隨著工業蓬勃的發展與進步，增加了能源的耗損和廢熱的散失。近年來，科學家們致力於開發能源材料，希望解決當前的能源問題。熱電轉換器由固態熱電材料所組成，可透過Seebeck效應將多餘的熱能直接轉換成電能，具有很高的穩定性、體積小、無噪音等等優點。立方晶的熱電材料GeTe具有很高的電/熱導率，為常見的中溫型熱電材料，基於其熱電性質，本研究以GeTe為基底材料，希望透過摻雜銻(Sb)元素產生晶格變形、取代效應或二次相析出，使得聲子產生散射，進而降低熱傳導係數，達到優化熱電性質的目的。相的穩定性、微結構及熱力學行為的相關資訊都能由相圖來提供。本研究也將透過建構Ge-Te-Sb三元系統的液相線投影圖和623K等溫橫截面圖，找出Ge-Te-Sb系列合金穩定存在之相區，並以此為基礎來研究其熱電特性。另外，也會利用真空熔煉法並結合長時間的熱處理，合成多種系列(GeaSb1-aTe, GeSbbTe1-b,…)的熱電材料，量測其熱電性質，並統整實驗結果進行比對，找出熱電性質提升的原因。

The industrial development and growing human activities have caused the increasing energy consumption and waste heat emission. Thermoelectric (TE) generator, which is capable of converting the undesired waste heat into the precious electricity through Seebeck effect, has been considered as one of the sustainability solutions. Cubic GeTe featured with high electrical and thermal conductivity is targeted in this study, and the thermal/electrical transport properties are tuned by the fluctuations in mass and phase region, with respect to the changing Sb doping amounts. The information of phase stability, microstructures and thermodynamic behaviors are illustrated by the isothermal section and liqiudus projection of ternary Ge-Te-Sb system, on the basis of the thermally-equilibrated or the as-quenched alloys. Several series of Sb-incorporated GeTe (GeaSb1-aTe, GeSbbTe1-b,…) are prepared by melt method and heat treatment, the thermoelectric transport properties are found to be correlated strongly with the starting compositions and secondary phases.

摘要 I
Abstract II
目錄 III
圖目錄 VII
表目錄 VII
前言 1
第1章 文獻回顧 6
1-1 相圖 6
1-1-1 Ge-Te二元系統相平衡圖 7
1-1-2 Ge-Sb二元系統相平衡圖 9
1-1-3 Sb-Te二元系統計算相平衡圖 10
1-1-4 Ge-Te-Sb三元系統液相投影圖 12
1-1-5 GeTe-Sb2Te3-Te三元系統等溫橫截面圖 15
1-2 熱電材料 18
1-2-1 GeTe熱電材料 20
1-2-2 Ge-Sb-Te(GST material)相變記憶材料 24
1-2-3 Ge-Sb-Te(GST material)共振鍵結 26
第2章 研究方法 28
2-1 Ge-Te-Sb三元系統液相線投影圖 28
2-1-1 液相線投影圖合金製備 28
2-1-2 液相線投影圖合金分析 29
2-2 Ge-Te-Sb三元系統等溫橫截面圖 31
2-2-1 等溫橫截面圖合金製備 31
2-2-2 等溫橫截面圖合金分析 33
2-3 高溫真空融煉法 34
2-3-1 熱電材料合金製備 36
2-4 熱電性質 39
第3章 結果與討論 40
3-1 Ge-Te-Sb三元系統液相線投影圖 40
3-1-1 首要析出相Te 46
3-1-2 首要析出相Sb2Te3 48
3-1-3 首要析出相γ 50
3-1-4 首要析出相GeSb4Te7 51
3-1-5 首要析出相GeSb2Te4 53
3-1-6 首要析出相Ge2Sb2Te5 57
3-1-7 首要析出相GeTe 61
3-1-8 首要析出相GeSbTe 69
3-1-9 首要析出相δ 72
3-1-10 首要析出相Sb 75
3-1-11 首要析出相Ge 80
3-2 Ge-Te-Sb三元系統液相線投影圖結論 86
3-3 Ge-Te-Sb三元系統623K等溫橫截面圖 87
3-3-1 Sb2Te3+GeSb4Te7+Te三相區 94
3-3-2 β-GeTe+Te兩相區 96
3-3-3 Te+GeSb2Te4兩相區 99
3-3-4 Te+Ge2Sb2Te5+GeSb4Te7三相區 101
3-3-5 Te+Ge2Sb2Te5+β-GeTe三相區 102
3-3-6 α-GeTe+Te兩相區 104
3-3-7 Sb2Te3+GeSb4Te7兩相區 105
3-3-8 Ge2Sb2Te5+GeSb2Te4兩相區 107
3-3-9 β-GeTe+Ge2Sb2Te5+GeSb2Te4三相區 109
3-3-10 α-GeTe+β-GeTe兩相區 111
3-3-11 Sb2Te3+γ兩相區 113
3-3-12 γ+GeSb4Te7兩相區 114
