Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519993
J. Caylor, K. Coonley, J. Stuart, S. Nangaoy, T. Colpitts, R. Venkatasubramanian
The fabrication of n-type PbTe/PbTe/sub 0.75/Se/sub 0.25/ structures using a simple evaporation technique has yielded high-quality superlattice films, a significant reduction in lattice thermal conductivity and potentially enhanced thermoelectric device performance, compared to standard PbTeSe alloys. The room temperature lattice thermal conductivity of PbTeSe alloys have been reduced by a factor of two or more using PbTe/PbTeSe superlattices in the cross-plane direction. Using this advantage, we have begun characterizing the cross-plane ZT of PbTe/PbTeSe superlattice devices, including the development of appropriate Ohmic contacts for the PbTe-material system. We will discuss various device process technologies for improved Ohmic contacts. The room-temperature measurement of cross-plane figure-of-merit in n-type PbTe/PbTe/sub 0.75/Se/sub 0.25/ device structure by the transient method will be reported. Also, these results will be combined with temperature dependent measurements of in-plane resistivity and Seebeck coefficient to yield evidence of enhanced thermoelectric performance. The results from similar p-type films, as well as preliminary data on heteroepitaxial films grown on Bi/sub 2/Te/sub 3/ will be discussed.
{"title":"Developing PbTe-based superlattice structures with enhanced thermoelectric performance","authors":"J. Caylor, K. Coonley, J. Stuart, S. Nangaoy, T. Colpitts, R. Venkatasubramanian","doi":"10.1109/ICT.2005.1519993","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519993","url":null,"abstract":"The fabrication of n-type PbTe/PbTe/sub 0.75/Se/sub 0.25/ structures using a simple evaporation technique has yielded high-quality superlattice films, a significant reduction in lattice thermal conductivity and potentially enhanced thermoelectric device performance, compared to standard PbTeSe alloys. The room temperature lattice thermal conductivity of PbTeSe alloys have been reduced by a factor of two or more using PbTe/PbTeSe superlattices in the cross-plane direction. Using this advantage, we have begun characterizing the cross-plane ZT of PbTe/PbTeSe superlattice devices, including the development of appropriate Ohmic contacts for the PbTe-material system. We will discuss various device process technologies for improved Ohmic contacts. The room-temperature measurement of cross-plane figure-of-merit in n-type PbTe/PbTe/sub 0.75/Se/sub 0.25/ device structure by the transient method will be reported. Also, these results will be combined with temperature dependent measurements of in-plane resistivity and Seebeck coefficient to yield evidence of enhanced thermoelectric performance. The results from similar p-type films, as well as preliminary data on heteroepitaxial films grown on Bi/sub 2/Te/sub 3/ will be discussed.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123360516","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519917
M. Ohta, S. Hirai, H. Kato, H. Asahi
The electrical resistivity, thermopower, thermal conductivity measurements have been made on tetragonal La/sub 10/S/sub 14/O. The electrical resistivity was measured during heating and successive cooling through 300 and 1000 K to investigate the high-temperature phase stability. The measurements were carried out in the vacuum chamber pumped down to 1.0 Pa. The electrical properties of La/sub 10/S/sub 14/O are changed dramatically through heat treatment. As annealing time increases, the electrical resistivity increases abruptly and then decreases gradually. However, it seems that this phase can be stabilized by a small addition of Ti. In the electrical resistivity of La/sub 10/S/sub 14/O with Ti, the cooling curve agrees with heating curve. Moreover, the ZT value increases abruptly with increasing temperature, reaching a value of 0.18 at 1000 K. The improvement with respect to the thermoelectric properties of the La/sub 10/S/sub 14/O is realized by a small addition of Ti.
