Enhanced Thermoelectric Performance of Lightly Pb-Doped Sb<sub>2</sub>Te<sub>3</sub> Polycrystalline Alloys for Power Generation in Midtemperature Range

Park, Okmin; Lee, Kyu Hyoung; Park, Sang Jeong; Lee, Se Woong; Kim, Sang-il

doi:https://doi.org/10.1155/2023/9077811

International Journal of Energy Research

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Abstract Introduction Results and Discussion Conclusion Data Availability Conflicts of Interest Authors’ Contributions Acknowledgments Supplementary Materials References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 9077811 | https://doi.org/10.1155/2023/9077811

Enhanced Thermoelectric Performance of Lightly Pb-Doped Sb₂Te₃ Polycrystalline Alloys for Power Generation in Midtemperature Range

Okmin Park,¹Kyu Hyoung Lee,²Sang Jeong Park,¹Se Woong Lee,¹and Sang-il Kim¹

Academic Editor: Nagaraj Nandihalli

Received07 Jul 2023

Revised22 Aug 2023

Accepted19 Sept 2023

Published10 Oct 2023

Abstract

Sb₂Te₃ alloys are promising thermoelectric materials because of their outstanding electrical transport properties in the midtemperature range of 500–700 K, while codoping with multiple elements has been successful to improve their thermoelectric performance. In this study, enhanced thermoelectric properties with a maximum thermoelectric figure of merit of 0.97 are reported for singly and lightly Pb-doped Sb₂Te₃ polycrystalline alloys (Sb_2–PbTe₃). Very light Pb doping in the range in the Sb_2–PbTe₃ alloys yielded significantly improved carrier transport properties and increased electrical conductivity while the Seebeck coefficient is decreased moderately, since the density-of-state effective mass is improved much. As a result, power factor for the Pb-doped Sb₂Te₃ is largely increased up to 3.7 mW/mK² at 300 K. The lattice thermal conductivity decreased considerably owing to the additional point defect phonon scattering by the Pb despite slight doping. Consequently, a maximum thermoelectric figure of merit of 0.97 was obtained for Sb_1.9875Pb_0.0125Te₃ () at 600 K, which is the highest reported value for singly doped Sb₂Te₃-based alloys. A maximum energy conversion efficiency was calculated to be 9.0% for a temperature difference of 350 K, which is higher than that for other singly or codoped Sb₂Te₃ alloys.

1. Introduction

Thermoelectric materials have been attracting attention for solid-state cooling and energy harvesting because they can convert heat directly into electricity. Therefore, there exist many potential applications, including cryoprobes, on-chip cooling, and power generators based on waste heat from automobiles and industries [1–4]. However, the widespread applications of thermoelectric materials depend on their conversion efficiency, which is typically characterized by the thermoelectric figure of merit. The thermoelectric figure of merit is a dimensionless quantity given by , where , , , and are the Seebeck coefficient, electrical conductivity, absolute temperature, and total thermal conductivity, respectively. Note that the average figure of merit () is an important measure of the power generation efficiency of a thermoelectric material over a temperature range. The maximum energy conversion efficiency () of a thermoelectric material can be estimated using the following equation: where is the temperature of the cold side of the thermoelectric material, is the temperature of the hot side of the thermoelectric material, is , and is .

(Bi,Sb)₂Te₃ solid solution alloys are the most widely used -type thermoelectric materials at room temperature. In particular, Sb-rich alloys such as Bi_0.5Sb_1.5Te₃ and Bi_0.4Sb_1.6Te₃ are known to exhibit high -type thermoelectric performance because of their optimized carrier transport properties [5–7]. Pristine Bi₂Te₃ typically exhibits -type electrical transport behavior; interestingly, when Bi₂Te₃ is alloyed with Sb₂Te₃, which exhibits -type electrical transport properties, a high of >2,000 S/cm can be obtained [8, 9]. Consequently, (Bi,Sb)₂Te₃ alloys can exhibit a high thermoelectric performance in the low-temperature range of 300–400 K. However, their performance degrades rapidly at higher temperatures owing to the occurrence of bipolar conduction, which is unfavorable for electric power generation [10]. In contrast, Sb₂Te₃ alloys demonstrate a high thermoelectric performance in the midtemperature range of 500–700 K, with no significant occurrence of bipolar conduction. Nevertheless, the maximum of Sb₂Te₃ alloys is lower than that of (Bi,Sb)₂Te₃ alloys.

