Showing papers on "Seebeck coefficient published in 2010"
TL;DR: In this article, a review summarizes the progress that has been made in recent years in developing thermoelectric materials with a high dimensionless figure of merits (ZT) and the related fabrication processes for producing nanostuctured materials.
Abstract: Thermoelectric effects enable direct conversion between thermal and electrical energy and provide an alternative route for power generation and refrigeration. Over the past ten years, the exploration of high-performance thermoelectric materials has attracted great attention from both an academic research perspective and with a view to industrial applications. This review summarizes the progress that has been made in recent years in developing thermoelectric materials with a high dimensionless figure of merits (ZT) and the related fabrication processes for producing nanostuctured materials. The challenge to develop thermoelectric materials with superior performance is to tailor the interconnected thermoelectric physical parameters — electrical conductivity, Seebeck coefficient and thermal conductivity — for a crystalline system. Nanostructures provide a chance to disconnect the linkage between thermal and electrical transport by introducing some new scattering mechanisms. Recent improvements in thermoelectric efficiency appear to be dominated by efforts to reduce the lattice thermal conductivity through nanostructural design. The materials focused in this review include Bi–Te alloys, skutterudite compounds, Ag–Pb–Sb–Te quaternary systems, half-Heusler compounds and some high-ZT oxides. Possible future strategies for developing thermoelectric materials are also discussed.
813 citations
TL;DR: This study suggests that constructing highly ordered chain structure is a novel and effective way for improving the thermoelectric properties of conducting polymers.
Abstract: Hybrid nanocomposites containing carbon nanotubes (CNTs) and ordered polyaniline (PANI) have been prepared through an in situ polymerization reaction using a single-walled nanotube (SWNT) as template and aniline as reactant. TEM, SEM, XRD, and Raman analyses show that the polyaniline grew along the surface of CNTs forming an ordered chain structure during the SWNT-directed polymerization process. The SWNT/PANI nanocomposites show both higher electrical conductivity and Seebeck coefficient as compared to pure PANI, which could be attributed to the enhanced carrier mobility in the ordered chain structures of the PANI. The maximum electrical conductivity and Seebeck coefficient of composites reach 1.25 × 104 S m−1 and 40 μV K−1, respectively, and the maximum power factor is up to 2 × 10−5 W m−1 K−2, more than 2 orders of magnitude higher than the pure polyaniline. This study suggests that constructing highly ordered chain structure is a novel and effective way for improving the thermoelectric properties of c...
589 citations
TL;DR: In this article, the optoelectronic response of a single-bilayer interface junction using photocurrent microscopy was investigated and it was shown that the generation of PC is by a photothermoelectric effect.
Abstract: We investigate the optoelectronic response of a graphene single-bilayer interface junction using photocurrent (PC) microscopy. We measure the polarity and amplitude of the PC while varying the Fermi level by tuning a gate voltage. These measurements show that the generation of PC is by a photothermoelectric effect. The PC displays a factor of approximately 10 increase at the cryogenic temperature as compared to room temperature. Assuming the thermoelectric power has a linear dependence on the temperature, the inferred graphene thermal conductivity from temperature dependent measurements has a T(1.5) dependence below approximately 100 K, which agrees with recent theoretical predictions.
566 citations
TL;DR: The crucial role of stabilizers was revealed by characterizing transport characteristics of composites synthesized by electrically conducting PEDOT:PSS and insulating gum Arabic with 1:1-1:4 weight ratios of CNT to stabilizers, and the influence of composite synthesis temperature and CNT-type and concentration on thermoelectric properties has also been studied.
Abstract: The thermoelectric properties of carbon nanotube (CNT)-filled polymer composites can be enhanced by modifying junctions between CNTs using poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), yielding high electrical conductivities (up to ∼40000 S/m) without significantly altering thermopower (or Seebeck coefficient). This is because PEDOT:PSS particles are decorated on the surface of CNTs, electrically connecting junctions between CNTs. On the other hand, thermal transport remains comparable to typical polymeric materials due to the dissimilar bonding and vibrational spectra between CNT and PEDOT:PSS. This behavior is very different from that of typical semiconductors whose thermoelectric properties are strongly correlated. The decoupled thermoelectric properties, which is ideal for developing better thermoelectric materials, are believed to be due to thermally disconnected and electrically connected contact junctions between CNTs. Carrier transport at the junction is found to be strongly...
