熱電發電技術為當今備受矚目的綠能相關發展技術之一，熱電材料本身能進行熱能和電能的可逆轉換，一般在工廠、汽車廢熱回收和致冷元件都能見其應用。本實驗主要研究之材料系統為碲化鉍系化合物，其在室溫範圍下擁有良好的熱電優值，且已成功運用在一些熱電發電元件與致冷元件。若能有效提升其熱電特性，將可進一步增加熱電發電系統的轉換效率，達到節能減碳的目標。本研究係以中國鋼體股份有限公司所提供的碲化鉍系化合物作為研究基材，各別將銀原子與銅原子以不同方式摻雜到熱電材料中，並探討以區域熔煉(zone melting)晶棒、冷壓(cold press)和熱壓(hot press)三種製程方式所製備材料之微結構與熱電傳輸性質。實驗結果發現，區域熔煉法製備的晶棒和手磨粉末冷壓試片具有顯著的晶體優選方向性，然而球磨粉末冷壓試片及熱壓試片則無明顯晶體優選方向。基於此晶體結構方向性上的差異，這些由不同方法所製備試片的電性量測結果亦呈現非均向性。最後，透過不同方式分別將銀原子與銅原子摻雜到碲化鉍系材料中，再以自製掃描式Seebeck電壓量測機台進行量測，發現在材料可觀察到一較不尋常的熱電效應，顯示在特定製程條件下有機會提升材料的熱電特性。本研究將比較不同製程所製備碲化鉍系化合物中銀原子與銅原子的擴散特性，及其對材料熱電傳輸性質的影響。

Thermoelectric power generation that converts thermal energy into electrical energy has been considered to be a promising green technology. Bismuth telluride based compounds have reasonably high thermoelectric figure-of-merit at room temperature regime. They have been widely employed in the applications of waste-heat recovery and thermoelectric refrigeration. If the thermoelectric properties of bismuth telluride compounds can be improved further, it would possible to increase the conversion efficiency of thermoelectric devices and contribute to the reduction of CO2 emission. In the study, bismuth telluride based raw materials are provided by the China Steel Corporation. Three different processing methods including zone-melting, cold press and hot press were used to prepare the Bi-Sb-Te compounds. The microstructure and thermoelectric transport properties of these materials with different doping processes are investigated. The samples prepared by zone melting and cold-press with hand-crushed powders have shown preferred crystallographic texture, while those by hot-press and cold press with ball-milled powders have no preferred texture. The anisotropic crystallographic texture leads to anisotropic transport properties. In addition, the samples with special Ag and Cu doping profiles have shown an unusual thermoelectric effect measured by a home-made scanning Seebeck system. The results suggest that it is possible to change the transport properties of Bi-Sb-Te based compounds through special fabrication process. The diffusion and thermoelectric properties of Bi-Sb-Te compounds with different fabrication processes are discussed in this research.

摘要 I
Abstract II
致謝 III
圖目錄 VIII
表目錄 XIII
第一章、緒論 1
1.1熱電效應 2
1.1.1 Seebeck效應 2
1.1.2 Peltier效應 3
1.1.3 Thomson效應 4
1.2 熱電材料的應用和其轉換效率 4
1.3 研究目的 6
第二章、文獻回顧 8
2.1 載子濃度對於熱電性質之影響 8
2.2 Bi2Te3化合物半導體材料 9
2.2.1 Bi2Te3晶體結構 10
2.2.2 Bi2Te3內部缺陷 12
2.3 摻雜原子在熱電材料中的影響 14
2.4 Bi2Te3塊材製備方法 21
2.4.1球磨ball milling 22
2.4.2旋熔法melt spinning 22
2.4.3冷壓cold press 22
2.4.4熱壓hot press 23
2.4.5電漿燒結SPS 23
2.5 晶體方向性之影響 24
2.6 非均勻梯度摻雜效應 28
第三章、實驗設計 31
3.1 實驗流程 31
3.2 實驗製備 31
3.2.1 區域熔煉製程 31
3.2.2 粉末冶金冷壓製程 33
3.2.3 粉末冶金熱壓製程 34
3.3 非均勻梯度摻雜製程 34
3.3 熱電傳輸性質量測與晶體結構分析 35
3.3.1 Seebeck特性量測 35
3.3.2 霍爾效應量測 37
3.3.3 熱傳導係數量測 39
3.3.4 X-光結晶繞射分析 40
3.3.5 微結構、形貌與成份分析 41
第四章、鉍銻碲系化合物微結構與熱電特性 42
4.1 材料晶體特性及微結構研究 42
4.1.1區域熔煉試片晶體結構方向性分析 42
4.1.2冷壓試片晶體結構方向性分析 44
4.1.3 熱壓試片晶體結構方向性分析 47
4.2 材料熱電傳輸性質量測分析 49
4.2.1 區域熔煉晶棒之熱電性質 49
4.2.2 冷壓試片之熱電性質 51
4.2.3 熱壓製程之熱電性質量測 53
4.3綜合討論 54
第五章、摻雜效應對鉍銻碲系化合物之熱電特性影響研究 55
5.1 均勻摻雜之鉍銻碲系化合物 55
5.2 非均勻摻雜鉍銻碲系化合物之擴散濃度分析 57
5.2.1 區域熔煉試片擴散摻雜分析 58
5.2.2 冷壓試片擴散摻雜分析 60
5.2.3 熱壓試片擴散摻雜分析 62
5.3非均勻摻雜鉍銻碲系化合物之熱電性質分析 63
5.3.1非均勻摻雜區域熔煉試片之Seebeck特性 64
5.3.2非均勻摻雜冷壓試片之Seebeck特性 65
5.3.3非均勻摻雜熱壓試片之Seebeck特性 67
5.4摻雜原子與晶體缺陷對鉍銻碲系系化合物電性影響之探討 68
第六章、結論 70
參考文獻 72