Several studies have been conducted to enhance the of Sb₂Te₃ alloys in the midtemperature range. In particular, codoping Sb₂Te₃ with multiple elements has been shown to be successful [11–14]. For instance, Qin et al. reported a of 1.0 at 673 K for Sb₂Te₃ codoped with Mn and In [12]; in addition, Hu et al. reported a maximum of 0.92 at 710 K for Sb₂Te₃ codoped with In and Ag [13]. Moreover, a of 0.96 at 680 K was reported for Sb₂Te₃ codoped with Mg and In [14]. However, Sb₂Te₃ has been typically shown to exhibit a high thermoelectric performance when codoped with two or more elements [15–18]. The maximum achievable value for singly doped Sb₂Te₃ alloys is 0.7, which is significantly lower than that obtained via codoping [13, 19].

In this study, Sb₂Te₃ was doped with a single dopant, Pb, to enhance its thermoelectric performance. The performance of (Bi,Sb)₂Te₃ alloys has been shown to improve when Pb was used as an acceptor dopant [20–22]. To this end, a series of Sb_2–PbTe₃ alloys with , 0.0025, 0.005, 0.0075, 0.01, and 0.0125 was synthesized, where is the doping content. Pb doping significantly enhanced the power factor of the alloys, and a maximum of 0.97 at 600 K was achieved for (i.e., Sb_1.9875Pb_0.0125Te₃). The thermoelectric properties of the Sb_2–PbTe₃ alloys were analyzed using various phenomenological parameters, including the density of state (DOS) effective mass () and weighted mobility (). was found to increase linearly with the doping content, which in turn positively affected the thermoelectric performance of the Sb_2–PbTe₃ alloys. In addition, the further doping of Pb in Sb_2–PbTe₃ was investigated by introducing large amounts of Pb corresponding to , 0.1, 0.15, and 0.2 (Supplementary Information (available here)).

2. Experimental Methods

Polycrystalline Sb_2–PbTe₃ (, 0.0025, 0.005, 0.0075, 0.01, and 0.0125) samples were prepared using the traditional solid-state reaction method. Stoichiometric quantities of high purity Sb (99.999%; 5N Plus), Pb (99.999%; Alfa Aesar), and Te (99.999%; 5N Plus) were weighed according to the nominal composition of the desired alloy, placed in a quartz tube, and sealed under vacuum (10^–5 Torr). The sealed quartz ampoules were heated at 1,000 K for 4 h, and this temperature was further maintained for 6 h. Next, the ampoules were quenched in water at room temperature, following which the respective metal ingots were extracted from the ampoules. Ball milling (SPEX 8000D, Costa Mesa, USA) was performed in an Ar atmosphere to convert the ingots into powders. Subsequently, the powders were sintered at 573 K for 5 min at a pressure of 70 MPa under vacuum (10^–6 Torr) to form cylindrical bulk pellets using spark plasma sintering (SPS; SPS-1030, Sumitomo Coal Mining Co. Ltd., Tokyo, Japan). Note that the sintered bulk samples had a relative density of more than 99%.

The crystal structure of the samples was analyzed using X-ray diffraction (XRD; D8 Discover, Bruker, USA) with Cu–K_α1 radiation. Atomic percentage of Pb dopant in the samples is measured using energy-dispersive spectroscopy (EDS, Quantax Xflash 6-60, Bruker, USA) by scanning electron microscope (SEM, SU8010, HITACHI, Japan). The and values of the samples were measured using a thermoelectric property measuring system (ZEM-3M8, Advance Riko, Japan) in a He atmosphere between 300 and 650 K. The Hall measurements were conducted in the van der Pauw configuration at 300 K using a Hall measurement system (HMS-5300, Ecopia, Korea). A laser flash analyzer (LFA457, Netzsch, Germany) was used to obtain the thermal diffusivity () of the samples, which was used to calculate , where and are the density and specific heat capacity of the sample, respectively. was measured (relative density of ≥97%), while J/g·K was used based on previously reported data [23]. The results corresponding to high Pb doping (i.e., ) are presented in the Supplementary Information.

