Scalable solution chemical synthesis and comprehensive analysis of Bi2Te3 and Sb2Te3
0 
Abstract
Thermoelectric (TE) materials can directly convert heat into electrical energy. However, they sustain costly production procedures and batch-to-batch performance variations. Therefore, developing scalable synthetic techniques for large-scale and reproducible quality TE materials is critical for advancing TE technology. This study developed a facile, high throughput, solution-chemical synthetic technique. Microwave-assisted thermolysis process, providing energy-efficient volumetric heating, was used for the synthesis of bismuth and antimony telluride (Bi2Te3, Sb2Te3). As-made materials were characterized using various techniques, including XRPD, SEM, TEM, XAS, and XPS. Detailed investigation of the local atomic structure of the synthesized Bi2Te3 and Sb2Te3 powder samples was conducted through synchrotron radiation XAS experiments. Radial distribution functions around the absorbing atoms were reconstructed using reverse Monte Carlo simulations, and effective force constants for the nearest and distant coordination shells were subsequently determined. The observed differences in the effective force constants support high anisotropy of the thermal conductivity in Bi2Te3 and Sb2Te3 in the directions along and across the quintuple layers in their crystallographic structure. The as-made materials were consolidated via Spark Plasma Sintering to evaluate thermal and electrical transport properties. The sintered TE materials exhibited low thermal conductivity, achieving the highest TE figure-of-merit values of 0.7 (573 K) and 0.9 (523 K) for n-type Bi2Te3 and p-type Sb2Te3, respectively, shifted significantly to the high-temperature region when compared to earlier reports, highlighting their potential for power generation applications. The scalable, energy- and time-efficient synthetic method developed, along with the demonstration of its potential for TE materials, opens the door for a wider application of these materials with minimal environmental impact.
Keywords
INTRODUCTION
The fast-changing and ever-increasing global energy demand has resulted in various fossil fuel-related environmental challenges, necessitating the development of renewable, affordable, and efficient energy supplies and energy-harvesting strategies[1-3]. Thermoelectric (TE) materials and devices can directly interconvert between heat and electrical power, which could contribute to energy generation, utilization, and environmental impact[3,4]. Based on the two fundamental phenomena, Seebeck and Peltier effects, TE devices may function as TE generators (TEGs) for harvesting heat energy or as coolers (TECs)[1,5]. TE materials-based technologies can be employed in various applications, including medical and wearable devices, low-power devices such as the Internet of Things (IoT), on-chip cooling, self-powering gadgets, solar cells, battery-free sensors, and space missions[1,5,6]. Thermal energy can be harvested from different low-grade heat sources, such as cars, buildings, electronic equipment, and the human body.
Unlike conventional electricity-generating technologies, TE devices function without the contribution of mechanical energy, making them reliable. They can operate under wide working temperature ranges without vibrations and noise, are easy to maintain, and have extended operational lifetime, among their attractive features[6-8]. However, low conversion efficiency, manufacturing challenges, complexity, and materials costs of this technology hinder its broad application[9,10]. The dimensionless TE figure of merit (ZT), expressed as ZT = S2σT/κ, describes the efficiency of a TE material, where σ is the electrical conductivity, S is the Seebeck coefficient, T is the absolute temperature, and κ is the thermal conductivity[10-12]. The formula suggests that an ideal TE is a “phonon glass electron crystal”, allowing charge carriers to flow freely (high σ) while maintaining a temperature difference across the material (low thermal conductivity)[10,13]. In addition, the material's band structure is critical for maintaining the thermal voltage (high S)[9,13]. Therefore, semiconductor materials, in general, are favorable as TE materials. However, since S, σ, and κ have an inherent correlation in classical materials, improving the ZT has been challenging[14-16]. One of the crucial strategies to enhance the ZT is based on increasing phonon scattering through nanostructuring[17], producing nanoprecipitates[18], porosity design[19], alloying, and grain boundary engineering[20,21]. So far, numerous research efforts based on theoretical predictions and experimental explorations have shown that nanostructuring could considerably improve the performance of TE materials by lowering the negative correlation of TE transport characteristics. Due to a large density of interfaces (point defects/grain boundaries) in nanostructures, phonons are scattered more efficiently than electrons, since the mean free paths of heat carriers are longer than those of charge carriers. This results in a reduction in κ (based on the phonon-blocking effect) while not considerably affecting the mobility of charge carriers[22,23]. Moreover, based on the quantum confinement phenomena, nanostructuring may widen the band gap and discretization in the electronic density of states, enhancing the S[13,17].
TE materials are categorized into three groups based on their operational temperature range: ambient, mid- and high-temperature. The band gap and chemical stability of these materials determine the feasibility of a given composition as a TE material. Most of the generated waste heat is attributed to temperatures below 200 °C, referred to as low-temperature waste heat. However, capturing and reusing low-grade waste heat is challenging since it has low energy density[24]. Binary and ternary metal chalcogenides perform well in this temperature range, with bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) (and their alloys) being the two most popular n- and p-type TE materials with high ZT, operation around room temperature, effective up to 200 °C due to their specific band structure, high carrier mobility, and intrinsically low κ[23].
TE materials have been synthesized through commonly used synthetic techniques, such as solid-state, gas-phase, and wet chemical routes. Each method has its constraints and advantages, leading to materials with different microstructures. Zone melting has long been the mainstream fabrication technique for the fabrication of commercial bismuth-telluride-based solid solutions[26]. Strategies for synthesizing nanostructured Bi2Te3 and Sb2Te3 include mechanical alloying[27], physical vapor deposition[28], chemical reduction[29], hydrothermal[3], solvothermal[30], and thermolysis[17,31,32] routes. Different morphologies of
EXPERIMENTAL
Materials
Bismuth chloride (BiCl3, 98% purity), Antimony chloride (SbCl3, 99.95% purity), Tellurium powder (Te, 99.8% purity), Oleic acid (C18H34O2), 1-Octadecene (C18H36, ODE), thioglycolic acid (C2H4O2S, 98%, TGA), tri-butyl phosphine (C12H27P, 93.5%, TBP), acetone and isopropanol were all purchased from Sigma Aldrich (Stockholm, Sweden) and used as received without further purification. All chemicals were of analytical grade.