543 citations
TL;DR: In this article, a layered oxyselenide composed of conductive (Cu2Se2) 2− layers alternately stacked with insulating (Bi2O2)2+ layers, shows an enhancement of the electrical conductivity after substituting Bi3+ by Sr2+, from 470 S 1/m−1 (BiCuSeO) to 4.8×104 S 2/m −1 (Sr 0.15CuO) at 293 K. Maximum ZT values reach 0.76 at 873 K.
Abstract: p-type BiCuSeO, a layered oxyselenide composed of conductive (Cu2Se2)2− layers alternately stacked with insulating (Bi2O2)2+ layers, shows an enhancement of the electrical conductivity after substituting Bi3+ by Sr2+, from 470 S m−1 (BiCuSeO) to 4.8×104 S m−1 (Bi0.85Sr0.15CuSeO) at 293 K. Coupled to high Seebeck coefficients, this leads to promising values of the thermoelectric power factor that exceeds 500 μW m−1 K−2 at 873 K. Moreover, the thermal conductivity of these layered compounds is lower than 1 W m−1 K−1 at 873 K. Maximum ZT values reach 0.76 at 873 K, making this family promising for thermoelectric applications in the medium temperature range.
342 citations
TL;DR: In this paper, the authors present a model calculation, employing first-principles calculations as well as empirical data, which suggests that properly hole-doped bulk PbSe may show a Seebeck coefficient as high as $230\text{ }\ensuremath{\mu}\text{V}/ \text{K}, in a temperature regime in which the lattice thermal conductivity is rather small.
Abstract: We present a model calculation, employing first-principles calculations as well as empirical data, which suggests that properly hole-doped bulk PbSe may show a Seebeck coefficient as high as $230\text{ }\ensuremath{\mu}\text{V}/\text{K}$, in a temperature regime in which the lattice thermal conductivity is rather small. It may therefore show a figure-of-merit ZT as high as 2 for temperatures of 1000 K. Heavily doped p-type PbSe may offer better thermoelectric performance than the sister material, optimized PbTe, for high-temperature applications such as power generation.
239 citations
TL;DR: In this article, the thermal co-evaporation deposition process for n-type bismuth telluride (Bi2Te3) thin films deposited onto polyimide substrates and intended for thermoelectric applications is reported.
204 citations
TL;DR: In this article, a series of hydrochloric acid-doped polyaniline (PANI) was prepared by chemical oxidative polymerization and the effects of HCl-doping concentration on the thermoelectric properties in the temperature range of 303-423 K were discussed.
197 citations
TL;DR: In this paper, the electrical conductivity and Seebeck coefficient of a series of heavily doped regioregular poly(3-hexylthiophene) films are measured between 220 and 370 K.
Abstract: Conducting polymers have recently been suggested as thermoelectric materials for use in large-area thermogenerators. To help assessing the feasibility of this the electrical conductivity and Seebeck coefficient of a series of heavily doped regioregular poly(3-hexylthiophene) films are measured between 220 and 370 K. $p$-type chemical doping of up to 34% is accompanied by the introduction of negatively charged counterions, ${\text{PF}}_{6}^{\ensuremath{-}}$. The counterions produce a disordered environment within which the $p$-type electronic carriers move. This disorder diminishes with increasing doping as the effect of the counterions is smoothed out. Concomitantly the thermally activated electrical conductivity rises strongly while its activation energy decreases. On the other hand, the Seebeck coefficient is found to be weakly dependent on temperature and it decreases with increasing doping. When combined, these results indicate that the thermoelectric power factor reaches a broad maximum between 20% and 31% doping. These results are discussed in terms of the thermally activated hopping-type mobility of bipolarons, deduced from the absence of electron spin resonance signal in the heavily doped materials.
197 citations
TL;DR: In this paper, the authors present an overview of the challenges and practices of thermoelectric metrology on bulk materials at high temperature (300 to 1300 K) and compare the relevant measurement techniques and apparatus designs required to effectively manage uncertainty.
