified grain boundary, modified energy band, electrical transport properties and thermoelectric properties of C12A7/rGO composites loading with ultra-high content rGO.

High-performance optoelectronic and thermoelectric properties of transparent conductors based on Tl2O3 under pressure.

In this work, the full-potential linearized augmented plane wave method (FP- LAPW) and the modified Becke-Johnson (mBJ) functional with spin-orbit (SO) coupling are used the obtain the structural, optoelectronic and thermoelectric properties of Tl2O3 under pressure. The results show that Tl2O3, as transparent conducting oxide (TCO), is a direct bandgap semiconductor with a band gap of 1.23 eV. The band gap value and the effective mass of electrons increases by increasing pressure. Density of state spectra reveal that the nature of electrons in Tl-6s state in the bottom of conduction band, like free electrons in s state, is responsible for the conducting behavior of Tl2O3. A blue shift is observed in optical spectra such as electron energy loss and absorption spectra with an increase in pressure. Obtained dielectric constants under pressure are inversely proportional to the band gap value according to Penn model. The effects of pressure on thermometric properties are also explored. The hydrostatic pressure increases Seebeck coefficient, while it decreases thermal conductivity that is an effective way to the enhancement of the thermoelectric efficiency of TCOs. A figure of merit (ZT) of 0.98 in p-type Tl2O3 is achieved that is desirable for using in thermoelectric devices.

High-resolution scanning tunneling microscope and its adaptation for local thermopower measurements in 2D materials.

We present the design, fabrication and discuss the performance of a new combined high-resolution Scanning Tunneling and Thermopower Microscope (STM/SThEM). We also describe the development of the electronic control, the user interface, the vacuum system, and arrangements to reduce acoustical noise and vibrations. We demonstrate the microscope's performance with atomic-resolution topographic images of highly oriented pyrolytic graphite (HOPG) and local thermopower measurements in the semimetal Bi2Te3. Our system offers a tool to investigate the relationship between electronic structure and thermoelectric properties at the nanoscale.

Ab-initiotransport model to study the thermoelectric performance of MoS2, MoSe2, and WS2monolayers by using Boltzmann transport equation.

The potential for thermoelectric applications of two-dimensional materials is quite promising. Usingab-initiocalculations, we have investigated the electronic band structure, phonon band structure, electronic density of states, and phonon density of states of monolayers MoS2, MoSe2, and WS2. In order to compute the thermoelectric properties of monolayers MoS2, MoSe2, and WS2, we used theab-initiomodel suggested by Faghaniniaet al(2015Phys. Rev.B91235123). Within this model, by using inputs from density functional theory and considering all relevant elastic and inelastic scattering mechanisms, we have calculated the thermoelectric properties of monolayers MoS2, MoSe2, and WS2over various ranges of temperature (T) and carrier concentration (n). The obtained results of Seebeck coefficients (S) and figure of merit (ZT) atT= 300 K for bothn/p-types of monolayers MoS2, MoSe2, and WS2are in good agreement with the findings obtained by other models using the Boltzmann transport equation within a constant relaxation time framework.

Rapid low-temperature densification of Ag2Se bulk material: mass transfer through the dissociative adsorption reaction of Ag protrusions and Se saturated vapor.

In materials science, the impact of density on a material's capabilities is profound. Conventional sintering requires high temperatures and is energy-demanding, propelling the pursuit of less intensive, low-temperature densification methods. Electric field-assisted sintering has recently gained attention for its simplicity and effectiveness, offering a new frontier in low-temperature densification. In this study, dense bulk materials were produced by subjecting monophasic Ag2Se powders to electric field-assisted sintering, where a direct current with an average value of 4 A was applied, achieving a peak temperature of 344 K. The novel low-temperature densification mechanism unfolds thus: nanoscale silver protrusions, stimulated by electrical current, engage in a dissociative adsorption reaction with the ambient saturated selenium vapor. This process swiftly engenders the formation of fresh silver selenide (Ag2Se) compounds, initiating nucleation and subsequent growth. Consecutively, these compounds seamlessly occupy and expand, perpetually bridging the interstices amidst the powders. In a scant 8 s, the density swiftly surpassed 99%, yielding a bulk material that exhibited aZTvalue of 1.07 at 390 K. This investigation not only attains an unparalleled density at low temperatures but also charts a pioneering course for material densification in such conditions.

Investigating the physical and optoelectronic characteristics of Co2ZrZ compounds: findings from computational analysis and thermoelectric evaluation.

