Energy balance equation and the boundary conditions to it are obtained in the general case. It is shown that only two sources of heat occur. There are the Joule source of heat and the Thomson source of heat. Any Peltier's source of heating or cooling is absent. It is shown that the Thomson's coefficient coincides with the Seebec coefficient. The one-dimensional model of thermoelectric module is suggested, and the temperature distribution with its minimal value are obtained in it for thermoelectric cooling. This model represents the structure composed from the different and homogeneous semiconductors. It is supposed that cooling occurs due to the classic Peltier's effect, and the thermoelectric module operates in the mode when no external thermal load is applied
{"title":"Minimal Temperature of Thermoelectric Cooling: Adiabatic Approximation","authors":"Y. Gurevich, I. Lashkevych, G. Logvinov","doi":"10.1109/ICT.2006.331364","DOIUrl":"https://doi.org/10.1109/ICT.2006.331364","url":null,"abstract":"Energy balance equation and the boundary conditions to it are obtained in the general case. It is shown that only two sources of heat occur. There are the Joule source of heat and the Thomson source of heat. Any Peltier's source of heating or cooling is absent. It is shown that the Thomson's coefficient coincides with the Seebec coefficient. The one-dimensional model of thermoelectric module is suggested, and the temperature distribution with its minimal value are obtained in it for thermoelectric cooling. This model represents the structure composed from the different and homogeneous semiconductors. It is supposed that cooling occurs due to the classic Peltier's effect, and the thermoelectric module operates in the mode when no external thermal load is applied","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129888165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report results of conductivity and Seebeck coefficient calculations for TiCo1-xCuxSb alloys, as well as their comparison with experimental data. TiCoSb crystallizes in a half-Heusler crystal structure. As revealed from experimental measurements by Horyn et al., this type of structure does not change with Cu doping until x = 0.5. Moreover, lattice constant changes also very slightly and not-monotonically for 0 < x < 0.5, varying less then 0.001 nm. Therefore, we decided to use fixed lattice constant a = 0.58819 nm for all Cu concentrations. In TiCo1-xCuxSb a semiconductor-metal phase transition is observed upon even very small Cu doping. This is connected with the fact, that Fermi level in TiCoSb is located at the top of valence band. When the number of electrons in the system grows, Fermi energy crosses energy gap (which is about 1 eV) and enters conduction band. Also Seebeck coefficient increases rapidly with x from about -350 muV/K in TiCoSb to almost zero for x = 0.5, but it doesn't change the sign. All calculations were performed within Korringa-Kohn-Rostoker (KKR) method [Bansil et al., 1990 and 1999] with coherent potential approximation (CPA) [Soven, 1967] and [Kaprzyk and Bansil, 1990]
{"title":"Residual conductivity and Seebeck coefficient calculations in TiCo1-xCuxSb alloys","authors":"T. Stopa, J. Toboła, S. Kaprzyk","doi":"10.1109/ICT.2006.331298","DOIUrl":"https://doi.org/10.1109/ICT.2006.331298","url":null,"abstract":"We report results of conductivity and Seebeck coefficient calculations for TiCo1-xCuxSb alloys, as well as their comparison with experimental data. TiCoSb crystallizes in a half-Heusler crystal structure. As revealed from experimental measurements by Horyn et al., this type of structure does not change with Cu doping until x = 0.5. Moreover, lattice constant changes also very slightly and not-monotonically for 0 < x < 0.5, varying less then 0.001 nm. Therefore, we decided to use fixed lattice constant a = 0.58819 nm for all Cu concentrations. In TiCo1-xCuxSb a semiconductor-metal phase transition is observed upon even very small Cu doping. This is connected with the fact, that Fermi level in TiCoSb is located at the top of valence band. When the number of electrons in the system grows, Fermi energy crosses energy gap (which is about 1 eV) and enters conduction band. Also Seebeck coefficient increases rapidly with x from about -350 muV/K in TiCoSb to almost zero for x = 0.5, but it doesn't change the sign. All calculations were performed within Korringa-Kohn-Rostoker (KKR) method [Bansil et al., 1990 and 1999] with coherent potential approximation (CPA) [Soven, 1967] and [Kaprzyk and Bansil, 1990]","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129067202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Min Chen, L. Rosendahl, I. Bach, T. Condra, J. Pedersen
