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Bi2Te3基化合物因其优异的电输运性能和较低热导率在近室温热电材料中备受关注，研究表明固溶和掺杂是优化Bi2Te3基材料性能的有效途径。目前，硒(Se)作为掺杂剂的n型Bi2Te3-xSex基材料已有研究报道，但Te位Se直接掺杂对其缺陷结构、微观组织及能带间隙的调控机理尚未得到系统研究。本文系统研究了Te位Se直接掺杂对三元n型Bi2Te3-xSex基化合物的缺陷结构、微结构及带隙的调控行为及其对热电输运性能的影响规律。Se掺杂Te位点形成n型施主缺陷SeTe· ，抑制Bi'Te反位缺陷并促使Bi回归本征位，同时产生Te间隙原子(Tei×)和空位缺陷(VTe··)，优化载流子浓度和迁移率，有效提高材料的电性能。此外，过饱和Te以间隙原子形式扩散析出形成第二相。Se掺杂通过点缺陷引发的质量与应变场波动增强声子散射，显著降低晶格热导率。随x增加，样品带隙增加，本征激发引诱的双极效应所导致的性能恶化被显著抑制。结果，Bi2Te2.7Se0.3样品在300-500 K温区获得最大平均zT值(zTave)为0.73。退火后因样品微结构优化，Bi2Te2.4Se0.6样品功率因子提高，热导率下降，420 K时获得最大zT值为0.81，300-500 K温区zTave为0.76。这表明Se直接掺杂可以拓宽最佳zT值对应温区，退火工艺可进一步优化其热电性能。该研究为开发宽温区高性能近室温热电材料提供了研究思路。
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关键词:
- Bi2Te3基热电材料 /
- Se掺杂 /
- 宽温区 /
- 热电性能
Bi2Te3-based compounds have garnered significant attention for near-room-temperature thermoelectric applications due to their excellent electrical transport properties and low thermal conductivity. Solid solutions and doping are effective methods for optimizing the performance of Bi2Te3-based materials. Currently, n-type Bi2Te3-xSex materials using selenium (Se) as a dopant have been reported. However, the regulatory mechanisms of direct Se doping at Te sites on their defect structure, microstructure, and bandgap have not yet been systematically investigated. This work systematically investigates the regulatory behavior of direct Se doping at Te sites on the defect structure, microstructure, and bandgap of ternary n-type Bi2Te3-xSex compounds, and its impact on thermoelectric transport properties. Se substitution at Te sites forms n-type donor defects SeTe·, suppresses the formation of Bi'Te antisite defects, and facilitates the return of Bi atoms to their intrinsic lattice sites. Concurrently, it introduces Te interstitial atoms (Tei×) and Te vacancies (VTe··), optimizing both carrier concentration and mobility, thereby effectively enhancing the electrical performance. Furthermore, supersaturated Te diffuses out as interstitial atoms and precipitates to form secondary phases. Se doping enhances phonon scattering via mass and strain field fluctuations induced by point defects, leading to a significant reduction in lattice thermal conductivity. As x increases, the bandgap of the samples is widened, resulting in significant suppression of the performance degradation caused by the intrinsic-excitation-induced bipolar effect. Consequently, the Bi2Te2.7Se0.3 sample achieved amaximum average zT (zTave) value of 0.73 within the 300-500 K temperature range. After annealing, the optimization of the sample's microstructure led to an enhanced power factor and reduced thermal conductivity in the Bi2Te2.4Se0.6 sample, achieving a maximum zT value of 0.81 at 420 K and and a zTave value of 0.76 in the 300-500 K temperature range. These results demonstrate that direct Se doping at Te sites can broaden the temperature range corresponding to the optimal zT values, and that the annealing process can further optimize the thermoelectric performance. This study provides significant insights for developing high-performance near-room-temperature thermoelectric materials applicable to broad operating temperatures. -
[1] Bell L E 2008 Science 321 1457
[2] Wang H, Pan Z Y 2023 Mater Lab 2 220053
[3] Lu W B, Luo W, Fan Y C, Ding Q, Jiang W 2024 Adv Ceram 45 177(in Chinese)[鲁文 彬,罗维,范宇驰,丁奇,江莞2024现代技术陶瓷45 177]
[4] Liu Z Y, Wang Y G, Yang T, Ma Z J, Zhang H Y, Li H L, Xia A L 2023 J Adv Ceram 12 539
[5] Liu Z Y, Zhu J L, Tong X, Niu S, Zhao W Y 2020 J Adv Ceram 9 647