Synthesis of nanostructured Bi2Te3 and Sb2Te3 powders
The synthesis was performed using a MW-assisted thermolysis method. To achieve the desired Bi2Te3 and Sb2Te3 compounds, stoichiometric amounts of each precursor were used to maintain a 2:3 molar ratio for Bi:Te and Sb:Te. The Te powder was first complexed with TBP (6 mL) by heating the mixture at 220 °C, using MW power of 400 W under constant stirring using a MW synthesizer (Biotage® Initiator+), until all the Te powder was fully dissolved. Meanwhile, in a separate vial, a precursor solution of Bismuth (or Antimony) was prepared by dissolving a stoichiometric amount of BiCl3 (or SbCl3) in Oleic acid under continuous stirring for 30 min. The solution was then transferred to a 100 mL Teflon vessel, where ODE
Figure 1. Schematics of the MW-assisted thermolysis synthesis of Bi2Te3 and Sb2Te3.
Eventually, the mixture was heated by MW (1800 Watt; flexiWAVE-Milestone, high-pressure multivessel rotor) to the reaction temperature of 220 °C with 4 min ramp time and 2 min dwell time (see
Consolidation using spark plasma sintering
The powders obtained by the MW-assisted thermolysis method were loaded into a graphite die (Ф 15 mm), with top and bottom graphite punches, and sintered by Spark Plasma Sintering (SPS, Dr. Sinter 825, Fuji Electronic Industrial Co. Ltd., Tokyo, Japan) to form nanostructured pellets. The sintering process was performed at 400 °C under 70 MPa with a heating rate of 30 °C/min and a holding time of 5 min for both samples. During the cooling process from 400 °C to room temperature, the load was reduced from 70 to
Structural, morphological, and surface characterization
X-ray powder diffraction analysis
X-ray powder diffraction (XRPD) analysis was accomplished using a Philips PANalytical X'Pert Pro Powder Diffractometer, equipped with copper anode (Cu-Kα1 radiation,
The particle size and morphology of the sample were studied using scanning electron microscopy (SEM, FEI Nova 200, Hillsboro, OR, USA). The SEM samples were fixed on the holder using graphene ink or copper tape, to avoid charging and enhance the image resolution. Transmission electron microscopy (TEM, JEM-2100F, 200 kV, JEOL Ltd. Tokyo, Japan) analysis was performed on the as-prepared nanopowders to investigate the crystallinity of the samples. Samples were made by drop casting a 200 μL aliquot of nanoparticle suspension in isopropanol on copper TEM grids and drying them in air.
X-ray absorption spectroscopy analysis
Temperature-dependent X-ray absorption spectroscopy (XAS) measurements of Bi2Te3 and Sb2Te3 samples were performed at DESY PETRA III P65 Applied XAS beamline[37]. The PETRA III storage ring operated at
X-ray photoelectron spectroscopy analysis
Surface chemical composition of the synthesized materials has been examined using the X-ray photoelectron spectroscopy (XPS) technique. The non-monochromatized X-ray source with a Mg anode lamp (Mg Kα line, 1,253.6 eV) was used in all analyses. High-resolution photoelectron energy spectra were recorded with Auger Electron Spectroscopy (AES)/XPS system EA10 (Leybold-Heraeus GmbH, Cologne, Germany) at room temperature, under the pressure less than 5 × 10-8 mbar. The spectrometer energy scale was calibrated using Au 4f, Ag 3d, and Cu 2p lines, and all acquired spectra were calibrated to the adventitious carbon C 1s line at 285 eV. The overall resolution of the spectrometer during the measurements was estimated as 0.96 eV, using the full width of half maximum (FWHM) of the Ag 3d5/2 line. The data acquisition was done using WSpectra version 8 (R. Unwin, 2001) software, and data processing (deconvolution) was performed using CasaXPS software version 2.3 (Casa Software Ltd., Teignmouth, U.K.). A wide-range energy scan was collected to determine surface chemical composition, based on which the high-resolution scans of elemental emission lines were performed. The atomic concentration in the sample was determined through XPS spectral analysis, considering the presence of each element.
Electrical and thermal transport property evaluations
The TE transport measurements were conducted on SPS compressed pellets. The total thermal conductivity κtot was estimated using κtot = Cp·α·ρ, where Cp is the specific heat capacity, α is thermal diffusivity, and ρ is the density of mass. Cp measurements were performed via Differential Scanning Calorimetry (DSC, PT1000 Linseis). The α was measured on 2 mm thick disk-shaped samples (see Supplementary Figure 3 for sample geometry) using the laser flash analysis (LFA 1000, Linseis) system. σ and S measurements were performed simultaneously using the commercial ZEM3 ULVAC-RIKO system. A percentage error of 5%-10% is possible in calculating the thermal conductivity of Bi2Te3 and Sb2Te3 pellets using the laser flash method and can vary due to several factors, including sample quality and measurement precision[38,39].
Data analysis by reverse Monte Carlo simulations
Experimental extended X-ray absorption fine structure (EXAFS) spectra were extracted from X-ray absorption spectra using the XAESA code[40], following the conventional procedure[41]. The analysis of EXAFS spectra employed the RMC method based on the evolutionary algorithm (RMC/EA) implemented in the EvAX code[42,43]. The RMC method is an atomistic simulation approach that iteratively minimizes the difference between experimental and calculated EXAFS spectra, making random atomic displacements within the structure model of the material.
In this study, an initial structure model was constructed for each temperature point based on lattice parameters from the neutron diffraction data[44]. A supercell (4a × 4b × 3c) containing 720 atoms with periodic boundary conditions was used for calculations. The RMC/EA calculations were performed for 32 atomic configurations simultaneously. At each iteration, all atoms in the supercell were randomly displaced with a maximum allowed shift of 0.4 Å. The configuration-averaged EXAFS spectra were calculated using the ab initio self-consistent real-space multiple-scattering (MS) FEFF8.5L code[45,46], considering contributions from single, double, and triple scatterings. The complex energy-dependent exchange-correlation Hedin-Lundqvist potential was employed to account for inelastic effects[47]. The amplitude scaling parameter is set to 1. Good agreement between experimental and simulated data was achieved in both k- and R-spaces simultaneously for two absorption edges (Sb/Bi and Te). This was demonstrated by comparing the Morlet wavelet transform (WT) of the respective EXAFS[48]. RMC/EA calculations for Bi2Te3 and Sb2Te3 were performed in the k-space range of 3.0-15.4 Å-1 and the R-space range from 2 to 7.0-7.6 Å for both (Sb/Bi and Te) metal edges. Note that such a wide range in R-space allows one to determine the partial radial distribution functions (RDFs) g(r) of up to about 8 Å. The convergence of each RMC simulation was achieved after several thousand iterations. Five RMC/EA simulations with different sequences of pseudo-random numbers were performed for each experimental data set. As a result of simulations, 3D structure models of the tellurides were obtained at each temperature point and used to calculate the partial RDFs g(r) and the average interatomic distances and the mean-square relative displacement (MSRD) factors, also known as the Debye-Waller factors. The temperature dependencies of the MSRD factors for the nearest and distant coordination shells were further utilized to estimate the effective force constants (f).