A thermoelectric generator (TEG) usually works in dynamic operating conditions due to the time change, in real applications, of the electric load and hot or cold temperatures. Thus understanding transient thermal and electrical behavior of the device, besides the steady-state behavior, is important in order to investigate the global device performance. The major objective of this work is to describe the transient behavior of TEG operating in high temperature environments through a SPICE model based on an electrothermal analogy. The SPICE model presented is derived from a one dimensional (1-D) heat transfer differential equation. An important feature of the model is its ability to calculate the temperature profile taking the real temperature dependence of the materials properties into account. This feature is essential in simulating TEG exposed to a large temperature difference. In combination with considering the finite heat transfer rate at the interface between TEG and thermal ambient, the model is able to reflect the thermo-electric coupled multi-field system effect of TEG. A test rig is developed for verifying the proposed model. Commercially available TEG is tested with respect to stabilizing time under sharply changed electric load. The preliminary results of experiments and modeling are analyzed. It is expected that the model presented can assist, not only in the optimal design of TEG itself, but also in the evaluation of the whole energy system
{"title":"Transient Behavior Study of Thermoelectric Generators through an Electro-thermal Model Using SPICE","authors":"Min Chen, L. Rosendahl, I. Bach, T. Condra, J. Pedersen","doi":"10.1109/ICT.2006.331335","DOIUrl":"https://doi.org/10.1109/ICT.2006.331335","url":null,"abstract":"A thermoelectric generator (TEG) usually works in dynamic operating conditions due to the time change, in real applications, of the electric load and hot or cold temperatures. Thus understanding transient thermal and electrical behavior of the device, besides the steady-state behavior, is important in order to investigate the global device performance. The major objective of this work is to describe the transient behavior of TEG operating in high temperature environments through a SPICE model based on an electrothermal analogy. The SPICE model presented is derived from a one dimensional (1-D) heat transfer differential equation. An important feature of the model is its ability to calculate the temperature profile taking the real temperature dependence of the materials properties into account. This feature is essential in simulating TEG exposed to a large temperature difference. In combination with considering the finite heat transfer rate at the interface between TEG and thermal ambient, the model is able to reflect the thermo-electric coupled multi-field system effect of TEG. A test rig is developed for verifying the proposed model. Commercially available TEG is tested with respect to stabilizing time under sharply changed electric load. The preliminary results of experiments and modeling are analyzed. It is expected that the model presented can assist, not only in the optimal design of TEG itself, but also in the evaluation of the whole energy system","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123029505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geothermal and solar heat are attractive and environmentally clean energy sources for future power systems where solid state generators may become more important. In this paper, a generator model for such a novel conversion system is presented. Benefits and constraints are shown using a thermoelectric generator for solid state power conversion. For system efficiency improvement and power maximization, both thermoelectric materials and dimensions of thermoelectric generators have to be optimized. Heat losses of the thermoelectric generator can partially be recovered for building heating or water heating. Therefore, meaningful system assemblies exist to deal with the relatively low conversion efficiency of the thermoelectric generator. However, there are different limits in addition to thermoelectric materials which need to be taken into account in the generator design process