3. Results and Discussion

Figures 1(a) and 1(b) show the XRD patterns of the polycrystalline bulk Sb_2-PbTe₃ (, 0.0025, 0.005, 0.0075, 0.01, and 0.0125) samples obtained along the directions parallel (PA) and perpendicular (PE) to the sintering direction, respectively. The XRD patterns confirm the synthesis of different Pb-doped Sb₂Te₃ phases in accordance with the JCPDS#01-071-0393 card. The lattice parameters ( and ) of the samples were calculated using the (015) and (1010) diffraction peaks. Figure 1(c) shows the lattice parameters as functions of . The error bars indicate the measurement error of the diffraction data of Figures 1(a) and 1(b). The lattice parameter did not vary significantly with , whereas the lattice parameter increased monotonically with . This increase in with can be explained by the difference between the ionic radii of Sb³⁺ (90 pm) and Pb²⁺ (133 pm), which enables the successful doping of Pb at the Sb sites. In addition, Table 1 shows atomic ratio in Sb_2-PbTe₃ measured by EDS, and it was confirmed systematic increase in the amount of Pb (see Supplementary Information Figure S1 for EDS mapping). However, PbTe appeared as an impurity in the highly doped samples (i.e., ; see Supplementary Information Figure S2(a)). This was further confirmed by the behavior of the corresponding lattice parameters with (see Supplementary Information Figure S2(b)).

(a)

(b)

(c)

Figures 2(a) and 2(e) show as a function of temperature for the Pb-doped Sb₂Te₃ samples along the PE and PA directions, respectively. of the Sb_2–PbTe₃ samples increased with along both the PE and PA directions. The values at 300 K along the PE direction were 2,240, 2,440, 2,620, 3,080, 3,570, and 3,770 S/cm for , 0.0025, 0.005, 0.0075, 0.01, and 0.0125, respectively, whereas the values at 300 K along the PA direction were 1,640, 1,870, 2,020, 2,370, 2,430, and 2,730 S/cm for , 0.0025, 0.005, 0.0075, 0.01, and 0.0125, respectively. For the highly doped samples (), there was a sharp increase in , which had values in the range 5000–6000 S/cm; however, decreased with a further increase in owing to the formation of secondary PbTe phases in these samples (see Supplementary Information; Figure S3(a)). This decrease in with an increase in the doping content is because of the relatively low of the PbTe phase of approximately 120–200 S/cm [24, 25].

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Figures 2(b) and 2(f) show as a function of temperature for the Sb_2–PbTe₃ samples along the PE and PA directions, respectively. increased with temperature for all the samples. The value for was slightly higher than that for ; however, for , decreased with along both the measured directions. Compared to the relatively large increase in with (Figures 2(a) and 2(e)), the decrease in with was less significant. However, with further Pb doping (i.e., ), decreased significantly, reaching a minimum value of 30 μV/K (see Supplementary Information Figure S3(b)). Figures 2(c) and 2(g) show the calculated power factor of the Sb_2–PbTe₃ samples as a function of temperature along the PE and PA directions, respectively. The power factor of the Pb-doped samples was significantly higher than that of pristine Sb₂Te₃ across the entire temperature range. A maximum power factor of 3.66 mW/mK² was obtained for at 300 K along the PE direction, which is 39% higher than that for . A maximum power factor of 2.75 mW/mK² was obtained for along the PA direction, which is 40% higher than that for (1.96 mW/mK²). A gradual decrease in the power factor was observed with further doping (see Supplementary Information Figure S3(c)).