RESULTS AND DISCUSSION
Structural analysis
Through MW-assisted thermolysis, it has been possible to synthesize nanostructured materials in an energy and time-efficient manner. The synthesis process took about 6 min, with a reaction yield of 98%. Structural analysis was performed using XRPD on as-synthesized powders, and after their sintering using SPS. The diffraction patterns of as-made and sintered samples are presented in Figure 2, where the diffraction patterns are normalized for the most intense diffraction indexed to the (015) plane. For the sintered pellet samples, the XRPD analysis was conducted on the surface perpendicular to the sintering direction. The crystalline phases are identified as Sb2Te3 (ICDD: 96-900-7591) and Bi2Te3 (ICDD: 01-085-0439), both exhibiting a rhombohedral crystal structure. The Bragg diffraction peaks have been indexed with the appropriate Miller indices, as displayed on the diffraction patterns in Figure 2. When comparing the sintered samples with as-made samples, it is evident that sintered samples have more intense Bragg diffraction peaks corresponding to the same Miller indices of (006), (1010), (0015), and (1016), indicating a higher crystallinity. Following sintering, a significant increase in the relative intensity of the diffraction peaks with the (00l) index is observed, in comparison to the dominant (015) peak, indicating a high level of texturing in both samples. The ratio of intensity of the (006) peak to (015) peak can be used to assess the degree of texturing. After the SPS process, the c-axis of the grains aligned parallel to the pressing direction, leading to a greater degree of texturing in the case of Bi2Te3.
Figure 2. X-ray powder diffraction (XRPD) patterns of as-synthesized and sintered Bi2Te3 (A) and Sb2Te3 (B) samples. The major crystalline phases are indexed to Bi2Te3 (ICDD: 01-085-0439) and Sb2Te3 (ICDD: 96-900-7591), with rhombohedral crystal structure.
Microstructure analysis
Microstructure and morphology analyses for as-made powder and sintered samples as pellets have been performed using SEM. Micrographs at different magnifications for Bi2Te3 and Sb2Te3 samples are given in Figure 3A and B. As-made nanoparticles display hexagonal platelet morphology for both samples, where
Figure 3. SEM and TEM micrographs of (A and C) as-made Bi2Te3 and (B and D) Sb2Te3 samples synthesized through MW-assisted thermolysis.
A more detailed examination was conducted using TEM analysis, and a few micrographs are presented in Figure 3C and D. The platelets show an almost perfectly single crystalline nature. Some platelets are aligned sideways, revealing the lamella-like structure along the c-axis, which display a thickness of about 1 nm. These five atomic layers (Te-Bi-Te-Bi-Te) are the QLs held together by the vdW forces.
Pellets of consolidated nanostructured materials were prepared using the SPS technique. A few SEM micrographs of consolidated samples are presented in Figure 4A-C for Bi2Te3 and Figure 4D-F for Sb2Te3 samples at different magnifications. Both samples show laterally growing grains and apparent stacking of hexagonal platelets after the sintering process, perpendicular to the c-axis, which reveals a high level of texturing. This was also observed in XRPD [Figure 2], with an increase in the intensity ratio of (006) and (015) diffraction peaks (I006/I015), especially for the Bi2Te3 sample.
Figure 4. SEM micrographs, at different magnifications, of SPS sintered Bi2Te3 (A-C) and Sb2Te3 (D-F) samples, synthesized through MW-assisted thermolysis.
XPS analysis
XPS analysis has been used to investigate the surface chemical composition of Bi2Te3 and Sb2Te3 samples. A summary of the analysis results is presented in Table 1 and graphically in Figure 5, showing that all analyzed surfaces contain a specific amount of carbon and other elements - as listed in the table. The percentages of individual carbon bonds in the two samples are comparable: C-C bond (~60%), C-O (~22%), C-O=C (~10%), and carbonate (~8%) [Figure 5C and F]. In the case of tellurium, metallic Te residues and mixtures of TeOx (TeO2 and TeO3) or Te(OH)6 were detected [Figure 5B and E]. Bi was present on the surface of
Figure 5. X-ray photoelectron spectroscopy (XPS). (A) Bi 4f, (B) Te 3d, (C) C 1s spectra of Bi2Te3; (D) Sb 3d, (E) Te 3d, and (F) C 1s spectra of Sb2Te3 samples synthesized through MW-assisted thermolysis.
XPS peak fitting for C 1s, Bi 4f, Te 3d, Sb 3d, and O 1s regions for Bi2Te3 and Sb2Te3 samples synthesized through MW-assisted thermolysis
| Sample | Binding energy [eV] | Fraction | Assignment | |
| Bi2Te3 | 285 | 70.44 | C | C-C, C=O, C-O, carbonate |
| 159 | 2.51 | Bi-O (Bi2O3) | ||
| 573 | 1.03 | Te | ||
| 575 | 0.88 | TeOx and TeO2 | ||
| 577.5 | 2.09 | TeO3, Te(OH)6 | ||
| 530 | 23.05 | O | ||
| Sb2Te3 | 285 | 72.81 | C | C-C, C=O, C-O, carbonate |
| 528.3 | 0.23 | Sb | ||
| 530 | 1.86 | Sb-Ox | ||
| 573 | 0.15 | Te | ||
| 575 | 0.8 | TeOx and TeO2 | ||
| 577.5 | 1.08 | TeO3, Te(OH)6 | ||
| 530 | 23.07 | O | ||
We have earlier reported on the surface chemistry of Bi2Te3 samples synthesized through hydrothermal and polyol routes[3]. A quick comparison of the surface chemistry of as-made Bi2Te3 through thermolysis with similar materials obtained through wet-chemical synthesis would help understand the process of inherited minute differences in surface speciation. Nanoparticles synthesized through the thermolysis route reveal a much higher content of organics (70.44% C) when compared to polyol (39.6% C) and hydrothermal
Local atomic structure and dynamics
The local atomic structure of the as-synthesized Bi2Te3 and Sb2Te3 samples was studied using XAS. Figure 6 displays the experimental EXAFS spectra χ(k)k2 of both samples and their corresponding Fourier transforms (FTs) at the Bi L3-edge and Sb/Te K-edges. At temperatures close to 300 K, the amplitude of EXAFS spectra is significantly reduced due to the large thermal disorder. Cooling down to 10 K significantly suppresses the thermal contribution that results in higher EXAFS amplitude and more pronounced FT peaks, revealing rich information on the local structure up to at least 8 Å. While the analysis of distant coordination shells is a challenging task using traditional methods, the RMC/EA method[43,50] provides a robust approach in this case. However, data analysis should be conducted cautiously, especially at elevated temperatures, where the experimental EXAFS spectra are strongly damped due to thermal disorder.