CONTEXT AND RESULTS: The study examines the physical characteristics of Co2ZrZ compounds using the Wien2k code and the Anisimov and Gunnarsson approach. Results show metallic attributes in Co2ZrBi and Co2ZrAs, while Co2ZrPb exhibits semi-metallic tendencies. Energy gap evaluations reveal significant infrared transitions, indicating altered electron mobility compensated by increased ultraviolet absorption. These compounds have potential in space solar energy applications due to UV light absorption capabilities, especially in Co2ZrPb. The study also identifies optical phenomena like "super-luminescence" and plasmatic oscillations. COMPUTATIONAL AND THEORETICAL TECHNIQUES: The study uses computational techniques like Wien2k calculation code and Hubbard parameter calculations to investigate Co2ZrPb, a compound with potential for space energy applications. Energy gap assessments are conducted using GGA and mBJ-GGA methods. The study also analyzes the optical behavior of the compounds, including infrared and ultraviolet absorption. The BoltzTraP code is used for thermoelectric investigations, revealing a P-type charge carrier predominance in Co2ZrPb. This comprehensive approach provides valuable insights into electrical conductivity and thermoelectric properties.

Thermoelectric Properties of Zn-Doped YbMg1.85-xZnxBi1.98.

Bi-based YbMg2Bi1.98 Zintl compounds represent promising thermoelectric materials. Precise composition and appropriate doping are of great importance for this complex semiconductor. Here, the influence of Zn substitution for Mg on the microstructure and thermoelectric properties of p-type YbMg1.85-xZnxBi1.98 (x = 0, 0.05, 0.08, 0.13, 0.23) was investigated. Polycrystalline samples were prepared using induction melting and densified with spark plasma sintering. X-ray diffraction confirmed that the major phase of the samples possesses the trigonal CaAl2Si2-type crystal structure, and SEM/EDS indicated the presence of minor secondary phases. The electrical conductivity increases and the lattice thermal conductivity decreases with more Zn doping in YbMg1.85-xZnxBi1.98, whereas the Seebeck coefficient has a large reduction. The band gap decreases with increasing Zn concentration and leads to bipolar conduction, resulting in an increase in the thermal conductivity at higher temperatures. Figure of merit ZT values of 0.51 and 0.49 were found for the samples with x = 0 and 0.05 at 773 K, respectively. The maximum amount of Zn doping is suggested to be less than x = 0.1.

Crucial Role of Ni Point Defects and Sb Doping for Tailoring the Thermoelectric Properties of ZrNiSn Half-Heusler Alloy: An Ab Initio Study.

In the wide group of thermoelectric compounds, the half-Heusler ZrNiSn alloy is one of the most promising materials thanks to its thermal stability and narrow band gap, which open it to the possibility of mid-temperature applications. A large variety of defects and doping can be introduced in the ZrNiSn crystalline structure, thus allowing researchers to tune the electronic band structure and enhance the thermoelectric performance. Within this picture, theoretical studies of the electronic properties of perfect and defective ZrNiSn structures can help with the comprehension of the relation between the topology of defects and the thermoelectric features. In this work, a half-Heusler ZrNiSn alloy is studied using different defective models by means of an accurate Density Functional Theory supercell approach. In particular, we decided to model the most common defects related to Ni, which are certainly present in the experimental samples, i.e., interstitial and antisite Ni and a substitutional defect consisting of the replacement of Sn with Sb atoms using concentrations of 3% and 6%. First of all, a comprehensive characterization of the one-electron properties is performed in order to gain deeper insight into the relationship between structural, topological and electronic properties. Then, the effects of the modeled defects on the band structure are analyzed, with particular attention paid to the region between the valence and the conduction bands, where the defective models introduce in-gap states with respect to the perfect ZrNiSn crystal. Finally, the electronic transport properties of perfect and defective structures are computed using semi-classical approximation in the framework of the Boltzmann transport theory as implemented in the Crystal code. The dependence obtained of the Seebeck coefficient and the power factor on the temperature and the carrier concentration shows reasonable agreement with respect to the experimental counterpart, allowing possible rationalization of the effect of the modeled defects on the thermoelectric performance of the synthesized samples. As a general conclusion, defect-free ZrNiSn crystal appears to be the best candidate for thermoelectric applications when compared to interstitial and antisite Ni defective models, and substitutional defects of Sn with Sb atoms (using concentrations of 3% and 6%) do not appreciably improve electronic transport properties.

C 3 N based heterobilayers: a potential platform to explore optoelectronic and thermoelectric properties.