{"title":"Thermoelectric properties and phase stability of La/sub 10/S/sub 14/O","authors":"M. Ohta, S. Hirai, H. Kato, H. Asahi","doi":"10.1109/ICT.2005.1519917","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519917","url":null,"abstract":"The electrical resistivity, thermopower, thermal conductivity measurements have been made on tetragonal La/sub 10/S/sub 14/O. The electrical resistivity was measured during heating and successive cooling through 300 and 1000 K to investigate the high-temperature phase stability. The measurements were carried out in the vacuum chamber pumped down to 1.0 Pa. The electrical properties of La/sub 10/S/sub 14/O are changed dramatically through heat treatment. As annealing time increases, the electrical resistivity increases abruptly and then decreases gradually. However, it seems that this phase can be stabilized by a small addition of Ti. In the electrical resistivity of La/sub 10/S/sub 14/O with Ti, the cooling curve agrees with heating curve. Moreover, the ZT value increases abruptly with increasing temperature, reaching a value of 0.18 at 1000 K. The improvement with respect to the thermoelectric properties of the La/sub 10/S/sub 14/O is realized by a small addition of Ti.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123642094","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}
Pub Date : 2005-06-19DOI: 10.2320/MATERTRANS.47.1453
H. Muta, T. Yamaguchi, K. Kurosaki, S. Yamanaka
The thermoelectric properties of titanium substituted ZrNiSn have been measured from room temperature to 1000 K. The samples were prepared by arc melting followed by spark plasma sintering (SPS) technique. High SPS temperature increased the homogeneity of titanium substituted sample, result at increase of the electrical conductivity without deterioration of the Seebeck coefficient. Zr/sub 0.7/Ti/sub 0.3/NiSn showed higher power factor than pure ZrNiSn, the value reached 4 mW/mK/sup 2/ at 700 K. The SPS temperature had little influence on the thermal conductivity. However, the titanium substituted sample decomposed upon annealing at high temperature. Thus appropriate heat and preparation treatment appeared to be necessary for the samples containing titanium. Highest ZT was obtained for Zr/sub 0.7/Ti/sub 0.3/NiSn, equal to 0.48 at 800 K.
{"title":"Thermoelectric properties of ZrNiSn based half Heusler compounds","authors":"H. Muta, T. Yamaguchi, K. Kurosaki, S. Yamanaka","doi":"10.2320/MATERTRANS.47.1453","DOIUrl":"https://doi.org/10.2320/MATERTRANS.47.1453","url":null,"abstract":"The thermoelectric properties of titanium substituted ZrNiSn have been measured from room temperature to 1000 K. The samples were prepared by arc melting followed by spark plasma sintering (SPS) technique. High SPS temperature increased the homogeneity of titanium substituted sample, result at increase of the electrical conductivity without deterioration of the Seebeck coefficient. Zr/sub 0.7/Ti/sub 0.3/NiSn showed higher power factor than pure ZrNiSn, the value reached 4 mW/mK/sup 2/ at 700 K. The SPS temperature had little influence on the thermal conductivity. However, the titanium substituted sample decomposed upon annealing at high temperature. Thus appropriate heat and preparation treatment appeared to be necessary for the samples containing titanium. Highest ZT was obtained for Zr/sub 0.7/Ti/sub 0.3/NiSn, equal to 0.48 at 800 K.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123732733","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519876
Jianhua Zhou, Chuangui Jin, J. Seol, Xiaoguang Li, Lio Shi
We have measured the thermoelectric properties of electrochemically deposited bismuth telluride (Bi/sub x/Te/sub 1-x/) nanowires with different atomic ratio or x. In this paper, we report the measurement method and the results for an individual nanowire from a batch with x found to be about 0.54. The Seebeck coefficient of the nanowire was found to be -30 /spl mu/V/K at temperature 300 K. The obtained electrical conductivity of the nanowire showed unusually weak temperature dependence, and the value at 300 K was only 5.6% lower than that of bulk Bi/sub 0.485/Te/sub 0.515/ crystal. The thermal conductivity of the nanowires was found to be 44% lower than that of bulk Bi/sub 0.485/Te/sub 0.515/ crystals.
{"title":"Measurement of thermoelectric properties of individual bismuth telluride nanowires","authors":"Jianhua Zhou, Chuangui Jin, J. Seol, Xiaoguang Li, Lio Shi","doi":"10.1109/ICT.2005.1519876","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519876","url":null,"abstract":"We have measured the thermoelectric properties of electrochemically deposited bismuth telluride (Bi/sub x/Te/sub 1-x/) nanowires with different atomic ratio or x. In this paper, we report the measurement method and the results for an individual nanowire from a batch with x found to be about 0.54. The Seebeck coefficient of the nanowire was found to be -30 /spl mu/V/K at temperature 300 K. The obtained electrical conductivity of the nanowire showed unusually weak temperature dependence, and the value at 300 K was only 5.6% lower than that of bulk Bi/sub 0.485/Te/sub 0.515/ crystal. The thermal conductivity of the nanowires was found to be 44% lower than that of bulk Bi/sub 0.485/Te/sub 0.515/ crystals.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122601035","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519978
L. N. Lukyanova, V. Kutasov, V. Popov, P. Konstantinov
Galvanomagnetic properties of multicomponent solid solutions of n-Bi/sub 2-x/Sb/sub x/Te/sub 3-y-z/Se/sub y/S/sub z/ composition were studied in weak and intermediate magnetic fields. Components of the effective mass tensor m/sub i//m/sub j/ were determined in the framework of the many-valley energy spectrum model using the isotropic scattering mechanism for a variety of solid solution compositions and electron concentrations. The influence of constant-energy surface parameters on the solid solutions thermoelectric efficiency was analyzed.