Figure 6. Temperature dependence of the experimental EXAFS spectra [χ(k)k2] and their Fourier transforms (FTs) for the Sb and Te K-edges in Sb2Te3 (A and B) and Bi L3-edge and Te K-edge in Bi2Te3 (C and D). The FTs were calculated in the k-space range of
The RMC/EA simulations resulted in good agreement between experimental and calculated EXAFS spectra in both k- and R-spaces at all temperatures for Sb2Te3 [Supplementary Figure 4A] and Bi2Te3
The atomic coordinates obtained in the RMC/EA simulations were used to calculate partial RDFs g(r) for Bi-Te, Bi-Bi, Sb-Te, Sb-Sb, and Te-Te atom pairs. The temperature dependence of RDFs g(r) is shown in Figure 7. The RDFs were evaluated as an average of five independent RMC/EA simulations to improve statistics. The first peak in RDFs g(r) corresponds to Sb(Bi)-Te2 and Sb(Bi)-Te1 atom pairs. The two contributions are split at 10 K. However, they merge, forming a broad, asymmetric peak at elevated temperatures.
Figure 7. Temperature-dependent radial distribution functions (RDFs) g(r) calculated from the results of RMC/EA simulations for
Atomic coordinates were also used to calculate the average interatomic distances and the MSRD factors. The MSRDs were estimated using the median absolute deviation (MAD) function as described earlier[51]. The average distance within the first coordination shell [r1(M-Te2)] remains unchanged within error bars throughout the entire temperature range, measuring about 2.99 Å in Sb2Te3 and 3.07 Å in Bi2Te3. The average distance for the second coordination shell [r2(M-Te1)] increases from about 3.15 to
Temperature dependencies of the MSRD factors for the nearest Sb (Bi)-Te, Sb (Bi)-Sb (Bi), and Te-Te atom pairs in Sb2Te3 and Bi2Te3 are plotted in Figure 8, together with corresponding fits from the correlated Einstein model and estimated effective force constants. Note that data points at 300 K were excluded from the fitting procedure due to potential errors associated with the small amplitude of the experimental EXAFS spectra. The temperature dependence curves in both materials exhibit pronounced steepness that suggests relatively weak bonding between Sb, Bi, and Te atoms. Throughout all temperatures, the MSRD factor for the first coordination shell (M-Te2) consistently remains lower than that of the second coordination shell (M-Te1). Additionally, there is a notable distinction in the temperature dependencies of MSRD(M-Te2) and MSRD(M-Te1) [Figure 8D and G], arising from the fact that weak vdW forces connect two adjacent Te2 layers. At the same time, Te1 atoms are situated between two Sb (Bi) layers [Figure 8A]. The bond between M-Te2 is predominantly covalent, whereas the M-Te1 bond exhibits a combination of covalent and ionic characteristics[25].
Figure 8. Temperature dependence of the MSRD factors, determined through RMC/EA calculations for nearest Sb (Bi)-Te, Sb(Bi)-Sb(Bi), and Te-Te atom pairs in Sb2Te3 (D-F) and Bi2Te3 (G-I). Corresponding atom pairs are highlighted in panels (A-C). The solid lines represent fits using the correlated Einstein model, with the exclusion of data points at 300 K. Corresponding effective force constants
In Sb2Te3, the strength of the Sb-Te2 bond [f(r1Sb-Te2) = 24.2 ± 1.4 N/m] in the first coordination shell is notably larger than that of the Sb-Te1 bond [f(r2Sb-Te1) = 14.8 ± 0.6 N/m] in the second shell. The corresponding Einstein temperatures 116.9 ± 3.4 K and 91.3 ± 1.8 K are smaller than those (151 ± 2.4 K and 129.1 ± 3.4 K) reported for microcrystalline Sb2Te3[44]. Notably, the Sb interactions with the Te2 from the second quintile exhibit a similar strength [f(r5Sb-Te2) = 23.0 ± 1.8 N/m] as those within the first coordination shell. At the same time, the MSRD factor for the Sb-Te2 atom pair in the fifth coordination shell (r5Sb-Te2) is the largest at 10 K due to increased static disorder [Figure 8A]. Within the layers of Sb2Te3, the interactions involving the nearest Sb-Sb and Te-Te atom pairs are comparable: f(r3Sb-Sb) = 18.6 ± 0.7 N/m and
In Bi2Te3, the effective force constant for the first [f(r1Bi-Te2) = 25.7 ± 1.4 N/m] and second
Thus, we have demonstrated that the analysis of temperature-dependent X-ray absorption spectra based on atomistic simulations such as RMC method gives an access to local interatomic interactions described by effective force constants, which, in turn, affect how phonons propagate through the lattice. A lower force constant usually results in softer bonds and lower phonon frequencies, leading to lower κ, which is desirable for TEs[53]. According to interatomic force constants reported in [Figure 8D and G], the large differences in the temperature dependencies of MSRD(Sb/Bi-Te2) and MSRD(Sb/Bi-Te1) and related force constants indicate high anisotropy of the κ in Bi2Te3 and Sb2Te3 in the directions along and across the QLs in their crystallographic structure[54]. Note also that while most force constants, reported in Figure 8D-I, have close values in the two compounds, f(r5Sb/Bi-Te2) and f(r6Sb/Bi-Te2) force constants are slightly smaller in Bi2Te3.