[1] D. M. Rowe, Thermoelectric Handbook: Macro to Nano, (CRC/Taylor & Francis, Florida, 2006).
[2] D.M. Rowe, CRC handbook of thermoelectrics, (CRC Press, Florida, 1995).
[3] G. J. Snyder and E. S. Toberer, Nature Materials 7, 105 (2008).
[4] G. F. Wang, and T. Cagin, Physical Review B 76, 075201 (2007).
[5] T. Caillat, M. Carle, P. Pierrat, H. Scherrer, and S. Scherrer, Journal of Physics and Chemistry of Solids 53, 1121 (1992).
[6] R. O. Carlson, Journal of Physics and Chemistry of Solids 13, 65 (1960).
[7] J. D. Keys and H. M. Dutton, Journal of Physics and Chemistry of Solids 24, 563 (1963).
[8] Y. Hori, D. Kusano, T. Ito, and K. Izumi, Proceedings of the 18th International Conference on Thermoelectrics, Baltimore, MD, USA, 328–331 (1999).
[9] X. A. Fan, J. Y. Yang, R. G. Chen, H. S. Yun, W. Zhu, S. Q. Bao, and X. K. Duan, Journal of Physics D-Applied Physics 39, 740 (2006).
[10] G. R. Miller, and C. Y. Li, Journal of Physics and Chemistry of Solids 26, 173 (1965).
[11] J. Horak, K. Cermak and L. Koudelka, Journal of Physics and Chemistry of Solids 47, 805-809 (1986).
[12] Z. Starý, J. Horák, M.Stordeur, and M. Stölzer, Journal of Physics and Chemistry of Solids 49, 29 (1988).
[13] J. P. Heremans, V. Jovovic, E. S. Toberer, A. Saramat, K. Kurosaki, A. Charoenphakdee, S. Yamanaka, and G. J. Snyder, Science 321, 554 (2008).
[14] J. Navratil, I. Klichova, S. Karamazov, J. Sramkova, and J. Horak, Journal of Solid State Chemistry 140, 29 (1998).
[15] J. L. Cui, X.B. Xu, Materials Letters 59, 3205 (2005).
[16] J. L. Cui, H.F. Xue, W.J. Xiu, Materials Letters 60, 3669 (2006).
[17] J. L. Cui, Journal of Alloys and Compounds 415, 216-219 (2006).
[18] J. Jiang, L. Chen, Q. Yao, S. Bai, and Q. Wang, Materials Chemistry and Physics 92, 39 (2005).
[19] J. Jiang, L. Chen, S. Bai, Q. Yao, and Q. Wang, Journal of Crystal Growth 277, 258 (2005).
[20] N. A. Sidorenko, N. A. Tmetkova and Z. M. Dashevskii, Superconductor Science and Technology 6, 6246 (1993).
[21] V. Carcelen, P. Hidalgo, J. Rodriguez-Fernandez, and E. Dieguez, Journal of Applied Physics 107, 093501 (2010).
[22] Y. S. Hor, D. Qu, N. P. Ong and R. J. Cava, Journal of Physics: Condensed Matter 22, 375801 (2010).
[23] T. Aizawa, T. Kuji, and H. Nakano, Journal of Alloys and Compounds 291, 248 (1999).
[24] J. Yanga, T. Aizawa, A. Yamamoto, and T. Ohta, Journal of Alloys and Compounds 309, 228 (2000).
[25] C. N. Liao and L. C. Wu, Applied Physics Letters 95, 052112 (2009).
[26] W. J. Xie, X. F. Tang, Y. G. Yan, Q. J. Zhang, and T. M. Tritt, Applied Physics Letters 94, 102111 (2009).
[27] S. S. Kim, S. Yamamoto, T. Aizawa, Journal of Alloys and Compounds 375, 107–113 (2004).
[28] X. A. Fan, J. Y. Yang, W. Zhu, S. Q. Bao, X. K. Duan, C. J. Xiao and K. Li1, Journal of Physics D-Applied Physics 40, 5727–5732 (2007).
[29] X. A. Fan, J. Y. Yang, W . Zhu, S. Q. Bao, X. K. Duan, C. J. Xiao, K. Li, Journal of Alloys and Compounds 461, 9–13 (2008).
[30] T. Kuribayashi, M.-G. Sung, T. Itoh, K. Sassa and S. Asai, Materials Transactions, Vol. 47, No. 9, 2387–2392 (2006).
[31] H. H. Huang, M. P. Lu, C. H. Chiu, L. C. Su, C. N. Liao, J. Y. Huang, H. L. Hsieh, Applied Physics Letters 103, 163903 (2013).
[32] J. Bludska, I. Jakubec, C. Drasar, P. Lostak, J. Horak, Philosophical Magazine and Philosophical Magazine Letters, 87, 325–335 (2006).
[33] C. H. Chiu and C. N. Liao, “A study on the diffusion behavior of Bi-Sb-Te thermoelectric materials,” p.49–50, 國立清華大學碩士論文2011年
[34] R. W. Balluffi, S. M. Allen, and W. C. Carter, Kinetics of Materials, p. 104 (Wiley, New Jersey, 2005).
[35] W. F. Smith, and J. Hashemi, Foundations of Materials Science and Engineering, p. 196–197 (Mc Graw Hill, New York, 2010).