SnO的歧化反应对SnTe热电性能的优化
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摘要
PbTe基化合物是一种热电性能优良的中温区热电材料,但铅的毒性限制了其广泛应用,因此类似化合物SnTe引起了人们关注。但SnTe的载流子浓度较高和晶格热导率较大使其ZT值较低。本研究利用SnO歧化反应对SnTe热电性能实现了协同调控。热压烧结过程中SnO在500℃左右发生歧化反应生成Sn单质和单分散的SnO2颗粒,Sn单质作为自掺杂可以填充SnTe中的Sn空位,导致载流子浓度降低:相比于SnTe基体,SnTe-6mol%SnO样品在600℃下的电阻率从6.5增大到10.5???m, Seebeck系数从105增大到146?V?K?1。同时,原位反应生成的SnO2第二相单分散于晶界处,多尺度散射声子传播而降低晶格热导率,SnTe-6mol%SnO样品晶格热导率在600℃下仅为0.6 W?m?1?K?1,相比于基体下降了33%左右,从而使SnTe体系的热电性能得到明显提高。最终,当SnO加入量为6mol%时,样品在600℃下的ZT值～1,相比于基体提升了一倍左右。
PbTe-based compositions are considered as excellent thermoelectric materials for the mid-temperature.However, the toxicity of lead limits its wide application. SnTe compounds, an analogue of PbTe, has attracted much attention. However, its ultrahigh carrier concentration and the large lattice thermal conductivity leads to a low ZT value of SnTe. In this work, the thermoelectric performance of SnTe is synergistically enhanced by introduction of Sn and SnO2 from the disproportionation of SnO in the process of the hot press sintering. On the one hand, Sn can compensate the Sn vacancies and decrease the carrier concentration of SnTe, leading to a simultaneous enhancement on resistivity and the Seebeck coefficient. For instance, compared with the pristine SnTe, resistivity and the Seebeck coefficient increases from 6.5 ???m to 10.5 ???m and from 105 ?V?K–1 to 146 ?V?K–1, respectively, for the sample of SnTe-6 mol% SnO at 873 K. On the other hand, in-situ generated SnO2 nanoparticles are dispersedly distributed on the grain boundaries, leading to the multiscale phonon scattering and the reduced lattice thermal conductivity. The minimum lattice thermal conductivity value is 0.6 W?m–1?K–1 for the sample SnTe-6 mol% SnO at 873 K, which is ～33%reduction compared with that of the pristine SnTe. As a result, the maximum ZT value of 0.96(～100% enhancement,compared with that of the pristine SnTe) at 873 K is achieved for the sample SnTe-6 mol% SnO.
PbTe-based compositions are considered as excellent thermoelectric materials for the mid-temperature.However, the toxicity of lead limits its wide application. SnTe compounds, an analogue of PbTe, has attracted much attention. However, its ultrahigh carrier concentration and the large lattice thermal conductivity leads to a low ZT value of SnTe. In this work, the thermoelectric performance of SnTe is synergistically enhanced by introduction of Sn and SnO2 from the disproportionation of SnO in the process of the hot press sintering. On the one hand, Sn can compensate the Sn vacancies and decrease the carrier concentration of SnTe, leading to a simultaneous enhancement on resistivity and the Seebeck coefficient. For instance, compared with the pristine SnTe, resistivity and the Seebeck coefficient increases from 6.5 ???m to 10.5 ???m and from 105 ?V?K–1 to 146 ?V?K–1, respectively, for the sample of SnTe-6 mol% SnO at 873 K. On the other hand, in-situ generated SnO2 nanoparticles are dispersedly distributed on the grain boundaries, leading to the multiscale phonon scattering and the reduced lattice thermal conductivity. The minimum lattice thermal conductivity value is 0.6 W?m–1?K–1 for the sample SnTe-6 mol% SnO at 873 K, which is ～33%reduction compared with that of the pristine SnTe. As a result, the maximum ZT value of 0.96(～100% enhancement,compared with that of the pristine SnTe) at 873 K is achieved for the sample SnTe-6 mol% SnO.
引文
[1]朱铁军,赵新兵.β-Fe Si2热电材料的性能优化及测试方法.材料科学与工程, 1999(4):55–59.
[2]ZHU T J, CAO Y Q, ZHANG Q, et al. Bulk nanostructured thermoelectric materials:preparation, structure and properties. Journal of Electronic Materials, 2010, 39(9):1990–1995.
[3]YU C, ZHU T J, SHI R Z, et al. High-performance half-heusler thermoelectric materials Hf1-xZrxNiSn1-ySby prepared by levitation melting and spark plasma sintering. Acta Materialia, 2009, 57(9):2757–2764.
[4]XIE H H, WANG H, PEI Y Z, et al. Beneficial contribution of alloydisordertoelectronandphonontransportinhalf-Heusler thermoelectricmaterials.AdvancedFunctionalMaterials,2013,23(41):5123–5130.