{"title":"Galvanomagnetic properties of multicomponent solid solutions based on Bi and Sb chalcogenides","authors":"L. N. Lukyanova, V. Kutasov, V. Popov, P. Konstantinov","doi":"10.1109/ICT.2005.1519978","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519978","url":null,"abstract":"Galvanomagnetic properties of multicomponent solid solutions of n-Bi/sub 2-x/Sb/sub x/Te/sub 3-y-z/Se/sub y/S/sub z/ composition were studied in weak and intermediate magnetic fields. Components of the effective mass tensor m/sub i//m/sub j/ were determined in the framework of the many-valley energy spectrum model using the isotropic scattering mechanism for a variety of solid solution compositions and electron concentrations. The influence of constant-energy surface parameters on the solid solutions thermoelectric efficiency was analyzed.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130400851","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519878
E. Guilmeau, M. Pollet, D. Grebille, M. Hervieu, H. Muguerra, R. Cloots, M. Mikami, R. Funahashi
The thermopower and the electrical resistivity of [BiCaO/sub 2/]/sub 2/[CoO/sub 2/]/sub 1.69/ and corresponding iodine intercalated single crystals have been measured. Upon intercalation, the thermopower is drastically decreased, indicating that there is a hole doping by charge transfer from the intercalated iodine layer to the hexagonal CoO/sub 2/ layer. The resistivity is increased due to stacking faults and disordered structures. Structural analyses confirmed the stacking scheme along the c direction, with the localisation of iodine between the [BiO] double layers. The effect of intercalation on the thermoelectric properties suggested discussions from the view point of hole doping and nano-block layer coupling effect.
{"title":"Structural features and transport properties of iodine intercalated misfit layer [BiCaO/sub 2/]/sub 2/[CoO/sub 2/]/sub 1.69/ single crystals","authors":"E. Guilmeau, M. Pollet, D. Grebille, M. Hervieu, H. Muguerra, R. Cloots, M. Mikami, R. Funahashi","doi":"10.1109/ICT.2005.1519878","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519878","url":null,"abstract":"The thermopower and the electrical resistivity of [BiCaO/sub 2/]/sub 2/[CoO/sub 2/]/sub 1.69/ and corresponding iodine intercalated single crystals have been measured. Upon intercalation, the thermopower is drastically decreased, indicating that there is a hole doping by charge transfer from the intercalated iodine layer to the hexagonal CoO/sub 2/ layer. The resistivity is increased due to stacking faults and disordered structures. Structural analyses confirmed the stacking scheme along the c direction, with the localisation of iodine between the [BiO] double layers. The effect of intercalation on the thermoelectric properties suggested discussions from the view point of hole doping and nano-block layer coupling effect.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133769116","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519884
N. Koseki, K. Machida, K. Yamamoto, Y. Oikawa, C. Kim, H. Ozaki
Effects of Mn-Ni co-substitution were investigated on the thermoelectric properties of sintered magnetite (Fe/sub 3/O/sub 4/). Following the previous study, investigations were focused on the x dependence for 0/spl les/x/spl les/0.4 with y=2/3, and y dependence for 0/spl les/y/spl les/1 with x=0.2, in (Mn/sub y/Ni/sub 1-y/)/sub x/Fe/sub 3-x/O/sub 4/. Thermoelectric power factor manifested a maximum near x=0.2 and y=2/3, exceeding that of magnetite, due to a remarkable behavior of electrical resistivity in the x and y dependences. This behavior was shown to originate from that of the mobility in the framework of analysis by small-polaron hopping model. In this model, the hopping energy was shown to change at the Neel temperature.