[6] Zhou H Y, Liu H, Qian G P, Yu H N, Gong X B, Li X B, Zheng J L. 2022 Micromachines 13 233
[7] Wang G, Cagin T 2007 Phys Rev B 76 075201
[8] Li L, Wei P, Yang M J, Zhu W T, Nie X L, Zhao W Y, Zhang Q J 2023 Sci China Mater 66 3651
[9] Lou L, Yang J, Zhu Y, Liang H, Zhang Y, Feng J, He J, Ge Z, Zhao L 2022 Adv Sci 9 2203250
[10] Guo X, Zhang C, Liu Z, He P, Szczęsny R, Jin F, Liu W, Gregory D 2021 ACS Appl. Mater. Interfaces 13 13400
[11] An J, Han M, Kim S 2019 J Solid State Chem 270 407
[12] Guan X, Liu Z, Ma N, Li Z, Liu J, Zhang H, Li H, Ba Q, Ma J, Jin C, Xia A 2025 Acta Metall Sin-Engl 38 849
[13] Li R Y, Luo T T, Li M, Chen S, Yan Y G, Wu J S, Su X L, Zhang Q J, Tang X F 2024 Acta Phys Sin 73 097101(in Chinese)[李睿英,罗婷婷,李貌,陈硕,鄢永高,吴劲松,苏 贤礼,张清杰,唐新峰2024物理学报73 097101]
[14] Zhu B, Wang W, Cui J, He J 2021 Small 17 2101328
[15] Wu F, He Q, Tang M, Song H 2018 Int J Mod Phys B 32 1850123
[16] Li D, Qin X Y, Dou Y C, Li X Y, Sun R R, Wang Q Q, Li L L, Xin H X, Wang N, Wang N N, Song C J, Liu Y F, Zhang J 2012 Scripta Mater 67 161
[17] Pan Y, Wei T R, Wu C F, Li J F 2015 J Mater Chem C 3 10583
[18] Li D, Qin X Y, Zhang J, Song C J, Liu Y, Wang L, Xin H, Wang Z 2015 RSC Adv 5 43717
[19] Zhang Q, Xu L, Wang L, Jiang W 2014 J Inorg Mater 29 1139(in Chinese)[张骐昊, 徐磊磊,王连军,江莞2014无机材料学报29 1139]
[20] Vinoth S, Vinoth S, Roy V A L, Thilakan P 2024 J Cryst Growth 625 127442
[21] Kawajiri Y, Tanusilp S-A, KumagaiM, IshimaruM, Ohishi Y, Tanaka J, Kurosaki K 2021 ACS Appl. Mater. Interfaces 4 11819
[22] Su D, Cheng J, Li S, Zhang S, Lyu T, Zhang C, Li J, Liu F, Hu L 2023 J Mater Sci Technol 138 50
[23] Puneet P, Podila R, Karakaya M, Zhu S, He J, Tritt T, Dresselhaus M, Rao A 2013 Sci Rep 2013 3 1
[24] Sharma K, Kumar A, Goyal N, Lal M 2013 AIP Conf Proc 1536 603
[25] Kim C, Kim C E, Baek J Y, Kim D, Kim J, Ahn J, Hyeon Lopez D, Kim T, Kim H 2016 Ind Eng Chem Res 55 5623
[26] Zhang Q, Ai X, Wang L, Chang Y, Luo W, Jiang W, Chen L 2015 Adv Function Mater 25 966
[27] Ren Z, Taskin A A, Sasaki S, Segawa K, Ando Y 2012 Phys. Rev. B 85 1903
[28] Zhu T J, Hu L P, Zhao X B, He J 2016 Adv Sci 3 1600004
[29] Li Z, Xiao C, Zhu H, Xie Y 2016 J. Am. Chem. Soc 138 14810
[30] Li Z, Deng T T, Qiu P F, Ming C, Gao Z Q, Chen L D, Shi X 2025 Nat Commun 16 5190
[31] Zhao L D, Zhang B P, Liu W S, Zhang H, Li J 2009 J Alloy Compd 467 91
[32] Wang S, Tan G, Xie W, Gang Z, Han L, Yang J, Tang X 2012 J Mater Chem A 22 20943
[33] Hu L, Guo Y, Li J, Ao W, Liu F 2018 Mater Res Bull 99 377
[34] Scanlon D O, King P D C, Singh R P, de la Torre A, Walker S M, Balakrishnan G, Baumberger F, Catlow C R A 2012 Adv Mater 24 2154
[35] Horák J, Stary Z, Lošt'ák P, Pancí J 1990 J Phys Chem Solids 51 1353
[36] Zhao A Q, Liu H, Sun T, Lang Y D, Chen C C, Pan L, Wang Y F 2024 J Alloy Compd 982 173806
[37] Fan C, Sakamoto K, Krüger P 2024 Appl Sur Sci 643 158699
[38] Snyder G J, Toberer E S 2008 Nat Mater 7 105
[39] Ma S F, Li C C, Cui W J, Sang X H, Wei P, Zhu W T, Nie X L, Sun F H, Zhao W Y, Zhang Q J 2021 Sci China Mater 64 2835
[40] Cutler M, Leavy J F, Fitzpatrick R L 1964 Phys Rev 133 1143
[41] Kim H S, Gibbs Z M, Tang Y, Wang H, Snyder G 2015 Appl Phys Lett 3 041506
[42] Zhu J L, Liu Z Y, Tong X, Xia A L, Xu D, Lei Y, Yu J, Tang D G, Ruan X F, Zhao W Y 2021 ACS Appl. Mater. Interfaces 13 23894
[43] Callaway J, Von Baeyer H. C 1960 Phys Rev 120 1149
[44] Nolas G S, Sharp J, Goldsmid J. 2013 Springer Science&Business Media p15
[45] Sharma V, Singh S P, Mudahar G S, Kulwant S 2012 New J Glass Ceram 2 128
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