[5]CHEN Z W, ZHANG X Y, PEI Y Z, et al. Manipulation of phonon transportinthermoelectrics.AdvancedMaterials,2018,30(17):1705617–1–12.
[6]MOSHWAN R, YANG L, ZOU J, et al. Eco-friendly SnTe thermoelectricmaterials:progressandfuturechallenges.Advanced Functional Materials, 2017, 27(43):1703278–1–18.
[7]AL RAHAL AL ORABI R, MECHOLSKY N A, HWANG J, et al.Band degeneracy, low thermal conductivity, and high thermoelectric figure of merit in SnTe-CaTe alloys. Chemistry of Materials,2016, 28(1):376–384.
[8]TAN X F, LIU G Q, XU J T, et al. Thermoelectric properties of In-Hgco-dopinginSnTe:energybandengineering.Journalof Materiomics, 2018, 4(1):62–67.
[9]JIANG Q H, YANG J Y, LIU Y, et al. Microstructure tailoring in nanostructured thermoelectric materials. Journal of Advanced Dielectrics, 2016, 6(1):1630002–1–16.
[10]BISWAS K, HE J Q, WANG G Y, et al. High thermoelectric figure of merit in nanostructured p-type PbTe-MTe(M=Ca, Ba). Energy&Environmental Science, 2011, 4(11):4675–4684.
[11]HERMAN F, KORTUM R, ORTENBURGER I, et al. Relativistic bandstructureofGeTe,SnTe,PbTe,PbSe,andPbS.Journalde Physique Colloques, 1968, 29(C4):C4–62–C64–77.
[12]BREBRICKRF.Deviationsfromstoichiometryandelectrical propertiesinSnTe.JournalofPhysicsandChemistryofSolids,1963, 24(1):27–36.
[13]BREBRICK R F, STRAUSS A J. Anomalous thermoelectric power as evidence for two-valence bands in SnTe. Physical Review, 1963,131(1):104–110.
[14]CROCKER A J, ROGERS L M. Interpretation of the Hall coefficient,electricalresistivityandseebeckcoefficientofp-typelead telluride. British Journal of Applied Physics, 1967, 18(5):563.
[15]VEDENEEV V P, KRIVORUCHKO S P, SABO E P. Tin telluride based thermoelectrical alloys. Semiconductors, 1998, 32(3):241–244.
[16]ZHAO L D, ZHANG X, WU H J, et al. Enhanced thermoelectric properties in the counter-doped SnTe systemwith strained endotaxialSrTe.JournaloftheAmericanChemicalSociety,2016,138(7):2366–2373.
[17]TAN G J,ZHAO LD, SHI F Y,et al. High thermoelectric performanceofp-typeSnTeviaasynergisticbandengineeringand nanostructuring approach. Journal of the American Chemical Society, 2014, 136(19):7006–7017.
[18]PEI Y Z, ZHENG L L, LI W, et al. Interstitial point defect scattering contributing to high thermoelectric performance in SnTe. Advanced Electronic Materials, 2016, 2(6):1600019.
[19]ZHOU Z W, YANG J Y, JIANG Q H, et al. Multiple effects of Bi doping in enhancing the thermoelectric properties of SnTe. Journal of Materials Chemistry A, 2016, 4(34):13171–13175.
[20]ZHENG L L, LI W, LIN S Q, et al. Interstitial defects improving thermoelectric SnTe in addition to band convergence. ACS Energy Letters, 2017, 2(3):563–568.
[21]陶东平,杨显万.氧化亚锡歧化还原动力学和二氧化锡还原机理.中国有色金属学报, 1998(1):129–133.
[22]PEI Y Z, SHI X Y, LALONDE A, et al. Convergence of electronic bandsforhighperformancebulkthermoelectrics.Nature,2011,473(7345):66.
[23]LITTLEWOOD P B, MIHAILA B, SCHULZE R K,et al. Band structure of SnTe studied by photoemission spectroscopy. Physical Review Letters, 2010, 105(8):086404–1–4.
[24]LIU W S, ZHANG Q Y, LAN Y C, et al. Thermoelectric property studies on Cu-doped n-type CuxBi2Te2.7Se0.3 nanocomposites. Advanced Energy Materials, 2011, 1(4):577–587.
[25]TAN G J, SHI F Y, HAO S H, et al. Codoping in SnTe:enhancement of thermoelectric performance through synergy of resonance levels and band convergence. Journal of the American Chemical Society, 2015, 137(15):5100–5112.
[26]ZHANG Q, LIAO B L, LAN Y C, et al. High thermoelectric performance by resonant dopant indium in nanostructured SnTe. ProceedingsoftheNationalAcademyofSciences,2013,110(33):13261–13266.
[2]ZHU T J, CAO Y Q, ZHANG Q, et al. Bulk nanostructured thermoelectric materials:preparation, structure and properties. Journal of Electronic Materials, 2010, 39(9):1990–1995.
[3]YU C, ZHU T J, SHI R Z, et al. High-performance half-heusler thermoelectric materials Hf1-xZrxNiSn1-ySby prepared by levitation melting and spark plasma sintering. Acta Materialia, 2009, 57(9):2757–2764.