Transport property evaluation on SPS-sintered pellets
The TE transport data for the SPS-sintered Bi2Te3 and Sb2Te3 pellets are presented in Figure 9, in the temperature interval from 300 to 575 K. It is important to note that the data obtained for the binary TE phases of Bi2Te3 and Sb2Te3 synthesized in this work are compared only with the relevant binary phases (not ternary, quaternary, or secondary phase doped solid-solutions). The secondary phases of Bi2O3, Sb2O3, and TeOx have larger band gaps than the semiconducting phases[55-57]. Based on the XRPD and XPS data, these phases are more surface-dominant. Due to their low concentration within the main matrix, they are not expected to affect electronic transport significantly. However, due to the difference in their crystal structure, the oxide phases may act as phonon scattering centers, influencing thermal conductivity.
Figure 9. Temperature-dependent electronic and thermal transport properties of SPS sintered Sb2Te3 and Bi2Te3 pellets from nanopowders synthesized through MW-assisted thermolysis route; Electrical conductivity-σ (A), Seebeck coefficient-S (B), Power factor-PF (C), Thermal conductivity-κtot (D), and the TE figure of merit ZT (E).
Figure 9A shows the σ for both Bi2Te3 and Sb2Te3, displaying a decreasing trend by increasing temperature, which is a typical behavior of metals or heavily doped semiconductors. The σ for Sb2Te3 changes from ~2,000 S/cm at 300 K to ~700 S/cm at 575 K, while it changes from ~1,750 S/cm at 300 K to ~1,000 S/cm at 575 K for Bi2Te3. A decrease in σ above 300 K typically indicates a rise in electron-phonon scattering. The σ of both samples is higher than those of other solution-derived samples and is also comparable with ingot alloy (on the level of 1,000 S/cm at 300 K)[58-60]. The high σ can be attributed to the layered structure and large-sized grains of both Bi2Te3 and Sb2Te3.
The S mainly demonstrates the type of transport in the TE materials and shows an opposite trend (in absolute value) to the σ. Figure 9B shows the obtained S values: a negative value for Bi2Te3 starting from
The power factor (PF) (S2σ) was calculated for both Bi2Te3 and Sb2Te3 and is graphically presented in Figure 9C. The PF for Bi2Te3 at room temperature was estimated as 9 µW·cm-1 K-2, and the maximum value of 12 µW·cm-1 K-2 was reached at 523 K. For Sb2Te3, the room temperature value was 19 µW·cm-1 K-2, and the highest value was 22 µW·cm-1 K-2 around 328 K. The magnitude of PF for Bi2Te3 is slightly lower than the room temperature PF of samples prepared using other solution-chemical syntheses methods of polyol
The κtot values were determined by measuring the thermal diffusivity, mass density, and heat capacity of samples. Figure 9D illustrates the κtot of SPS-consolidated samples. The microstructure analysis of the sintered samples [Figure 4] reveals smaller grains and, consequently, a higher density of grain boundaries in Bi2Te3, resulting in a lower κtot. The overall upward trend in κtot for both the samples is attributed to the bipolar effect in materials with a narrow band gap, and minority charge carriers are easily excited as the temperature increases, contributing to enhanced heat conduction and introducing increased κtot to the samples[64,65]. Across the entire temperature range, it is evident that the κtot for both samples remains consistently below 0.96 W/m·K. This observation underscores the significant impact of nanostructuring, anisotropy, and texturing on the phonon scattering mechanism. In an earlier work on wet-chemically synthesized Bi2-xSbxTe3, room temperature κtot values in the range 1-1.9 W/m·K have been reported for materials with similar composition[60]. Furthermore, studies performed on various nanostructures of Bi2Te3/Sb2Te3 revealed room temperature κtot values of 1.47 and 1.81 W/m·K[66]. Our κtot values are about 10% to 50% lower than these values, which may be associated with the increase in anisotropy due to the large layered microstructure of the samples.
The ZT has been calculated for both samples based on their electrical and thermal transport data, and the results are presented in Figure 9E. At room temperature, the ZT value for the Sb2Te3 sample is 0.65, reaching its highest value of 0.9 at 523 K. The ZT for Bi2Te3 exhibits a linear increase with increasing temperature, starting from about 0.35 at room temperature, reaching its peak value of 0.7 at 573 K. A comparison of ZT values for Bi2Te3 and Sb2Te3 samples in this work with the earlier reports is presented in Figure 10. Bi2Te3 synthesized through thermolysis showed a ZT of 0.62 (at 400 K)[67]. A ZT value of 0.84 (at 423 K) was reported for Bi2Te3 synthesized through the reduction of mechanically milled oxide powders[68], and 0.36 (at 325 K) for the solvothermally synthesized sample[60]. We have earlier reported ZT values of 0.9 (at 373 K) and 1.03 (at 473 K) for single-phase sintered Bi2Te3 synthesized using MW-assisted polyol and hydrothermal techniques[3]. Furthermore, we reported earlier a ZT value of 1.37 (at 523 K) for single-phase sintered Sb2Te3 samples synthesized via the MW-assisted polyol route[49]. An earlier work on Sb2Te3 prepared using MW-assisted thermolysis (~15 min) showed a ZT of 0.96 (at 423 K)[69]. A ZT of 0.55 was reported[70] for hydrothermally synthesized Sb2Te3. Meanwhile, MW-assisted polyol synthesis yielded a ZT of 0.58 (at
Figure 10. Comparison of ZT values of sintered (A) Bi2Te3 and (B) Sb2Te3 samples with earlier reports on binary phases synthesized through different chemical routes. The temperature at which the reported ZT value is reached for the different samples is displayed on the histograms.
CONCLUSIONS
A rapid, energy-efficient, and scalable solution-based synthesis method was developed, using MW-assisted thermolysis process - at 220 °C within 6 min, obtaining successfully bismuth and antimony telluride
DECLARATIONS
Acknowledgments
Hamawandi, B., Pudza, I., and Pudzs, K. thank the Latvian Council of Science for support through project No. lzp-2023/1-0528. Toprak, M. S. acknowledges funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 863222. Ballikaya, S. acknowledges support from the Scientific and Technological Research Council of Turkey (TUBITAK, 119N120). We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for providing experimental facilities. The experiment at the DESY PETRA III synchrotron was performed within proposal No. I-20220381 EC. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. Toprak, M. S. also acknowledges the financial support from Olle Engkvist Foundation (SOEB, 190-0315) for establishing MW synthesis facilities.
Authors’ contributions
Conception and design of the study, methodology, writing - original draft, writing - review & editing, supervision, funding acquisition: Toprak, M. S.
Conception, methodology, writing - original draft, writing - review & editing: Hamawandi, B.
Investigation, data analysis and interpretation, visualization, writing - original draft, writing - review & editing, funding acquisition: Pudza, I.