Figures 2(d) and 2(h) show as a function of temperature for the Sb_2–PbTe₃ samples along the PE and PA directions, respectively. is related to the maximum theoretical efficiency of a thermoelectric material and can be defined using the following analytical approximation of the Drude-Sommerfeld free-electron model for [26]: where and denote Planck’s constant and the electron mass, respectively. Note that is proportional to the maximum power factor of the sample, which can be obtained by optimizing the Hall carrier concentration . In general, increased with the doping content along both the PE and PA directions. This confirms that the Pb-doped samples have enhanced electrical transport properties and hence can exhibit enhanced thermoelectric performance.

Figures 3(a) and 3(b) show and (along both the PE and PA directions) of the Sb_2–PbTe₃ samples as functions at 300 K. steadily increased with increasing Pb content and reached a maximum value of for . By contrast, decreased linearly with along both the measured directions. Moreover, along the PA direction was approximately 27% lower than that along the PE direction. The values along the PE direction were 281, 258, 254, 239, and 218 cm²/Vs for , 0.0025, 0.005, 0.0075, 0.01, and 0.0125, respectively, whereas the values along the PA direction were 221, 216, 214, 202, and 172 cm²/Vs for , 0.0025, 0.005, 0.0075, 0.01, and 0.0125, respectively. The increase in with can be attributed to the increase in with , which in turn is owing to the substitution of the Sb³⁺ ions by the Pb²⁺ ions. Supplementary Information Figure S4 presents the corresponding results of the highly doped samples.

(a)

(b)

(c)

(d)

The electrical transport properties of semiconductors are determined by the DOS at the Fermi level. The magnitude of the DOS is directly related to . Thus, can be defined in terms of changes in the electron structure using the single parabolic band model [27], such that

Figures 3(c) and 3(d) show of the Sb_2–PbTe₃ samples as a function of along the PE and PA directions, respectively. The insets in Figures 3(c) and 3(d) show as a function of for different samples, where the curves correspond to fixed values. increased with the Pb content along both the PE and PA directions, similar to . The reason for this increase in with is that the rate of increase of with is faster than the rate of decrease of with . The values at 300 K along the PE direction were 0.960, 1.05, 1.09, 1.16, 1.17, and 1.26 ( being the rest mass of an electron) for , 0.0025, 0.005, 0.0075, 0.01, and 0.0125, respectively. along the PA direction also exhibited a similar trend. The maximum value of along the PA direction was 1.34 for . However, for , the value at 300 K decreased linearly with increasing doping content (Supplementary Information Figures S4(c) and (d)). For , of the highly doped samples was lower than that of pristine Sb₂Te₃.

Figure 4 shows and the lattice thermal conductivity of the Sb_2–PbTe₃ samples as functions of temperature along the PE and PA directions. of the Pb-doped samples varied nonmonotonically with along both the measured directions, as shown in Figures 4(a) and 4(c). The insets in Figures 4(a) and 4(c) show the electrical thermal conductivity of the Sb_2–PbTe₃ samples as a function of temperature, which was calculated using the Wiedemann-Franz law [28], namely, (where is the Lorenz number). can be calculated using the following equation [29]:

(a)

(b)

(c)

(d)

Figures 4(b) and 4(d) show as a function of temperature along the PE and PA directions, respectively, which was calculated by subtracting from . decreased with owing to an increase in the point defect phonon scattering by the Pb²⁺ ions. The for high-doped samples for and 0.0012 for the PE direction was calculated very low, but this seems to be due the error in the calculation, which can be expected from the error in for very high conductive alloys ( S/cm) [25]. (See Figure S5 in Supplementary Materials for thermal transport properties of the highly doped Sb_2–PbTe₃ samples along the PE direction.)

Figures 5(a) and 5(b) show the of the Sb_2–PbTe₃ samples as a function of temperature along the PE and PA directions, respectively. A maximum or of 0.97 was obtained for at 600 K along the PE direction, which is approximately 45% higher than that of pristine Sb₂Te₃ ( at 550 K). A of 0.84 was obtained for at 550 K along the PA direction, which is 33% higher than that of pristine Sb₂Te₃ ( at 550 K). (See Figure S6 in Supplementary Materials for of the highly doped Sb_2–PbTe₃ samples.)