[4]XIE H H, WANG H, PEI Y Z, et al. Beneficial contribution of alloydisordertoelectronandphonontransportinhalf-Heusler thermoelectricmaterials.AdvancedFunctionalMaterials,2013,23(41):5123–5130.
[5]CHEN Z W, ZHANG X Y, PEI Y Z, et al. Manipulation of phonon transportinthermoelectrics.AdvancedMaterials,2018,30(17):1705617–1–12.
[6]MOSHWAN R, YANG L, ZOU J, et al. Eco-friendly SnTe thermoelectricmaterials:progressandfuturechallenges.Advanced Functional Materials, 2017, 27(43):1703278–1–18.
[7]AL RAHAL AL ORABI R, MECHOLSKY N A, HWANG J, et al.Band degeneracy, low thermal conductivity, and high thermoelectric figure of merit in SnTe-CaTe alloys. Chemistry of Materials,2016, 28(1):376–384.
[8]TAN X F, LIU G Q, XU J T, et al. Thermoelectric properties of In-Hgco-dopinginSnTe:energybandengineering.Journalof Materiomics, 2018, 4(1):62–67.
[9]JIANG Q H, YANG J Y, LIU Y, et al. Microstructure tailoring in nanostructured thermoelectric materials. Journal of Advanced Dielectrics, 2016, 6(1):1630002–1–16.
[10]BISWAS K, HE J Q, WANG G Y, et al. High thermoelectric figure of merit in nanostructured p-type PbTe-MTe(M=Ca, Ba). Energy&Environmental Science, 2011, 4(11):4675–4684.
[11]HERMAN F, KORTUM R, ORTENBURGER I, et al. Relativistic bandstructureofGeTe,SnTe,PbTe,PbSe,andPbS.Journalde Physique Colloques, 1968, 29(C4):C4–62–C64–77.
[12]BREBRICKRF.Deviationsfromstoichiometryandelectrical propertiesinSnTe.JournalofPhysicsandChemistryofSolids,1963, 24(1):27–36.
[13]BREBRICK R F, STRAUSS A J. Anomalous thermoelectric power as evidence for two-valence bands in SnTe. Physical Review, 1963,131(1):104–110.
[14]CROCKER A J, ROGERS L M. Interpretation of the Hall coefficient,electricalresistivityandseebeckcoefficientofp-typelead telluride. British Journal of Applied Physics, 1967, 18(5):563.
[15]VEDENEEV V P, KRIVORUCHKO S P, SABO E P. Tin telluride based thermoelectrical alloys. Semiconductors, 1998, 32(3):241–244.
[16]ZHAO L D, ZHANG X, WU H J, et al. Enhanced thermoelectric properties in the counter-doped SnTe systemwith strained endotaxialSrTe.JournaloftheAmericanChemicalSociety,2016,138(7):2366–2373.
[17]TAN G J,ZHAO LD, SHI F Y,et al. High thermoelectric performanceofp-typeSnTeviaasynergisticbandengineeringand nanostructuring approach. Journal of the American Chemical Society, 2014, 136(19):7006–7017.
[18]PEI Y Z, ZHENG L L, LI W, et al. Interstitial point defect scattering contributing to high thermoelectric performance in SnTe. Advanced Electronic Materials, 2016, 2(6):1600019.
[19]ZHOU Z W, YANG J Y, JIANG Q H, et al. Multiple effects of Bi doping in enhancing the thermoelectric properties of SnTe. Journal of Materials Chemistry A, 2016, 4(34):13171–13175.
[20]ZHENG L L, LI W, LIN S Q, et al. Interstitial defects improving thermoelectric SnTe in addition to band convergence. ACS Energy Letters, 2017, 2(3):563–568.
[21]陶东平,杨显万.氧化亚锡歧化还原动力学和二氧化锡还原机理.中国有色金属学报, 1998(1):129–133.
[22]PEI Y Z, SHI X Y, LALONDE A, et al. Convergence of electronic bandsforhighperformancebulkthermoelectrics.Nature,2011,473(7345):66.
[23]LITTLEWOOD P B, MIHAILA B, SCHULZE R K,et al. Band structure of SnTe studied by photoemission spectroscopy. Physical Review Letters, 2010, 105(8):086404–1–4.
[24]LIU W S, ZHANG Q Y, LAN Y C, et al. Thermoelectric property studies on Cu-doped n-type CuxBi2Te2.7Se0.3 nanocomposites. Advanced Energy Materials, 2011, 1(4):577–587.
[25]TAN G J, SHI F Y, HAO S H, et al. Codoping in SnTe:enhancement of thermoelectric performance through synergy of resonance levels and band convergence. Journal of the American Chemical Society, 2015, 137(15):5100–5112.
[26]ZHANG Q, LIAO B L, LAN Y C, et al. High thermoelectric performance by resonant dopant indium in nanostructured SnTe. ProceedingsoftheNationalAcademyofSciences,2013,110(33):13261–13266.