{"title":"Thermoelectric properties of sintered (Mn/sub y/Ni/sub 1-y/)/sub x/Fe/sub 3-x/O/sub 4/","authors":"N. Koseki, K. Machida, K. Yamamoto, Y. Oikawa, C. Kim, H. Ozaki","doi":"10.1109/ICT.2005.1519884","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519884","url":null,"abstract":"Effects of Mn-Ni co-substitution were investigated on the thermoelectric properties of sintered magnetite (Fe/sub 3/O/sub 4/). Following the previous study, investigations were focused on the x dependence for 0/spl les/x/spl les/0.4 with y=2/3, and y dependence for 0/spl les/y/spl les/1 with x=0.2, in (Mn/sub y/Ni/sub 1-y/)/sub x/Fe/sub 3-x/O/sub 4/. Thermoelectric power factor manifested a maximum near x=0.2 and y=2/3, exceeding that of magnetite, due to a remarkable behavior of electrical resistivity in the x and y dependences. This behavior was shown to originate from that of the mobility in the framework of analysis by small-polaron hopping model. In this model, the hopping energy was shown to change at the Neel temperature.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132092047","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519950
G. J. Snyder, P. Stephens, S. Haile
The structure of the thermoelectric Zn/sub 4/Sb/sub 3/ is refined using synchrotron X-ray powder diffraction data collected at wavelengths both near to and relatively far from the Zn adsorption edge. In agreement with earlier studies, the compound crystallized in a trigonal structure, space group R~3c with a = 12.2406(3)/spl Aring/, c = 12.4361(3)/spl Aring/ at room temperature, and there are three primary sites in the asymmetric unit. Each site contains only one atomic species, in contrast to many previous studies. The primary Zn (36f) site is slightly less than fully occupied, whereas the two Sb sites (18e and 12c) are fully occupied. In addition, several Zn interstitial sites (36f) with low occupancies (>5%) are also present. The results are in agreement with the model proposed by Snyder, as opposed to that originally proposed by Mayer and more recently by Mozharivskyj. The refined site occupancies yield an overall stoichiometry which is consistent with that measured experimentally. The presence of interstitial Zn can be understood in terms of charge balance requirements and is likely responsible for the exceptionally low thermal conductivity of this material.
利用同步加速器x射线粉末衍射数据，在Zn吸附边附近和相对较远的波长处对热电Zn/sub 4/Sb/sub 3/的结构进行了细化。与前人的研究一致，化合物在室温下结晶为三角形结构，空间群R~3c, a = 12.2406(3)/spl Aring/， c = 12.4361(3)/spl Aring/，在不对称单元中有三个主位。与之前的许多研究不同，每个位点只包含一种原子。主Zn (36f)位点略小于完全占据，而两个Sb位点(18e和12c)则完全占据。此外，还存在几个低占位率(>5%)的Zn间隙位(36f)。结果与Snyder提出的模型一致，而不是最初由Mayer和最近由Mozharivskyj提出的模型。精确的位置占用量产生了与实验测量一致的总体化学计量。间隙锌的存在可以从电荷平衡要求的角度来理解，并且可能是这种材料异常低导热率的原因。
{"title":"Synchrotron X-ray structure refinement of Zn/sub 4/Sb/sub 3/","authors":"G. J. Snyder, P. Stephens, S. Haile","doi":"10.1109/ICT.2005.1519950","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519950","url":null,"abstract":"The structure of the thermoelectric Zn/sub 4/Sb/sub 3/ is refined using synchrotron X-ray powder diffraction data collected at wavelengths both near to and relatively far from the Zn adsorption edge. In agreement with earlier studies, the compound crystallized in a trigonal structure, space group R~3c with a = 12.2406(3)/spl Aring/, c = 12.4361(3)/spl Aring/ at room temperature, and there are three primary sites in the asymmetric unit. Each site contains only one atomic species, in contrast to many previous studies. The primary Zn (36f) site is slightly less than fully occupied, whereas the two Sb sites (18e and 12c) are fully occupied. In addition, several Zn interstitial sites (36f) with low occupancies (>5%) are also present. The results are in agreement with the model proposed by Snyder, as opposed to that originally proposed by Mayer and more recently by Mozharivskyj. The refined site occupancies yield an overall stoichiometry which is consistent with that measured experimentally. The presence of interstitial Zn can be understood in terms of charge balance requirements and is likely responsible for the exceptionally low thermal conductivity of this material.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129883277","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519882
N. Lowhorn, T. Tritt, E. Abbott, J. Kolis
The transition metal pentatellurides HfTe/sub 5/ and ZrTe/sub 5/ have been observed to possess high thermoelectric power factors and anomalous electrical transport behavior. The temperature dependence of the resistivity is semimetallic except for a large resistive peak as a function of temperature at around 75 K for HfTe/sub 5/ and 145 K for ZrTe/sub 5/. At a temperature corresponding to this peak, the thermopower crosses zero as it moves from large positive values to large negative values. Previous doping studies have shown profound and varied effects on the anomalous transport. In this study we investigate the effect on the electrical resistivity, thermopower, and magnetoresistance of doping HfTe/sub 5/ with rare-earth elements. Doping with rare-earth elements of increasing atomic number leads to a systematic suppression of the anomalous transport behavior and large magnetoresistive effect observed in the parent compound. Rare-earth doping also leads to an enhancement of the thermoelectric power factor over previously studied pentatellurides. For nominal Hf/sub 0.75/Nd/sub 0.25/Te/sub 5/ and Hf/sub 0.75/Sm/sub 0.25/Te/sub 5/, values more than a factor of 2 larger than that of the commonly used thermoelectric material Bi/sub 2/Te/sub 3/ were observed.