Investigation: Pudzs, K.
Investigation, methodology, writing - original draft, writing - review & editing, supervision: Kuzmin, A.
Resources: Welter, E.
Investigation, methodology, data analysis and interpretation: Ballikaya, S.
Investigation, methodology: Parsa, P.; Szukiewicz, R.; Kuchowicz, M.
Availability of data and materials
Data will be available from the corresponding author upon reasonable request.
Financial support and sponsorship
This work was supported by the Latvian Council of Science (project No. lzp-2023/1-0528), the European Union's Horizon 2020 research and innovation program under grant agreement No 863222 (UncorrelaTEd), Scientific and Technological Research Council of Turkey (TUBITAK, 119N120), and the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. The funding bodies had no role in the experiment design, collection, analysis and interpretation of data, and writing of the manuscript.
Conflicts of interest
Toprak, M. S. is an Editorial Board Member of the journal Energy Materials. Toprak, M. S. was not involved in any steps of editorial processing, notably including reviewers' selection, manuscript handling and decision making, while the other authors have declared that they have no conflicts of interest.
Ethical approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Copyright
© The Author(s) 2025.
Supplementary Materials
REFERENCES
1. Jaziri, N.; Boughamoura, A.; Müller, J.; Mezghani, B.; Tounsi, F.; Ismail, M. A comprehensive review of Thermoelectric Generators: technologies and common applications. Energy. Rep. 2020, 6, 264-87.
2. Bisht, N.; More, P.; Khanna, P. K.; Abolhassani, R.; Mishra, Y. K.; Madsen, M. Progress of hybrid nanocomposite materials for thermoelectric applications. Mater. Adv. 2021, 2, 1927-56.
3. Hamawandi, B.; Batili, H.; Paul, M.; et al. Minute-made, high-efficiency nanostructured Bi2Te3 via high-throughput green solution chemical synthesis. Nanomaterials 2021, 11, 2053.
4. Yang, J.; Cai, J.; Wang, R.; et al. Entropy engineering realized ultralow thermal conductivity and high seebeck coefficient in lead-free SnTe. ACS. Appl. Energy. Mater. 2021, 4, 12738-44.
5. Zhang, D.; Lim, W. Y. S.; Duran, S. S. F.; Loh, X. J.; Suwardi, A. Additive manufacturing of thermoelectrics: emerging trends and outlook. ACS. Energy. Lett. 2022, 7, 720-35.
6. Channegowda, M.; Mulla, R.; Nagaraj, Y.; et al. Comprehensive insights into synthesis, structural features, and thermoelectric properties of high-performance inorganic chalcogenide nanomaterials for conversion of waste heat to electricity. ACS. Appl. Energy. Mater. 2022, 5, 7913-43.
7. Tippireddy, S.; Kumar D S, P.; Das, S.; Mallik, R. C. Oxychalcogenides as thermoelectric materials: an overview. ACS. Appl. Energy. Mater. 2021, 4, 2022-40.
8. Hamawandi, B.; Ballikaya, S.; Råsander, M.; et al. Composition tuning of nanostructured binary copper selenides through rapid chemical synthesis and their thermoelectric property evaluation. Nanomaterials 2020, 10, 854.
9. Zoui, M. A.; Bentouba, S.; Stocholm, J. G.; Bourouis, M. A review on thermoelectric generators: progress and applications. Energies 2020, 13, 3606.
10. Jaldurgam, F. F.; Ahmad, Z.; Touati, F. Synthesis and performance of large-scale cost-effective environment-friendly nanostructured thermoelectric materials. Nanomaterials 2021, 11, 1091.
11. Gite, A. B.; Palve, B. M.; Gaikwad, V. B.; et al. A facile chemical synthesis of PbTe nanostructures at room temperature. Nanomaterials 2020, 10, 1915.
12. Shi, X. L.; Zou, J.; Chen, Z. G. Advanced thermoelectric design: from materials and structures to devices. Chem. Rev. 2020, 120, 7399-515.
13. Recatala-Gomez, J.; Suwardi, A.; Nandhakumar, I.; Abutaha, A.; Hippalgaonkar, K. Toward accelerated thermoelectric materials and process discovery. ACS. Appl. Energy. Mater. 2020, 3, 2240-57.
14. Murmu, P. P.; Karthik, V.; Liu, Z.; et al. Influence of carrier density and energy barrier scattering on a high seebeck coefficient and power factor in transparent thermoelectric copper iodide. ACS. Appl. Energy. Mater. 2020, 3, 10037-44.
15. Wang, Y.; Bourgès, C.; Rajamathi, R.; Nethravathi, C.; Rajamathi, M.; Mori, T. The effect of reactive electric field-assisted sintering of MoS2/ Bi2Te3 heterostructure on the phase integrity of Bi2Te3 matrix and the thermoelectric properties. Materials 2021, 15, 53.
16. Sato, H. K.; Tamaki, H.; Kanno, T. Large valley degeneracy and high thermoelectric performance in p-type Ba8Cu6Ge40-based clathrates. Appl. Phys. Lett. 2020, 116, 253901.
17. Tarachand; Saxena, M.; Okram, G.; et al. Enhanced thermoelectric performance of solution-grown Bi2Te3 nanorods. Mater. Today. Energy. 2021, 21, 100700.
18. Shi, Z.; Tong, S.; Wei, J.; et al. Regulating multiscale defects to enhance the thermoelectric performance of Ca0.87Ag0.1Dy0.03MnO3 ceramics. ACS. Appl. Mater. Interfaces. 2022, 14, 32166-75.
19. Li, S.; Jiang, J.; Ma, Z.; et al. Rare earth element doping introduces pores to improve thermoelectric properties of p-type
20. Zhuang, H.; Pei, J.; Cai, B.; et al. Thermoelectric performance enhancement in BiSbTe alloy by microstructure modulation via cyclic spark plasma sintering with liquid phase. Adv. Funct. Mater. 2021, 31, 2009681.
21. Li, S.; Huang, Z.; Wang, R.; et al. Precision grain boundary engineering in commercial Bi2Te2.7Se0.3 thermoelectric materials towards high performance. J. Mater. Chem. A. 2021, 9, 11442-9.
22. Jo, S.; Park, S. H.; Shin, H.; et al. Soluble telluride-based molecular precursor for solution-processed high-performance thermoelectrics. ACS. Appl. Energy. Mater. 2019, 2, 4582-9.