{"title":"Thermoelectric Conversion System based on Geothermal and Solar Heat","authors":"C. Eisenhut, A. Bitschi","doi":"10.1109/ICT.2006.331345","DOIUrl":"https://doi.org/10.1109/ICT.2006.331345","url":null,"abstract":"Geothermal and solar heat are attractive and environmentally clean energy sources for future power systems where solid state generators may become more important. In this paper, a generator model for such a novel conversion system is presented. Benefits and constraints are shown using a thermoelectric generator for solid state power conversion. For system efficiency improvement and power maximization, both thermoelectric materials and dimensions of thermoelectric generators have to be optimized. Heat losses of the thermoelectric generator can partially be recovered for building heating or water heating. Therefore, meaningful system assemblies exist to deal with the relatively low conversion efficiency of the thermoelectric generator. However, there are different limits in addition to thermoelectric materials which need to be taken into account in the generator design process","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123077534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We explore the electronic properties of selenium doped bismuth-antimony (Bi-Sb-Se) system and present a model of the conduction band edge structure of this system. Polycrystalline Bi1-xSb xSey samples were synthesized by fusion method. The electron concentration n estimated from RH increases with increasing Se concentration below y < 0.003, while the n is saturated in the range of Se concentration 0.003 les y les 0.1 This result indicates that the Fermi level is pinned by the Se level for the samples with y ges 0.003. We find that the values of Seebeck coefficient S for all samples change in the wide temperature range according to |S| = An -0.67T, the proportionality factors A being independent of Se concentration y . It confirms that the electronic properties of the Bi-Sb-Se system can be understood by three dimensional nearly free electrons in a parabolic conduction band. Based on these results, we will discuss a strategy to improve the thermoelectric performance of low-temperature thermoelectric materials
{"title":"Electronic Properties of Low-Temperature Thermoelectric Materials: Selenium Doped Bismuth-Antimony Alloys","authors":"M. Koyano, R. Hokaku","doi":"10.1109/ICT.2006.331340","DOIUrl":"https://doi.org/10.1109/ICT.2006.331340","url":null,"abstract":"We explore the electronic properties of selenium doped bismuth-antimony (Bi-Sb-Se) system and present a model of the conduction band edge structure of this system. Polycrystalline Bi1-xSb xSey samples were synthesized by fusion method. The electron concentration n estimated from RH increases with increasing Se concentration below y < 0.003, while the n is saturated in the range of Se concentration 0.003 les y les 0.1 This result indicates that the Fermi level is pinned by the Se level for the samples with y ges 0.003. We find that the values of Seebeck coefficient S for all samples change in the wide temperature range according to |S| = An -0.67T, the proportionality factors A being independent of Se concentration y . It confirms that the electronic properties of the Bi-Sb-Se system can be understood by three dimensional nearly free electrons in a parabolic conduction band. Based on these results, we will discuss a strategy to improve the thermoelectric performance of low-temperature thermoelectric materials","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124920236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Blangero, M. Pollet, D. Carlier, J. Darriet, C. Delmas, R. Decourt, J. Doumerc
Strong thermoelectric power (TEP) can be achieved in semiconducting oxides when a low carrier density is created by appropriate atomic substitutions or intercalations, but the electrical resistivity remains too large. Actually, oxides such as layered cobaltites for which the best balance between high TEP and small resistivity is reached contain a large concentration of strongly correlated carriers. However, the origin of the large TEP values still remains an open question. In mixed valence oxides two main transport mechanisms are generally involved: either a metallic type transport with a mean free path larger than that predicted by the Ioffe-Regel limit or a hopping type transport. In the first case, according to Mott's equation, large TEP values could result from peculiar energy dependence of the density of states and relaxation time