{"title":"Effect of rare earth doping on the thermoelectric and electrical transport properties of the transition metal pentatelluride HfTe/sub 5/","authors":"N. Lowhorn, T. Tritt, E. Abbott, J. Kolis","doi":"10.1109/ICT.2005.1519882","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519882","url":null,"abstract":"The transition metal pentatellurides HfTe/sub 5/ and ZrTe/sub 5/ have been observed to possess high thermoelectric power factors and anomalous electrical transport behavior. The temperature dependence of the resistivity is semimetallic except for a large resistive peak as a function of temperature at around 75 K for HfTe/sub 5/ and 145 K for ZrTe/sub 5/. At a temperature corresponding to this peak, the thermopower crosses zero as it moves from large positive values to large negative values. Previous doping studies have shown profound and varied effects on the anomalous transport. In this study we investigate the effect on the electrical resistivity, thermopower, and magnetoresistance of doping HfTe/sub 5/ with rare-earth elements. Doping with rare-earth elements of increasing atomic number leads to a systematic suppression of the anomalous transport behavior and large magnetoresistive effect observed in the parent compound. Rare-earth doping also leads to an enhancement of the thermoelectric power factor over previously studied pentatellurides. For nominal Hf/sub 0.75/Nd/sub 0.25/Te/sub 5/ and Hf/sub 0.75/Sm/sub 0.25/Te/sub 5/, values more than a factor of 2 larger than that of the commonly used thermoelectric material Bi/sub 2/Te/sub 3/ were observed.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132196019","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}
Pub Date : 2005-06-19DOI: 10.1109/ICT.2005.1519885
Jen-Hau Cheng, Chun-Kai Liu, Y. Chao, R. Tain
In this paper, a new thermal management application of silicon-based thermoelectric (TE) device on high power LED is unveiled. The silicon-based TE device is fabricated by the microfabrication and flip-chip assembly process. Thermal images photographed by infrared camera demonstrate the cooling function of the silicon-based TE devices. Because the LED chip is encapsulated in a package, the junction temperature of the LED chip cannot be measured directly. An electrical-thermal conversion method is used to measure the junction temperature of the high power LED. The result shows that the silicon-based thermoelectric device can effectively reduce the thermal resistance of the high power LED.
{"title":"Cooling performance of silicon-based thermoelectric device on high power LED","authors":"Jen-Hau Cheng, Chun-Kai Liu, Y. Chao, R. Tain","doi":"10.1109/ICT.2005.1519885","DOIUrl":"https://doi.org/10.1109/ICT.2005.1519885","url":null,"abstract":"In this paper, a new thermal management application of silicon-based thermoelectric (TE) device on high power LED is unveiled. The silicon-based TE device is fabricated by the microfabrication and flip-chip assembly process. Thermal images photographed by infrared camera demonstrate the cooling function of the silicon-based TE devices. Because the LED chip is encapsulated in a package, the junction temperature of the LED chip cannot be measured directly. An electrical-thermal conversion method is used to measure the junction temperature of the high power LED. The result shows that the silicon-based thermoelectric device can effectively reduce the thermal resistance of the high power LED.","PeriodicalId":422400,"journal":{"name":"ICT 2005. 24th International Conference on Thermoelectrics, 2005.","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132569301","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：