Abstract: We present an overview of the challenges and practices of thermoelectric metrology on bulk materials at high temperature (300 to 1300 K). The Seebeck coefficient, when combined with thermal and electrical conductivity, is an essential property measurement for evaluating the potential performance of novel thermoelectric materials. However, there is some question as to which measurement technique(s) provides the most accurate determination of the Seebeck coefficient at high temperature. This has led to the implementation of nonideal practices that have further complicated the confirmation of reported high ZT materials. To ensure meaningful interlaboratory comparison of data, thermoelectric measurements must be reliable, accurate, and consistent. This article will summarize and compare the relevant measurement techniques and apparatus designs required to effectively manage uncertainty, while also providing a reference resource of previous advances in high temperature thermoelectric metrology.
196 citations
TL;DR: In this article, the porosity effects on electron and phonon transport were modeled to predict and explain thermoelectric properties in porous nanograined materials, and the modeling results showed that the charge carriers are scattered more severely in nanoglarned materials than the macroscale porous materials, due to a higher number density of scattering sites.
Abstract: The recent achievement of the high thermoelectric figure of merit in nanograined materials is attributed to the successful optimization of the consolidation process. Despite a thermal conductivity reduction, it has been experimentally observed that the porous nanograined materials have lower thermoelectric figure of merit than their bulk counterpart due to significant reduction in the electrical conductivity. In this paper, nanoscale porosity effects on electron and phonon transport are modeled to predict and explain thermoelectricproperties in porous nanograined materials.Electron scattering at the pores is treated quantum mechanically while phonon transport is treated using a classical picture. The modeling results show that the charge carriers are scattered more severely in nanograined materials than the macroscale porous materials, due to a higher number density of scattering sites. Porous nanograined materials have enhanced Seebeck coefficient due to energy filtering effect and low thermal conductivity, which are favorable for thermoelectric applications. However, the benefit is not large enough to overcome the deficit in the electrical conductivity, so that a high sample density is necessary for nanograined SiGe.
TL;DR: In this paper, the authors propose polymer blends in which ground state hole carriers, created by doping a minor additive component, are mainly at an orbital energy set below the hole energy of the major component of the blend, leading to a regime in which hole conductivity and Seebeck coefficient may be increased in parallel.
Abstract: The Seebeck coefficient, a defining parameter for thermoelectric materials, depends on the contributions to conductivity of charge carriers at energies away from the Fermi level. Highly conductive materials tend to exhibit conductivity from carriers close to the Fermi level. In this article, we propose polymer blends in which ground state hole carriers, created by doping a minor additive component, are mainly at an orbital energy set below the hole energy of the major component of the blend. Transport, however, is expected to occur through the major component. This leads to a regime in which hole conductivity and Seebeck coefficient may be increased in parallel. While the absolute conductivity of the composite, and thus ZT, are not particularly high, this work demonstrates a route for designing thermoelectric materials in which increases in Seebeck coefficient and conductivity do not cancel each other.
TL;DR: In this paper, p-type GaSb nanostructured inclusions (5-20nm) were dispersed by an in situ method involving the introduction of metastable void-filling impurity Ga and enrichment of Sb in the synthesis procedure.
TL;DR: It is found that the solubility of Cd is less than previously reported, and CdTe precipitation occurs to create nanostructuring, which strongly suppresses the lattice thermal conductivity.
Abstract: We explored the effect of Cd substitution on the thermoelectric properties of PbTe in an effort to test a theoretical hypothesis that Cd atoms on Pb sites of the rock salt lattice can increase the ...
TL;DR: In this paper, an evacuated quartz ampoule was used to synthesize Bi 2 O 2 Se 3 and Bi O 2 O 3 by solid state reaction in a tetragonal type lattice.
TL;DR: In this article, a prototype concentration solar thermoelectric generator (CTG) and a discrete numerical model for the evaluation of the whole system are presented, which takes into account the temperature dependence of the thermiolectric material properties.
Abstract: Thermoelectric technology can be another direct way to convert solar radiation into electricity, using the Seebeck effect. Herein, a prototype concentration solar thermoelectric generator (CTG) and a discrete numerical model for the evaluation of the whole system are presented. The model takes into account the temperature dependence of the thermoelectric material properties by dividing the thermoelectric leg into finite elements and is proved to be more accurate for calculation of the conversion efficiency of the thermoelectric modules when large temperature gradients occur in the CTG system. Based on the best available properties of various bulk thermoelectric materials reported in the literature, the best possible performance of the CTG system is predicted, and the CTG system design, including the selection of the concentration ratio and the cooling method for different thermoelectric materials, are discussed in detail.