(a)

(b)

(c)

(d)

(e)

(f)

Figure 5(c) compares the values of Sb_1.9875Pb_0.0125Te₃ (i.e., ) and several high-performance thermoelectric alloys in the midtemperature (namely, CeFe₄Sb₁₂, Yb_0.3Co₄Sb₁₂, and Sn_0.098Cu_0.02Se) and near-room temperature (namely, -type Bi_0.5Sb_1.5Te₃ and Bi_0.4Sb_1.6Te₃) range [30–34]. The values of Sb_1.9875Pb_0.0125Te₃ in this temperature range were comparable to those of filled skutterudites such as XFe₃Sb₁₂ and XCo₃Sb₁₂ (where , Ce, In, etc.), which require a complex and lengthy synthesis process [32–34]. In addition, the values of Sb_1.9875Pb_0.0125Te₃ were comparable to those of Sb₂Te₃ alloys codoped with In (Figure 5(d)). Furthermore, the values of Sb_1.9875Pb_0.0125Te₃ were much higher than those of codoped Sb₂Te₃ alloys in the temperature range 300–600 K. Consequently, the of Sb_1.9875Pb_0.0125Te₃ was 0.71, which is higher than that of the codoped Sb₂Te₃ alloys (Figure 5(e)).

Figure 5(f) compares the values of Sb_1.9875Pb_0.0125Te₃ and other alloys. A of 9.0% was obtained for Sb_1.9875Pb_0.0125Te₃ corresponding to a temperature difference of 350 K, which was calculated using Eq. (1). This is 32% higher than that of singly doped Sb_1.85In_0.15Te₃ () [13]. Moreover, although Mn_0.02Sb_1.83In_0.15Te₃ () exhibited the highest [12], of Sb_1.9875Pb_0.0125Te₃ exceeded that of Mn_0.02Sb_1.83In_0.15Te₃. The singly and lightly Pb-doped Sb₂Te₃ could outperform other singly or codoped Sb₂Te₃ with respect to power generation in midtemperature range.

4. Conclusion

In this study, we synthesized a series of polycrystalline bulk Sb_2–PbTe₃ (with , 0.0025, 0.005, 0.0075, 0.01, and 0.0125) samples using the traditional solid-state reaction method. The electrical conductivity of the samples increased from 2,240 S/cm for pristine Sb₂Te₃ to 3,570 S/cm with Pb doping. However, the Seebeck coefficient of the samples was not affected significantly by the improved effective mass. An optimal power factor of 3.7 mW/mK² was obtained at 300 K for , which is 39% higher than that of the pristine sample (2.6 mW/mK²). The lattice thermal conductivity of the Pb-doped samples decreased significantly with the doping content owing to an increase in point defect phonon scattering. Consequently, a maximum value of 0.97 was obtained for , which is 45% higher than that of pristine Sb₂Te₃. We also compared the performance of the Sb_2–PbTe₃ alloys developed in this work with that of other high-efficiency thermoelectric alloys in the midtemperature range, including filled skutterudites and codoped Sb₂Te₃ alloys.

Data Availability

Data are available upon reasonable request.

Conflicts of Interest

The authors declare that they have no competing interests.

Authors’ Contributions

Okmin Park and Kyu Hyoung Lee contributed equally to this work.

Acknowledgments

This study was supported by the Nano·Material Technology Development Program under the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2022M3H4A1A04076667).