23. Irfan, S.; Din, M. A. U.; Manzoor, M. Q.; Chen, D. Effect of co-doping on thermoelectric properties of n-type Bi2Te3 nanostructures fabricated using a low-temperature sol-gel method. Nanomaterials 2021, 11, 2719.
24. Bu, Z.; Zhang, X.; Hu, Y.; et al. A record thermoelectric efficiency in tellurium-free modules for low-grade waste heat recovery. Nat. Commun. 2022, 13, 237.
25. Wiese, J.; Muldawer, L. Lattice constants of Bi2Te3-Bi2Se3 solid solution alloys. J. Phys. Chem. Solids. 1960, 15, 13-6.
26. Zhai, R.; Wu, Y.; Zhu, T.; Zhao, X. Tunable optimum temperature range of high-performance zone melted bismuth-telluride-based solid solutions. Cryst. Growth. Des. 2018, 18, 4646-52.
27. Hamawandi, B.; Mansouri, H.; Ballikaya, S.; et al. A comparative study on the thermoelectric properties of bismuth chalcogenide alloys synthesized through mechanochemical alloying and microwave-assisted solution synthesis routes. Front. Mater. 2020, 7, 569723.
28. Winkler, M.; Liu, X.; König, J. D.; et al. Electrical and structural properties of Bi2Te3 and Sb2Te3 thin films grown by the nanoalloying method with different deposition patterns and compositions. J. Mater. Chem. 2012, 22, 11323.
29. Feng, H.; Wu, C.; Zhang, P.; Mi, J.; Dong, M. Facile hydrothermal synthesis and formation mechanisms of Bi2Te3, Sb2Te3 and Bi2Te3-Sb2Te3 nanowires. RSC. Adv. 2015, 5, 100309-15.
30. Ammar, S.; Fiévet, F. Polyol synthesis: a versatile wet-chemistry route for the design and production of functional inorganic nanoparticles. Nanomaterials 2020, 10, 1217.
31. Batili, H.; Hamawandi, B.; Björn, E. A.; Szukiewicz, R.; Kuchowicz, M.; Toprak, M. S. A comparative study on the surface chemistry and electronic transport properties of Bi2Te3 synthesized through hydrothermal and thermolysis routes. Colloids. Surf. A. Physicochem. Eng. Asp. 2024, 682, 132898.
32. Serrano-Claumarchirant, J. F.; Hamawandi, B.; Ergül, A. B.; et al. Thermoelectric inks and power factor tunability in hybrid films through all solution process. ACS. Appl. Mater. Interfaces. 2022, 14, 19295-303.
33. Ha, H. P.; Oh, Y. J.; Hyun, D. B.; Yoon, E. P. Thermoelectric properties of n-type bismuth telluride based alloys prepared by hot pressing and zone melting method. Int. J. Soc. Mater. Eng. Resour. 2002, 10, 130-4.
34. Batili, H.; Hamawandi, B.; Ergül, A. B.; Toprak, M. S. On the electrophoretic deposition of Bi2Te3 nanoparticles through electrolyte optimization and substrate design. Colloids. Surf. A. Physicochem. Eng. Asp. 2022, 649, 129537.
35. Batili, H.; Hamawandi, B.; Parsa, P.; et al. Electrophoretic assembly and electronic transport properties of rapidly synthesized Sb2Te3 nanoparticles. Appl. Surf. Sci. 2023, 637, 157930.
36. Dong, G.; Zhu, Y.; Chen, L. Microwave-assisted rapid synthesis of Sb2Te3 nanosheets and thermoelectric properties of bulk samples prepared by spark plasma sintering. J. Mater. Chem. 2010, 20, 1976.
37. Welter, E.; Chernikov, R.; Herrmann, M.; Nemausat, R. A beamline for bulk sample X-ray absorption spectroscopy at the high brilliance storage ring PETRA III. AIP. Conf. Proc. 2019, 2054, 040002.
38. Kumar, A.; Misra, D. K.; Bano, S.; Govind, B.; Bhatt, K. A review on sources of uncertainty in thermal conductivity measurement for thermal transport metrology. In: Yadav S, Chaudhary K, Gahlot A, Arya Y, Dahiya A, Garg N, editors. Recent advances in metrology. Singapore: Springer Nature; 2023. pp. 137-45.
39. Kuznetsov, G. V.; Kats, M. D. The errors when determining thermal characteristics by the laser flash method due to the thickness of the sample and the duration of the heating pulse. Meas. Tech. 2012, 55, 454-8.
40. Kalinko, A. xaesa. Available from: https://gitlab.desy.de/aleksandr.kalinko/xaesa [Last accessed on 5 Feb 2025].
41. Kuzmin, A.; Chaboy, J. EXAFS and XANES analysis of oxides at the nanoscale. IUCrJ 2014, 1, 571-89.
42. Timoshenko, J.; Kuzmin, A.; Purans, J. Reverse Monte Carlo modeling of thermal disorder in crystalline materials from EXAFS spectra. Comput. Phys. Commun. 2012, 183, 1237-45.
43. Timoshenko, J.; Kuzmin, A.; Purans, J. EXAFS study of hydrogen intercalation into ReO3 using the evolutionary algorithm. J. Phys. Condens. Matter. 2014, 26, 055401.
44. Mansour, A. N.; Wong-Ng, W.; Huang, Q.; Tang, W.; Thompson, A.; Sharp, J. Structural characterization of Bi2Te3 and Sb2Te3 as a function of temperature using neutron powder diffraction and extended X-ray absorption fine structure techniques. J. Appl. Phys. 2014, 116, 083513.
45. Ankudinov, A. L.; Ravel, B.; Rehr, J. J.; Conradson, S. D. Real-space multiple-scattering calculation and interpretation of X-ray-absorption near-edge structure. Phys. Rev. B. 1998, 58, 7565-76.
46. Rehr, J. J.; Albers, R. C. Theoretical approaches to X-ray absorption fine structure. Rev. Mod. Phys. 2000, 72, 621-54.
47. Hedin, L.; Lundqvist, B. I. Explicit local exchange-correlation potentials. J. Phys. C. Solid. State. Phys. 1971, 4, 2064-83.
48. Timoshenko, J.; Kuzmin, A. Wavelet data analysis of EXAFS spectra. Comput. Phys. Commun. 2009, 180, 920-5.
49. Hamawandi, B.; Ballikaya, S.; Batili, H.; et al. Facile solution synthesis, processing and characterization of n- and p-type binary and ternary Bi-Sb tellurides. Appl. Sci. 2020, 10, 1178.