TL;DR: In this paper, the effect of K and K-Na substitution for Pb atoms in the rocksalt lattice of PbTe was investigated to test a hypothesis for development of resonant states in the valence band that may enhance the thermoelectric power.
Abstract: The effect of K and K-Na substitution for Pb atoms in the rocksalt lattice of PbTe was investigated to test a hypothesis for development of resonant states in the valence band that may enhance the thermoelectric power. We combined high-temperature Hall-effect, electrical conductivity, and thermal conductivity measurements to show that K-Na codoping do not form resonance states but can control the energy difference of the maxima of the two primary valence subbands in PbTe. This leads to an enhanced interband interaction with rising temperature and a significant rise in the thermoelectric figure of merit of p-type PbTe. The experimental data can be explained by a combination of a single- and two-band models for the valence band of PbTe depending on hole density that varies in the range of 1-15 x 10{sup 19} cm{sup -3}.
TL;DR: In this paper, a single parabolic band model was used to obtain the carrier concentration dependence of the figure of merit and an optimum carrier concentration near 5 × 1019 cm−3 was predicted.
Abstract: β-Zn4Sb3 is a promising thermoelectric material due to the abundance of zinc and antimony and reports of high efficiency in bulk samples. This work establishes the high temperature properties of β-Zn4Sb3 across the phase stability window. By controlling the stoichiometry, the Hall carrier concentration can be tuned from 6–9 × 1019 cm−3 without requiring extrinsic dopants. The trend in Seebeck coefficient on carrier concentration is rationalized with a single, parabolic band model. Extremely low lattice thermal conductivity (0.4–0.6 W m−1 K−1) coupled with a moderate effective mass (1.2 me) and mobility leads to a large figure of merit (zT of 0.8 by 550 K). The single parabolic band model is used to obtain the carrier concentration dependence of the figure of merit and an optimum carrier concentration near 5 × 1019 cm−3 is predicted.
TL;DR: In this paper, the authors investigated the figure of merit of a quantum dot (QD) in the Coulomb blockade regime, and they found that it is more likely to find a high efficient thermoelectric QDs with large Coulomb interaction.
Abstract: We investigate the figure of merit of a quantum dot (QD) in the Coulomb blockade regime. It is found that the figure of merit $ZT$ may be quite high if only single-energy level in the QD is considered. On the other hand, with two or multienergy levels in the QD and without the Coulomb interaction, the $ZT$ is strongly suppressed by the bipolar effect due to small level spacing. However, in the presence of the Coulomb interaction, the effective level spacing is enlarged and the bipolar effect is weakened, resulting in $ZT$ to be considerably high. Thus, it is more likely to find a high efficient thermoelectric QDs with large Coulomb interaction. By using the parameters for a typical QD, the $ZT$ can reach over 5.
TL;DR: In this paper, a series of Fe, Mn, and Cu doped Ca3Co4O9 was investigated and the results indicated that Fe/Mn substitutes for Co in CoO2 layers whereas Cu substitutes for CO in Ca2CoO3 layers.
Abstract: We report the strongly correlated, electrical transport, magnetic, and thermoelectric properties of a series of Fe, Mn, and Cu doped Ca3Co4O9. The results indicate that Fe/Mn substitutes for Co in CoO2 layers whereas Cu substitutes for Co in Ca2CoO3 layers. Because of the different doping sites, the electronic correlations increase remarkably in Fe and Mn doped series while remaining unchanged in Cu doped series. Correspondingly, the transport mechanism, magnetic properties, and some characteristic parameters along with transition temperatures all exhibit two distinct evolutions for Fe/Mn doping and Cu doping. The thermoelectric characteristics are improved in each series. Nevertheless, the improvement of thermoelectric performance is most significant in Fe doped samples due to the unexpected changes in thermopower and resistivity. The unusual thermopower behavior can be well described by the variations of electronic correlation. Possible approaches for further improvement of the thermoelectric performanc...
TL;DR: In this article, the authors measured the thermal conductivities of multilayer carbon nanotube (MWCNT) arrays up to 6mm high with an array density of 0.06 grams per cm−3.
TL;DR: In this paper, a substitutional series of Heusler compounds was synthesized and investigated with respect to their electronic structure and transport properties, and the results showed the possibility to create $n$-type and low $p$ -type thermoelectrics within one Heussler compound.