Supplementary Materials

The energy-dispersive spectroscopy (Quantax Xflash 6-60, Bruker, USA) by scanning electron microscope (SU8010, HITACHI, Japan) is measured to confirm the doping for the samples. Table S1: atomic percentage in Sb_2-PbTe₃ samples obtained from energy-dispersive spectroscopy (EDS). Figure S1: EDS mapping images of Sb_2-PbTe₃ samples (, 0.0025, 0.005, 0.075, 0.01, and 0.0125). The higher doping of Pb in Sb_2–PbTe₃ beyond was investigated by introducing large amounts of Pb corresponding to , 0.1, 0.15, and 0.2, and the results are shown in Supplementary Materials. Figure S2: (a) XRD patterns and (b) lattice parameters of the highly doped Sb_2–PbTe₃ samples. Figure S3: thermoelectric transport properties of the highly doped Sb_2–PbTe₃ samples along the PE direction: (a) electrical conductivity, (b) Seebeck coefficient, and (c) power factor as functions of temperature. Figure S4: carrier transport properties of the highly doped Sb_2–PbTe₃ samples along the PE direction: (a) Hall carrier concentration, (b) Hall mobility, and (c) DOS effective mass, as functions of the doping content. (d) Logarithmic carrier concentration as a function of the absolute Seebeck coefficient. Figure S5: thermal transport properties of the highly doped Sb_2–PbTe₃ samples along the PE direction. (a) Total and (b) lattice thermal conductivity, as functions of temperature. The inset in (a) shows the electron thermal conductivity as a function of temperature. Figure S6: (a) thermoelectric figure of merit and (b) weighted mobility of the highly doped Sb_2–PbTe₃ samples, as functions of temperature. (Supplementary Materials)