at the Fermi level; in the second case TEP can be calculated using Heikes formula. In both cases, TEP can be enhanced by spin entropy effects mainly expected for spin polarized metallic oxides (or half metals) rather than Pauli metals. For hopping transport an additional term in Heikes formula arising from the spin as well as orbital degeneracy must be taken into account. The specificity of the Co3+ ions (3d6) that can exhibit three different electronic configurations (S = 0, S = 1 and S = 2) in oxides, depending on the interplay of exchange and crystal field energies, as well as the dimensionality of the crystal structure, the site symmetry and correlation effects is also discussed. The behavior of recently investigated potassium-intercalated 2D-cobaltites is compared to that of the corresponding sodium oxides
当通过适当的原子取代或插入产生低载流子密度时，半导体氧化物可以实现强热电功率(TEP)，但电阻率仍然太大。实际上，在高TEP和小电阻率之间达到最佳平衡的氧化物，如层状钴酸盐，含有高浓度的强相关载流子。然而，大TEP值的来源仍然是一个悬而未决的问题。在混合价氧化物中，通常涉及两种主要的输运机制:平均自由程大于Ioffe-Regel极限预测的金属型输运或跳变型输运。在第一种情况下，根据莫特方程，大TEP值可能是由于费米能级上态密度和弛豫时间的特殊能量依赖;在第二种情况下，TEP可以用Heikes公式计算。在这两种情况下，TEP都可以通过自旋极化金属氧化物(或半金属)而不是泡利金属的自旋熵效应来增强。对于跳跃输运，必须考虑由自旋和轨道简并引起的海克斯公式中的附加项。本文还讨论了Co3+离子(3d6)在氧化物中表现出三种不同电子构型(S = 0, S = 1和S = 2)的特殊性，这取决于交换和晶体场能的相互作用，以及晶体结构的维数、位对称和相关效应。最近研究的钾插层2d钴酸盐的行为与相应的氧化钠的行为进行了比较
{"title":"Electronic Properties of 2D Alkali Cobaltites and Related Oxides","authors":"M. Blangero, M. Pollet, D. Carlier, J. Darriet, C. Delmas, R. Decourt, J. Doumerc","doi":"10.1109/ICT.2006.331268","DOIUrl":"https://doi.org/10.1109/ICT.2006.331268","url":null,"abstract":"Strong thermoelectric power (TEP) can be achieved in semiconducting oxides when a low carrier density is created by appropriate atomic substitutions or intercalations, but the electrical resistivity remains too large. Actually, oxides such as layered cobaltites for which the best balance between high TEP and small resistivity is reached contain a large concentration of strongly correlated carriers. However, the origin of the large TEP values still remains an open question. In mixed valence oxides two main transport mechanisms are generally involved: either a metallic type transport with a mean free path larger than that predicted by the Ioffe-Regel limit or a hopping type transport. In the first case, according to Mott's equation, large TEP values could result from peculiar energy dependence of the density of states and relaxation time at the Fermi level; in the second case TEP can be calculated using Heikes formula. In both cases, TEP can be enhanced by spin entropy effects mainly expected for spin polarized metallic oxides (or half metals) rather than Pauli metals. For hopping transport an additional term in Heikes formula arising from the spin as well as orbital degeneracy must be taken into account. The specificity of the Co3+ ions (3d6) that can exhibit three different electronic configurations (S = 0, S = 1 and S = 2) in oxides, depending on the interplay of exchange and crystal field energies, as well as the dimensionality of the crystal structure, the site symmetry and correlation effects is also discussed. The behavior of recently investigated potassium-intercalated 2D-cobaltites is compared to that of the corresponding sodium oxides","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131160244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bulk Bi and Bi-Sb are of interest for solid state cooling applications. Composites of these materials may show to be superior to bulk materials in these applications, because of quantum confinement and phonon scattering. Also, there is an interested in miniature devices and nanoscale coolers that interface with them. We have studied the thermopower of single Bi nanowires of diameters in the range 50-500 nm. The nanowires are fabricated as single strands of thermoelectric material, that are monocrystalline, in a glass envelope (a fiber). We observe that the thermopower peaks of around +90 muV/K at around 50 K. These values are the largest for any electrical-conductor in this temperature range. We interpret these effects in terms of a phenomenological model where boundary scattering is more effective for electrons than for holes. The temperature and the value of thermopower maximum depend sensitively with magnetic fields and Te doping. Also, stretching the fibers cause uniaxial stresses similar to that of "negative pressure" [Hicks, LD, et. al., 1993] that drives an electron topological transition, similarly to the case of Bi-Te [Lin, Y-M, et. al., 2000]. Near the ETT point we recorded very large oscillations of the thermopower, that are associated with the Landau levels in the nanowires. Our work focuses in the development a mathematical model to optimize the thermoelectric figure of merit considering magnetic field, doping, and pressure