3-3-13 γ+GeSb4Te7+β-GeTe三相區 117
3-3-14 γ+δ兩相區 118
3-3-15 δ+β-GeTe兩相區 120
3-3-16 Ge+β-GeTe+δ三相區 123
3-3-17 δ單相區 128
3-3-18 Sb+δ兩相區 131
3-3-19 Ge+Sb+δ三相區 132
3-3-20 Ge+δ兩相區 133
3-4 Ge-Te-Sb三元系統623K等溫橫截面圖結論 134
3-5 Ge-Te-Sb系列合金之熱電性質 135
3-5-1 Sb取代Ge/Te系列合金之熱電性質 137
3-5-2 GeTe/Sb2Te3系列合金之熱電性質 151
3-5-3 穿透式電子顯微鏡(TEM)鑑定 158
3-5-4 Ge-Te-Sb之相變化行為 164
3-6 Ge-Te-Sb系列合金之熱電性質結論 167
第4章 結論 175
4-1 相圖 175
4-2 Ge-Te-Sb系列合金熱電性質 176
第5章 參考文獻 177

[1] M. S. Dresselhaus, G. Chen, M. Y. Tang, R. G. Yang, H. Lee, D. Z. Wang, et al., "New Directions for Low-Dimensional Thermoelectric Materials," Advanced Materials, vol. 19, pp. 1043-1053, 2007.
[2] W. S. L. J. F. Li, L. D. Zhao And M. Zhou, "High-Performance Nanostructured Thermoelectric Materials," Npg Asia Materials, Vol. 2, pp. 152-158, 2010.
[3] X. Zhang And L.-D. Zhao, "Thermoelectric Materials: Energy Conversion Between Heat And Electricity," Journal Of Materiomics, Vol. 1, pp. 92-105, 2015.
[4] C. Wood, "Materials For Thermoelectric Energy Conversion," Rep. Prog. Phys., Vol. 51, pp. 459-539, 1988.
[5] A. J. Minnich, M. S. Dresselhaus, Z. F. Ren, And G. Chen, "Bulk Nanostructured Thermoelectric Materials: Current Research And Future Prospects," Energy & Environmental Science, Vol. 2, P. 466, 2009.
[6] T. M. Tritt, "Thermoelectric Phenomena, Materials, And Applications," Annual Review Of Materials Research, Vol. 41, pp. 433-448, 2011.
[7] M. Zhao, J. Zhang, N. Gao, P. Song, M. Bosman, B. Peng, Et Al., "Actively Tunable Visible Surface Plasmons In Bi2Te3 And Their Energy-Harvesting Applications," Advanced Materials, Vol. 28, Pp. 3138-3144, 2016.
[8] E. M. Levin, M. F. Besser, And R. Hanus, "Electronic And Thermal Transport In GeTe: A Versatile Base For Thermoelectric Materials," Journal Of Applied Physics, Vol. 114, p. 083713, 2013.
[9] J. Li, X. Zhang, S. Lin, Z. Chen, And Y. Pei, "Realizing The High Thermoelectric Performance Of GeTe By Sb-Doping And Se-Alloying," Chemistry Of Materials, Vol. 29, pp. 605-611, 2017.
[10] D. Wu, L. D. Zhao, S. Hao, Q. Jiang, F. Zheng, J. W. Doak, Et Al., "Origin Of The High Performance In GeTe-Based Thermoelectric Materials Upon Bi2Te3 Doping," J Am Chem Soc, Vol. 136, pp. 11412-11419, 2014.
 
[11] R. Sankar, D. P. Wong, C. S. Chi, W. L. Chien, J. S. Hwang, F.-C. Chou, Et Al., "Enhanced Thermoelectric Performance Of GeTe-Rich Germanium Antimony Tellurides Through The Control Of Composition And Structure," Crystengcomm, Vol. 17, pp. 3440-3445, 2015.
[12] S. Perumal, S. Roychowdhury, And K. Biswas, "High Performance Thermoelectric Materials And Devices Based On GeTe," Journal Of Materials Chemistry, Vol. 4, pp. 7520-7536, 2016.