References

Z. H. Zheng, X. L. Shi, D. W. Ao et al., “Harvesting waste heat with flexible Bi2Te3 thermoelectric thin film,” Nature Sustainability, vol. 6, no. 2, pp. 180–191, 2023.
View at: Publisher Site | Google Scholar
B. Hu, X. L. Shi, J. Zou, and Z. G. Chen, “Thermoelectrics for medical applications: progress, challenges, and perspectives,” Chemical Engineering Journal, vol. 437, article 135268, 2022.
View at: Publisher Site | Google Scholar
X. L. Shi, W. D. Liu, M. Li et al., “A solvothermal synthetic environmental design for high-performance SnSe-based thermoelectric materials,” Advanced Energy Materials, vol. 12, no. 20, article 2200670, 2022.
View at: Publisher Site | Google Scholar
Z. Miao, X. Meng, and L. Liu, “Improving the ability of thermoelectric generators to absorb industrial waste heat through three-dimensional structure optimization,” Applied Thermal Engineering, vol. 228, article 120480, 2023.
View at: Publisher Site | Google Scholar
Y. Yu, D. S. He, S. Zhang et al., “Simultaneous optimization of electrical and thermal transport properties of Bi_0.5Sb_1.5Te₃ thermoelectric alloy by twin boundary engineering,” Nano Energy, vol. 37, pp. 203–213, 2017.
View at: Publisher Site | Google Scholar
S. I. Kim, K. H. Lee, H. A. Mun et al., “Dense dislocation arrays embedded in grain boundaries for high-performance bulk thermoelectrics,” Science, vol. 348, no. 6230, pp. 109–114, 2015.
View at: Publisher Site | Google Scholar
B. Poudel, Q. Hao, Y. Ma et al., “High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys,” Science, vol. 320, no. 5876, pp. 634–638, 2008.
View at: Publisher Site | Google Scholar
W. Zheng, Y. Luo, Y. Liu, J. Shi, R. Xiong, and Z. Wang, “Synergistical tuning interface barrier and phonon propagation in Au–Sb₂Te₃ nanoplate for boosting thermoelectric performance,” Journal of Physical Chemistry Letters, vol. 10, no. 17, pp. 4903–4909, 2019.
View at: Publisher Site | Google Scholar
J. Wang, C. Zhou, Y. Yu et al., “Enhancing thermoelectric performance of Sb₂Te₃ through swapped bilayer defects,” Nano Energy, vol. 79, article 105484, 2021.
View at: Publisher Site | Google Scholar
P. K. Nguyen, K. H. Lee, J. Moon et al., “Spark erosion: a high production rate method for producing Bi0.5Sb1.5Te3nanoparticles with enhanced thermoelectric performance,” Nanotechnology, vol. 23, no. 41, article 415604, 2012.
View at: Publisher Site | Google Scholar
H. Qin, J. Zhu, N. Li et al., “Enhanced mechanical and thermoelectric properties enabled by hierarchical structure in medium-temperature Sb₂Te₃ based alloys,” Nano Energy, vol. 78, article 105228, 2020.
View at: Publisher Site | Google Scholar
H. Qin, J. Zhu, B. Cui et al., “Achieving a high average zT value in Sb₂Te₃-based segmented thermoelectric materials,” ACS Applied Materials & Interfaces, vol. 12, no. 1, pp. 945–952, 2020.
View at: Publisher Site | Google Scholar
L. P. Hu, T. J. Zhu, X. Q. Yue et al., “Enhanced figure of merit in antimony telluride thermoelectric materials by In-Ag co-alloying for mid-temperature power generation,” Acta Materialia, vol. 85, pp. 270–278, 2015.
View at: Publisher Site | Google Scholar
L. Xie, H. Qin, J. Zhu et al., “Realizing excellent thermoelectric performance of Sb₂Te₃ based segmented leg with a wide temperature range using one-step sintering,” Advanced Electronic Materials, vol. 6, no. 2, article 1901178, 2020.
View at: Publisher Site | Google Scholar
R. J. Mehta, Y. Zhang, H. Zhu et al., “Seebeck and figure of merit enhancement in nanostructured antimony telluride by antisite defect suppression through sulfur doping,” Nano Letters, vol. 12, no. 9, pp. 4523–4529, 2012.
View at: Publisher Site | Google Scholar
M. Wei, X.-L. Shi, Z.-H. Zheng et al., “Directional thermal diffusion realizing inorganic Sb₂Te₃/Te hybrid thin films with high thermoelectric performance and flexibility,” Advanced Functional Materials, vol. 32, no. 45, article 2207903, 2022.
View at: Publisher Site | Google Scholar
J.-E. Hong, S.-K. Lee, and S.-G. Yoon, “Enhanced thermoelectric properties of thermal treated Sb₂Te₃ thin films,” Journal of Alloys and Compounds, vol. 583, pp. 111–115, 2014.
View at: Publisher Site | Google Scholar
M. Wei, T.-B. Chen, J.-G. Hu et al., “Effect of organic nano-components on the thermoelectric properties of Sb₂Te₃ nanocrystal thin film,” Scripta Materialia, vol. 185, pp. 105–110, 2020.
View at: Publisher Site | Google Scholar
G. Thankamma and A. G. Kunjomana, “Enhancement of thermoelectric efficiency in vapor deposited _Sb2Te3and Sb1.8In0.2Te3crystals,” Crystal Research and Technology, vol. 49, no. 4, pp. 212–219, 2014.