Abstract: The substitutional series of Heusler compounds ${\text{NiTi}}_{1\ensuremath{-}x}{M}_{x}\text{Sn}$ (where $M=\text{Sc},\text{V}$ and $0lx\ensuremath{\le}0.2$) were synthesized and investigated with respect to their electronic structure and transport properties. The results show the possibility to create $n$-type and $p$-type thermoelectrics within one Heusler compound. The electronic structure and transport properties were calculated by all-electron ab initio methods and compared to the measurements. Hard x-ray photoelectron spectroscopy was carried out and the results are compared to the calculated electronic structure. Pure NiTiSn exhibits massive ``in gap'' states containing about 0.1 electrons per cell. The comparison of calculations, x-ray diffraction, and photoemission reveals that Ti atoms swapped into the vacant site are responsible for these states. The carrier concentration and temperature dependence of electrical conductivity, Seebeck coefficient, and thermal conductivity were investigated in the range from 10 to 300 K. The experimentally determined electronic structure and transport measurements agree well with the calculations. The sign of the Seebeck coefficient changes from negative for V to positive for Sc substitution. The high $n$-type and low $p$-type power factors are explained by differences in the chemical-disorder scattering-induced electric resistivity. Major differences appear because $p$-type doping (Sc) creates holes in the triply degenerate valence band at $\ensuremath{\Gamma}$ whereas $n$-type doping (V) fills electrons in the single conduction band above the indirect gap at $X$ what is typical for all semiconducting transition-metal-based Heusler compounds with $C{1}_{b}$ structure.
TL;DR: In this paper, a series of Fe, Mn, and Cu doped Ca(3)Co(4)O(9+delta) samples were fabricated by cold high-pressure compacting technique.
Abstract: A series of Fe, Mn, and Cu doped Ca(3)Co(4)O(9+delta) samples, Ca(3)(Co,M)(4)O(9+delta) (M=Fe, Mn, and Cu), were fabricated by cold high-pressure compacting technique. Their thermoelectric properties were investigated from room temperature up to 1000 K. The cold high-pressure compacting method is advantageous to increasing density and texture, in favor of the improvement of thermoelectric performance. The electrical transport measurements indicate that Fe/Mn substitutes for Co mainly in [CoO(2)] layers whereas the substitution of Cu for Co takes place in [Ca(2)CoO(3)] layers. The thermoelectric properties as well as electronic correlations depend not only on the substitution ion but also the Co site that is replaced. Thermopower can be well calculated by the carrier effective mass according to Boltzmann transport model, indicating that the electronic correlation plays a crucial role in the unusual thermoelectric characteristics of this system. From the changes in thermopower, resistivity, and thermal conductivity, thermoelectric performance of Ca(3)Co(4)O(9+delta) is efficiently improved by these transition metals doping. Fe doped samples possess the highest ZT values. Combining cold high-pressure technique, ZT of Ca(3)Co(3.9)Fe(0.1)O(9+delta) can reach similar to 0.4 at 1000 K, which is quite large among ceramic oxides, suggesting that Fe doped Ca(3)Co(4)O(9+delta) could be a promising candidate for thermoelectric applications at elevated temperatures.
TL;DR: In this paper, a mixture of Pr and Nd was used as a new filler in ternary skutterudites (Fe 1− x Co 2 Sb 12 and Fe 1−x Ni x ) 4 sb 12, in order to improve the thermoelectric properties via efficient phonon scattering.
TL;DR: In this article, a microwave-assisted method using SbCl3, Na2TeO3 and hydrazine hydrate in ethylene glycol at 200 °C for 15 min, and the reaction mechanism was proposed.
Abstract: Sb2Te3 single-crystalline nanosheets having edge lengths of 300–500 nm and thicknesses of 50–70 nm were rapidly synthesized by a microwave-assisted method using SbCl3, Na2TeO3 and hydrazine hydrate in ethylene glycol at 200 °C for 15 min, and the reaction mechanism was proposed. The bulk sample of Sb2Te3 nanosheets was prepared by spark plasma sintering (SPS), and it still consisted of Sb2Te3 nanosheets after SPS and thermoelectric property measurements. High electrical conductivity σ (2.49 × 104 Ω−1 m−1), high Seebeck coefficient S (210 μV K−1) and low thermal conductivity κ (0.76 W m−1 K−1) at 420 K were achieved. The ZT value was reported for the first time for the Sb2Te3 sintered bulk sample prepared from nanosheet powder, and a relatively high ZT of 0.58 at 420 K was obtained. It is very difficult to achieve high electrical conductivity σ without obvious growth of nanocrystals after sintering, and herein we have made a successful attempt.