50. Jonane, I.; Anspoks, A.; Kuzmin, A. Advanced approach to the local structure reconstruction and theory validation on the example of the W L3-edge extended X-ray absorption fine structure of tungsten. Model. Simul. Mater. Sci. Eng. 2018, 26, 025004.
51. Jonane, I.; Anspoks, A.; Aquilanti, G.; Kuzmin, A. High-temperature X-ray absorption spectroscopy study of thermochromic copper molybdate. Acta. Mater. 2019, 179, 26-35.
52. Shannon, R. D. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta. Cryst. A. 1976, 32, 751-67.
53. Eivari, H.; Sohbatzadeh, Z.; Mele, P.; Assadi, M. Low thermal conductivity: fundamentals and theoretical aspects in thermoelectric applications. Mater. Today. Energy. 2021, 21, 100744.
54. Parashchuk, T.; Knura, R.; Cherniushok, O.; Wojciechowski, K. T. Ultralow lattice thermal conductivity and improved thermoelectric performance in Cl-doped Bi2Te3-xSex alloys. ACS. Appl. Mater. Interfaces. 2022, 14, 33567-79.
55. Zahid, A. H.; Han, Q. A review on the preparation, microstructure, and photocatalytic performance of Bi2O3 in polymorphs. Nanoscale 2021, 13, 17687-724.
56. Sun, G.; Li, B.; Wang, S.; et al. Selective growth of wide band gap atomically thin Sb2O3 inorganic molecular crystal on WS2. Nano. Res. 2019, 12, 2781-7.
57. Guo, S.; Zhu, Z.; Hu, X.; et al. Ultrathin tellurium dioxide: emerging direct bandgap semiconductor with high-mobility transport anisotropy. Nanoscale 2018, 10, 8397-403.
58. Zhao, Y.; Dyck, J. S.; Hernandez, B. M.; Burda, C. Enhancing thermoelectric performance of ternary nanocrystals through adjusting carrier concentration. J. Am. Chem. Soc. 2010, 132, 4982-3.
59. Scheele, M.; Oeschler, N.; Veremchuk, I.; et al. ZT enhancement in solution-grown Sb2-xBixTe3 nanoplatelets. ACS. Nano. 2010, 4, 4283-91.
60. Zhang, C.; Peng, Z.; Li, Z.; Yu, L.; Khor, K. A.; Xiong, Q. Controlled growth of bismuth antimony telluride BixSb2-xTe3 nanoplatelets and their bulk thermoelectric nanocomposites. Nano. Energy. 2015, 15, 688-96.
61. Nam, G.; Ha, J. U.; Chung, D. S. Thermoelectric power factor exceeding 50 μW m-1K-2 from water-borne colloids of polymer semiconductors. J. Mater. Chem. C. 2020, 8, 13439-44.
62. Yang, H. Q.; Miao, L.; Zhang, M.; et al. Low-temperature, solution-based, scalable synthesis of Sb2Te3 nanoparticles with an enhanced power factor. J. Electron. Mater. 2014, 43, 2165-73.
63. Ruamruk, S.; Chayasombat, B.; Singsoog, K.; et al. Power factor of Bi2Te3 and Sb2Te3 enhanced by high density and hardness. Suranaree. J. Sci. Technol. 2023, 30, 030145(1-5).
64. Imamuddin, M.; Dupre, A. Thermoelectric properties of p-type Bi2Te3-Sb2Te3-Sb2Se3 alloys and N-type Bi2Te3-Bi2Se3 alloys in the temperature range 300 to 600 K. Phys. Stat. Sol. 1972, 10, 415-24.
65. Han, M. K.; Jin, Y.; Lee, D. H.; Kim, S. J. Thermoelectric properties of Bi2Te3: CuI and the effect of its doping with Pb atoms. Materials 2017, 10, 1235.
66. Park, D.; Park, S.; Jeong, K.; Jeong, H. S.; Song, J. Y.; Cho, M. H. Thermal and electrical conduction of single-crystal Bi2Te3 nanostructures grown using a one step process. Sci. Rep. 2016, 6, 19132.
67. Son, J. S.; Choi, M. K.; Han, M. K.; et al. n-type nanostructured thermoelectric materials prepared from chemically synthesized ultrathin Bi2Te3 nanoplates. Nano. Lett. 2012, 12, 640-7.
68. Lim, Y. S.; Wi, S.; Lee, G. Synthesis of n-type Bi2Te1-xSex compounds through oxide reduction process and related thermoelectric properties. J. Eur. Ceram. Soc. 2017, 37, 3361-6.
69. Mehta, R. J.; Zhang, Y.; Karthik, C.; et al. A new class of doped nanobulk high-figure-of-merit thermoelectrics by scalable bottom-up assembly. Nat. Mater. 2012, 11, 233-40.
70. Dharmaiah, P.; Hong, S. Hydrothermal method for the synthesis of Sb2Te3, and Bi0.5Sb1.5Te3 nanoplates and their thermoelectric properties. Int. J. Appl. Ceram. Technol. 2018, 15, 132-9.
Cite This Article
Open Access
, ... Muhammet S. ToprakHow to Cite
Hamawandi, B.; Parsa, P.; Pudza, I.; Pudzs, K.; Kuzmin, A.; Ballikaya, S.; Welter, E.; Szukiewicz, R.; Kuchowicz, M.; Toprak, M. S. Scalable solution chemical synthesis and comprehensive analysis of Bi2Te3 and Sb2Te3. Energy Mater. 2025, 5, 500065. http://dx.doi.org/10.20517/energymater.2024.204
Download Citation
Export Citation File:
Type of Import
Tips on Downloading Citation
Citation Manager File Format
Type of Import
Direct Import: When the Direct Import option is selected (the default state), a dialogue box will give you the option to Save or Open the downloaded citation data. Choosing Open will either launch your citation manager or give you a choice of applications with which to use the metadata. The Save option saves the file locally for later use.
Indirect Import: When the Indirect Import option is selected, the metadata is displayed and may be copied and pasted as needed.
About This Article
Special Issue
Copyright
Data & Comments
Data
0
Comments
Comments must be written in English. Spam, offensive content, impersonation, and private information will not be permitted. If any comment is reported and identified as inappropriate content by OAE staff, the comment will be removed without notice. If you have any queries or need any help, please contact us at [email protected].