View at: Publisher Site | Google Scholar
H.-S. Kim, K. H. Lee, J. Yoo et al., “Effect of substitutional Pb doping on bipolar and lattice thermal conductivity in p-type Bi_0.48Sb_1.52Te₃,” Materials, vol. 10, no. 7, p. 763, 2017.
View at: Publisher Site | Google Scholar
M.-K. Han, X. Zhou, C. Uher, S.-J. Kim, and M. G. Kanatzidis, “Increase in the figure of merit by Cd-substitution in Sn_1–xPb_xTe and effect of Pb/Sn ratio on thermoelectric properties,” Advanced Energy Materials, vol. 2, no. 10, pp. 1218–1225, 2012.
View at: Publisher Site | Google Scholar
N. K. Singh, S. Bathula, B. Gahtori, K. Tyagi, D. Haranath, and A. Dhar, “The effect of doping on thermoelectric performance of p-type SnSe: promising thermoelectric material,” Journal of Alloys and Compounds, vol. 668, pp. 152–158, 2016.
View at: Publisher Site | Google Scholar
A. S. Pashinkin, A. S. Malkova, and M. S. Mikhailova, “The heat capacity of solid antimony telluride Sb₂Te₃,” Russian Journal of Physical Chemistry, vol. 82, no. 5, pp. 878-879, 2008.
View at: Publisher Site | Google Scholar
K. Ahmad, Z. Almutairi, and C. Wan, “Thermoelectric properties of PbTe-based graphene nanocomposite,” Journal of Materials Science: Materials in Electronics, vol. 31, no. 23, pp. 20996–21004, 2020.
View at: Publisher Site | Google Scholar
K. Zhang, H. Wang, W. Su et al., “Trace bismuth and iodine co-doping enhanced thermoelectric performance of PbTe alloys,” Journal of Physics D: Applied Physics, vol. 53, no. 24, p. 245501, 2020.
View at: Publisher Site | Google Scholar
G. J. Snyder, A. H. Snyder, M. Wood, R. Gurunathan, B. H. Snyder, and C. Niu, “Weighted mobility,” Advanced Materials, vol. 32, no. 25, p. 2001537, 2020.
View at: Publisher Site | Google Scholar
K. H. Lee, S.-I. Kim, J.-C. Lim, J. Y. Cho, H. Yang, and H.-S. Kim, “Approach to determine the density-of-states effective mass with carrier concentration-dependent Seebeck coefficient,” Advanced Functional Materials, vol. 32, no. 33, article 2203852, 2022.
View at: Publisher Site | Google Scholar
L. Lorenz, “Bestimmung der Wärmegrade in absolutem Maasse,” Annalen der Physik und Chemie, vol. 223, no. 11, pp. 429–452, 1872.
View at: Publisher Site | Google Scholar
H.-S. Kim, Z. M. Gibbs, Y. Tang, H. Wang, and G. J. Snyder, “Characterization of Lorenz number with Seebeck coefficient measurement,” APL Materials, vol. 3, no. 4, article 041506, 2015.
View at: Publisher Site | Google Scholar
H. Li, X. Su, X. Tang et al., “Grain boundary engineering with nano-scale InSb producing high performance In_xCe_yCo₄Sb_12+z skutterudite thermoelectrics,” Journal of Materiomics, vol. 3, no. 4, pp. 273–279, 2017.
View at: Publisher Site | Google Scholar
G. Tan, W. Liu, S. Wang et al., “Rapid preparation of CeFe₄Sb₁₂ skutterudite by melt spinning: rich nanostructures and high thermoelectric performance,” Journal of Materials Chemistry A, vol. 1, no. 40, pp. 12657–12668, 2013.
View at: Publisher Site | Google Scholar
D. Qin, B. Cui, X. Meng et al., “High thermoelectric performance from high carrier mobility and reduced lattice thermal conductivity in Ba, Yb double-filled skutterudites,” Materials Today Physics, vol. 8, pp. 128–137, 2019.
View at: Publisher Site | Google Scholar
K.-H. Lee, H.-S. Kim, S.-I. Kim et al., “Enhancement of thermoelectric figure of merit for Bi_0.5Sb_1.5Te₃ by metal nanoparticle decoration,” Journal of Electronic Materials, vol. 41, no. 6, pp. 1165–1169, 2012.
View at: Publisher Site | Google Scholar
K.-H. Lee, S. Hwang, B. Ryu et al., “Enhancement of the thermoelectric performance of Bi_0.4Sb_1.6Te₃, alloys by In and Ga doping,” Journal of Electronic Materials, vol. 42, no. 7, pp. 1617–1621, 2013.
View at: Publisher Site | Google Scholar

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Copyright © 2023 Okmin Park et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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International Journal of Energy Research

Enhanced Thermoelectric Performance of Lightly Pb-Doped Sb2Te3 Polycrystalline Alloys for Power Generation in Midtemperature Range

Abstract

1. Introduction

2. Experimental Methods

3. Results and Discussion

4. Conclusion

Data Availability

Conflicts of Interest

Authors’ Contributions

Acknowledgments

Supplementary Materials

References

Copyright

Enhanced Thermoelectric Performance of Lightly Pb-Doped Sb₂Te₃ Polycrystalline Alloys for Power Generation in Midtemperature Range