[13] O. H., "GeTe (Germanium Tellurium)," J. Phase Equilib., vol. 21, p. 496, 2000.
[14] O. H., "GeSb (Germanium Antimony)," J. Phase Equilib., vol. 22, pp. 91-92, 2001.
[15] G. Ghosh, "The-Sb-Te-Antimony-Tellurium-System," J. Phase Equilib., vol. 15, 1994.
[16] P. F. Poudeu And M. G. Kanatzidis, "Design In Solid State Chemistry Based On Phase Homologies. Sb4Te3 And Sb8Te9 As New Members Of The Series (Sb2Te3)m.(Sb2)n," Chem Commun (Camb), pp. 2672-2674, 2005.
[17] C. H. B. Legendre, S. Bordas, M. T. Clavaguera-Mora, "Phase Diagram Of The Ternary System Ge-Sb-Te. I. The Subternary GeTe-Sb,Te,-Te," Thermochimica Acta,, vol. 78, pp. 141-157, 1984.
[18] V. A. S. V. I. Kosyakov, L. E. Shelimova, F. A. Kuznestsov, And V. S. Zemskov, "Topological Characterization Of The Ge-Sb-Te Phase Diagram," Inorganic Materials, Vol. 36, pp. 1004-1017, 2000.
[19] J. L. F. Da Silva, A. Walsh, And H. Lee, "Insights Into The Structure Of The Stable And Metastable (GeTe)m(Sb2Te3)n Compounds," Physical Review B, Vol. 78, 2008.
[20] P. Vaqueiro And A. V. Powell, "Recent Developments In Nanostructured Materials For High-Performance Thermoelectrics," Journal Of Materials Chemistry, Vol. 20, p. 9577, 2010.
[21] G. J. Snyder, A. E. S. Toberer, "Complex Thermoelectric Materials," Nature Materials, Vol. 7, pp. 105-114, 2008.
[22] L. Yang, J. Q. Li, R. Chen, Y. Li, F. S. Liu, And W. Q. Ao, "Influence Of Se Substitution In GeTe On Phase And Thermoelectric Properties," Journal Of Electronic Materials, Vol. 45, pp. 5533-5539, 2016.
[23] A. V. Kolobov, P. Fons, And J. Tominaga, "P-Type Conductivity Of GeTe: The Role Of Lone-Pair Electrons," Physica Status Solidi (B), Vol. 249, pp. 1902-1906, 2012.
[24] S. Perumal, S. Roychowdhury, D. S. Negi, R. Datta, And K. Biswas, "High Thermoelectric Performance And Enhanced Mechanical Stability Of P-Type Ge1–XSbxTe," Chemistry Of Materials, Vol. 27, pp. 7171-7178, 2015.
[25] E. M. Levin, "Effects Of Ge Substitution In GeTe By Ag Or Sb On The Seebeck Coefficient And Carrier Concentration Derived From Te125NMR," Physical Review B, Vol. 93, 2016.
[26] P. N. Bartlett, S. L. Benjamin, C. H. De Groot, A. L. Hector, R. Huang, A. Jolleys, Et Al., "Non-Aqueous Electrodeposition Of Functional Semiconducting Metal Chalcogenides: Ge2Sb2Te5 Phase Change Memory," Mater. Horiz., Vol. 2, pp. 420-426, 2015.
[27] T. Rosenthal, M. N. Schneider, C. Stiewe, M. Döblinger, And O. Oeckler, "Real Structure And Thermoelectric Properties Of GeTe-Rich Germanium Antimony Tellurides," Chemistry Of Materials, Vol. 23, pp. 4349-4356, 2011.
[28] K. Shportko, S. Kremers, M. Woda, D. Lencer, J. Robertson, And M. Wuttig, "Resonant Bonding In Crystalline Phase-Change Materials," Nature Materials, Vol. 7, pp. 653-658, 2008.
[29] S. Lee, K. Esfarjani, T. Luo, J. Zhou, Z. Tian, And G. Chen, "Resonant Bonding Leads To Low Lattice Thermal Conductivity," Nat Commun, Vol. 5, p. 3525, Apr 28 2014.
[30] S. Gorsse, P. Bauer Pereira, R. Decourt, and E. Sellier, "Microstructure Engineering Design for Thermoelectric Materials: An Approach to Minimize Thermal Diffusivity†," Chemistry of Materials, vol. 22, pp. 988-993, 2010.