We theoretically investigate the full thermal transport and optoelectronic features of two estab- lished van der Waals (vdW) heterostructures based on the recently synthesized monolayer of C 3 N using the machinery of the Boltzmann transport and GW+BSE calculations. Among the structures, C 3 N/hBN tends to exhibit a small indirect gap semiconducting nature with an admixture of com- paratively higher 'flat-and-dispersiveness' and band degeneracy in the conduction band minima. A nearly comparable high thermoelectric power factor is observed for both the charge carriers at 300 K and 900 K at specific concentrations. The other material, C 3 N/graphene however maintains a low Seebeck coefficient with large electrical conductivity which correctly manifests its metallic character. A combination of low atomic mass, higher anharmonicity and longer lifetime of acous- tic phonons in C 3 N/hBN results in an intermediate lattice thermal conductivity (196 Wm -1 K -1 ) at room temperature as compared to its constituent monolayers. Under heavy n-type doping, C 3 N/hBN hetero-bilayer displays a figure of merit value of 0.13 (and 0.36) at room temperature (and at 900 K). As per the optical signatures are concerned, C 3 N/hBN reveals two distinct absorp- tion peaks with a high electron-hole quasiparticle interaction energy correction. Besides both the structures display a much better absorption throughout the spectrum compared to graphene. We expect these findings will motivate future research in designing thermoelectric and optoelectronic materials made of light mass, earth-abundant and non-toxic elements.

N-DMBI Doping of Carbon Nanotube Yarns for Achieving High n-Type Thermoelectric Power Factor and Figure of Merit.

The application of carbon nanotube (CNT) yarns as thermoelectric materials for harvesting energy from low-grade waste heat including that generated by the human body, is attracting considerable attention. However, the lack of efficient n-type CNT yarns hinders their practical implementation in thermoelectric devices. This study reports efficient n-doping of CNT yarns, employing 4-(1, 3-dimethyl-2, 3-dihydro-1H-benzimidazole-2-yl) phenyl) dimethylamine (N-DMBI) in alternative to conventional n-dopants, with o-dichlorobenzene emerging as the optimal solvent. The small molecular size of N-DMBI enables highly efficient doping within a remarkably short duration (10 s) while ensuring prolonged stability in air and at high temperature (150 °C). Furthermore, Joule annealing of the yarns significantly improves the n-doping efficiency. Consequently, thermoelectric power factors (PFs) of 2800, 2390, and 1534 µW m-1 K-2 are achieved at 200, 150, and 30 °C, respectively. The intercalation of N-DMBI molecules significantly suppresses the thermal conductivity, resulting in the high figure of merit (ZT) of 1.69×10-2 at 100 °C. Additionally, a π-type thermoelectric module is successfully demonstrated incorporating both p- and n-doped CNT yarns. This study offers an efficient doping strategy for achieving CNT yarns with high thermoelectric performance, contributing to the realization of lightweight and mechanically flexible CNT-based thermoelectric devices.

Structural, electronic and thermoelectric properties of monolayer TiSe2.

CONTEXT AND RESULTS: In this work the first-principles calculations of the structural, electronic and thermoelectric properties of monolayer TiSe2 are presented. The optimized lattice parameter of monolayer TiSe2 shows excellent agreement with the experimental value. The computed band structure and density of states calculations predict metallic nature of monolayer TiSe2 with overlapping of 0.44 eV between the lowest conduction band and top valance band at high symmetry point M. The position of pseudogap formed by Ti-3d orbitals near the Fermi level confirms the mechanical stability of monolayer TiSe2. Due to the influence of positive strain (tensile strain), the Ti-Se bond length increases and the layer height decreases. The applied tensile strain changes the metallic nature of TiSe2 into a semiconductor with opening of bandgap. It has also been observed that the positions of conduction band minima and valance band maxima change with strain. The charge analysis shows that charge transfer from Ti to Se atom increases when tensile strain is applied, while an opposite trend is observed with compression. The computed thermoelectric coefficients i.e. Seeback coefficient, power factor and figure of merit are in good agreement with the experimental data. The temperature dependence of these coefficients is also reported. COMPUTATIONAL METHOD: The density functional theory based calculations are reported employing the PBE-GGA ansatz using the plane wave-pseudopotential method embodied in the Quantum ESPRESSO package. The self-consistent field calculations are performed over a dense Monkhorst-Pack net of 12 × 12 × 1 k-points. The energy convergence criteria for the self-consistent field calculation were set to 10-6 Ry/atom with a cutoff energy of 90 Ry. The thermoelectric properties are computed by combining the band structure calculations with the Boltzmann transport equation using Boltztrap2 peckage.