{"title":"Diffusion Thermopower Of Bismuth Nanowires And The Role Of Carrier's Boundary Scattering. Doping, Pressure and Magnetic Field Studies","authors":"A. Nikolaeva, T. Huber, L. Konopko","doi":"10.1109/ICT.2006.331256","DOIUrl":"https://doi.org/10.1109/ICT.2006.331256","url":null,"abstract":"Bulk Bi and Bi-Sb are of interest for solid state cooling applications. Composites of these materials may show to be superior to bulk materials in these applications, because of quantum confinement and phonon scattering. Also, there is an interested in miniature devices and nanoscale coolers that interface with them. We have studied the thermopower of single Bi nanowires of diameters in the range 50-500 nm. The nanowires are fabricated as single strands of thermoelectric material, that are monocrystalline, in a glass envelope (a fiber). We observe that the thermopower peaks of around +90 muV/K at around 50 K. These values are the largest for any electrical-conductor in this temperature range. We interpret these effects in terms of a phenomenological model where boundary scattering is more effective for electrons than for holes. The temperature and the value of thermopower maximum depend sensitively with magnetic fields and Te doping. Also, stretching the fibers cause uniaxial stresses similar to that of \"negative pressure\" [Hicks, LD, et. al., 1993] that drives an electron topological transition, similarly to the case of Bi-Te [Lin, Y-M, et. al., 2000]. Near the ETT point we recorded very large oscillations of the thermopower, that are associated with the Landau levels in the nanowires. Our work focuses in the development a mathematical model to optimize the thermoelectric figure of merit considering magnetic field, doping, and pressure","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131242937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
X. Huang, Y. Miyazaki, K. Yubuta, Y. Oide, T. Kajitani
Large and high-quality single crystal flakes of [Ca2CoO 3]0.62[CoO2] compound were grown from Co3O4 and CaCO3 reagents with chloride flux. Typical single crystal flake size is about 5times5times0.02 mm 3. Obtained crystal flakes were consolidated by the spark plasma sintering (SPS) technique at 1100 K for 1 h. Grain alignment was checked by XRD and also was confirmed by SEM observations on the fractured surface. At 1000 K electrical conductivity of the textured ceramics is about 270 Scm-1, twice as higher than that of powder sample sintered by the SPS procedure. ZT value of the textured sample reaches 0.4 at 1000 K, being 50% improvement relative to the powder-sintered sample, though thermal conductivity increases simultaneously
{"title":"The thermoelectric properties of [Ca2CoO3]0.62[CoO2] textured ceramics","authors":"X. Huang, Y. Miyazaki, K. Yubuta, Y. Oide, T. Kajitani","doi":"10.1109/ICT.2006.331287","DOIUrl":"https://doi.org/10.1109/ICT.2006.331287","url":null,"abstract":"Large and high-quality single crystal flakes of [Ca<sub>2</sub>CoO <sub>3</sub>]<sub>0.62</sub>[CoO<sub>2</sub>] compound were grown from Co<sub>3</sub>O<sub>4</sub> and CaCO<sub>3</sub> reagents with chloride flux. Typical single crystal flake size is about 5times5times0.02 mm <sup>3</sup>. Obtained crystal flakes were consolidated by the spark plasma sintering (SPS) technique at 1100 K for 1 h. Grain alignment was checked by XRD and also was confirmed by SEM observations on the fractured surface. At 1000 K electrical conductivity of the textured ceramics is about 270 Scm<sup>-1</sup>, twice as higher than that of powder sample sintered by the SPS procedure. ZT value of the textured sample reaches 0.4 at 1000 K, being 50% improvement relative to the powder-sintered sample, though thermal conductivity increases simultaneously","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"372 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127583573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chunquan Long, Xufeng Hou, Y. Gelbstein, Jianzhong Zhang, B. Ren, Zeshen Wang