TL;DR: In this paper, the Seebeck coefficient and the currentvoltage (I-V) characteristics of a molecular junction were measured to determine the identity and the effective energetic separation of the molecular orbital closest to the electrodes' Fermi level.
Abstract: We report an experimental technique that concurrently measures the Seebeck coefficient and the current-voltage (I-V) characteristics of a molecular junction to determine the identity and the effective energetic separation of the molecular orbital closest to the electrodes’ Fermi level. Junctions created by contacting a gold-coated atomic force microscope tip with a monolayer of molecules assembled on a gold substrate were found to have a Seebeck coefficient of (+16.9±1.4) μV/K. This positive value unambiguously shows that the highest occupied molecular orbital (HOMO) dominates charge transport. Further, by analyzing the (I-V) characteristics, the HOMO level is estimated to be ∼0.69 eV with respect to the Fermi level.
TL;DR: In this article, band structures for ZrNiSn with Zr/Sn antisite defects are calculated with ab initio methods, and the maximum ZT is 0.64 at 800 K.
Abstract: Band structures for ZrNiSn with Zr/Sn antisite defects are calculated with ab initio methods. Antisite defects shrink the band gap and enhance the density of states slope near the Fermi level, which are favorable to electrical transport properties for intrinsic semiconductors. The degree of Zr/Sn antisite defects are controlled by annealing time experimentally, and measurements show low electrical resistivity and high Seebeck coefficient for unannealed ZrNiSn, which benefits from the modified electronic structure caused by antisite defects. The maximum ZT is 0.64 at 800 K for unannealed ZrNiSn, which is the highest value for ZrNiSn systems without exterior doping.
TL;DR: In this paper, the thermoelectric performance of thin films fabricated from two commercially available, highly conductive polymer formulations based on poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was investigated.
Abstract: The thermoelectric performance of thin films fabricated from two commercially available, highly conductive polymer formulations based on poly (3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was investigated. In order to enhance the electrical conductivity, the high-boiling solvent dimethyl sulfoxide (DMSO) was added. By changing the content of DMSO the electrical conductivity was increased by a factor of two without changing the Seebeck coefficient or the thermal conductivity. We achieved ZT = 9.2 × 10−3 at room temperature upon the addition of 5 vol.% DMSO to the PEDOT:PSS formulation.
TL;DR: In this paper, the magnetic properties of single crystal antimony telluride (Sb2Te3) nanowires with diameters in the range of 20−100 nm were investigated.
Abstract: We report measurements of electronic, thermoelectric, and galvanomagnetic properties of individual single crystal antimony telluride (Sb2Te3) nanowires with diameters in the range of 20−100 nm. Temperature-dependent resistivity and thermoelectric power (TEP) measurements indicate hole dominant diffusive thermoelectric generation with an enhancement of the TEP for smaller diameter wires up to 110 μV/K at T = 300 K. We measure the magnetoresistance in magnetic fields both parallel and perpendicular to the nanowire [110] axis, where strong anisotropic positive magnetoresistance behavior was observed.
TL;DR: It is found that the intrinsic magnetic anisotropy of the single-molecule magnet can lead to gate-voltage-dependent oscillations of charge thermopower and a large violation of the Wiedeman-Franz law.
Abstract: We study the spin-dependent thermoelectric transport through a single-molecule-magnet junction in the sequential tunneling regime. It is found that the intrinsic magnetic anisotropy of the single-molecule magnet can lead to gate-voltage-dependent oscillations of charge thermopower and a large violation of the Wiedeman-Franz law. More interestingly, the spin-Seebeck coefficient is shown to be greater than the charge-Seebeck coefficient, and a pure spin thermopower or/and a pure spin current can be obtained by tuning only the gate voltage. It needs neither an external magnetic field or irradiation of circularly polarized light on the molecule nor ferromagnetic leads to realize these interesting effects, indicating the powerful prospect of single-molecule-magnet applications in spintronic devices.