Lead telluride is traditional thermoelectric material at middle temperature and widely applied for electricity generation. They have been attracting many scientists to research on. The paper reports an N-type PbTe materials with high thermoelectric performances based on the traditional halogen-doping mechanism with additional indium. The PbTe based materials doped indium and PbI2 are prepared by powder metallurgy technology. We use an intermediate frequency induced furnace for primary alloy preparation. The alloy shows very homogeneous with the desired composition. Then, the comminuted powder particles are hot pressed under certain temperature, pressure and so on. The prepared samples have been examined by FETEM and their thermoelectric properties have been measured. The results indicate that doping with the appropriate PbI2 and indium leads to remarkable improvement of the thermoelectric properties, and we gained high figure of merit over a wide temperature range
{"title":"Preparation and Thermoelectric Properties of N-type PbTe Doped with In and PbI2","authors":"Chunquan Long, Xufeng Hou, Y. Gelbstein, Jianzhong Zhang, B. Ren, Zeshen Wang","doi":"10.1109/ICT.2006.331277","DOIUrl":"https://doi.org/10.1109/ICT.2006.331277","url":null,"abstract":"Lead telluride is traditional thermoelectric material at middle temperature and widely applied for electricity generation. They have been attracting many scientists to research on. The paper reports an N-type PbTe materials with high thermoelectric performances based on the traditional halogen-doping mechanism with additional indium. The PbTe based materials doped indium and PbI2 are prepared by powder metallurgy technology. We use an intermediate frequency induced furnace for primary alloy preparation. The alloy shows very homogeneous with the desired composition. Then, the comminuted powder particles are hot pressed under certain temperature, pressure and so on. The prepared samples have been examined by FETEM and their thermoelectric properties have been measured. The results indicate that doping with the appropriate PbI2 and indium leads to remarkable improvement of the thermoelectric properties, and we gained high figure of merit over a wide temperature range","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"41 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132693004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaofeng Wu, Guiying Xu, Ya-dong Xu, Chunyan Zhang, C. Ge
P-type (Sb2Te3)75(Bi2Te3 )25+xTe (x = 2, 3, 4, 5, wt %) was prepared by single-axis hot pressing. The performances of the samples were reported and discussed in this paper. SEM was made to observe the typical microstructure. Density and bending strength were observed for analyzing the dependence of content of telluride on strength. Electric conductivity and Seebeck coefficient were measured, power factor was calculated, and telluride dependence of thermoelectric properties was analyzed. By analysis, we found that there were evident relation among content of telluride dependence of morphology, density, bending strength and thermoelectric properties. Power factor of Bi-Sb-Te doped with 4wt% telluride was the highest, with alpha = 0.209mV7K, sigma = 90.253(Omega-mm)-1, alpha2sigma =3.951 mW/K 2middotm
{"title":"Mechanical and Thermoelectric Performance of p-type Bi-Sb-Te Prepared by Hot Pressing","authors":"Xiaofeng Wu, Guiying Xu, Ya-dong Xu, Chunyan Zhang, C. Ge","doi":"10.1109/ICT.2006.331226","DOIUrl":"https://doi.org/10.1109/ICT.2006.331226","url":null,"abstract":"P-type (Sb<sub>2</sub>Te<sub>3</sub>)<sub>75</sub>(Bi<sub>2</sub>Te<sub>3 </sub>)<sub>25</sub>+xTe (x = 2, 3, 4, 5, wt %) was prepared by single-axis hot pressing. The performances of the samples were reported and discussed in this paper. SEM was made to observe the typical microstructure. Density and bending strength were observed for analyzing the dependence of content of telluride on strength. Electric conductivity and Seebeck coefficient were measured, power factor was calculated, and telluride dependence of thermoelectric properties was analyzed. By analysis, we found that there were evident relation among content of telluride dependence of morphology, density, bending strength and thermoelectric properties. Power factor of Bi-Sb-Te doped with 4wt% telluride was the highest, with alpha = 0.209mV7K, sigma = 90.253(Omega-mm)<sup>-1</sup>, alpha<sup>2</sup>sigma =3.951 mW/K <sup>2</sup>middotm","PeriodicalId":346555,"journal":{"name":"2006 25th International Conference on Thermoelectrics","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114651792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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