臺灣博碩士論文加值系統

銻化鍺(GeTe)與銻化錫(SnTe)為目前常見的 P 型的中溫熱電材料。為了提升熱電材料的優值(ZT)，本論文中利用垂直式布里茲曼法(Vertical Bridgman method)製備三元化合物 Ge1-xSnxTe（x = 0 , 0.2 , 0.4 , 0.6 , 0.8 , 1）。詳細的分析流程，包含粉未X-光繞射（X-ray diffraction）、拉曼光譜(Raman)、光學金相顯微鏡(OM)、掃描式電子顯微鏡(SEM)、電子微探儀（EPMA）與穿透式電子顯微鏡(TEM)以分析材料晶體結構與結晶品質。並在50K ~ 400K進行熱電性質量測，以分析材料之熱電性質與其對溫度之相依性。
依據光學顯微鏡、掃描式電子顯微鏡與穿透式電子顯微鏡鑑定的結果，發現在成分x= 0 ~ 0.4的晶體中觀察到次晶界（subgrain boundary）及雙晶（micro-twins），且可判定產生雙晶的面皆為 {220} 。並得知此材料從高溫降至低溫時，產生麻田散（β→α）相變化。
在熱電量測分析結果顯示，利用混合晶體（Mixed crystal）的方式成功降低晶格熱導，使得熱導降低，在晶體 x = 0.4 , 50K 時有最低的熱導 28.28 (mw/cm-K) ；相同的晶體在 400K 時有最高的 ZT 值為 0.038 ，比銻化鍺與銻化錫在 400K 的 ZT 值約高 10 倍。

A series of ternary compounds Ge1-xSnxTe with x = 0, 0.2 , 0.4, 0.6, 0.8, 1.0 were successfully synthesized by the vertical Bridgman method. These materials all have excellent crystallinity with either rhombohedral structure（x = 0 – 0.6）or face centered structure（x = 0.8 – 1.0）at room temperatures, according to XRD and AEM. In the materials with x = 0 – 0.6, subgrain boundaries and micro-twins, characteristics of a martensitic type transformation from high temperature fcc structure to low temperature rhombohedral structure, were observed by OM, SEM and TEM. Despite the presence of ample high-angle grain boundaries, no subgrains and twins were observed in the materials with x = 0.8 – 1.0 lack of such transformation upon cooling.
Thermoelectric properties of these materials were characterized at 50 – 400 K. Experimental results reveal that the thermal conductivities of these materials have been successfully reduced either by the presence of subgrains and twins in the materials with x = 0 – 0.6 by the presence of high-angle boundaries in the material with x = 0.8 – 1.0. Among all synthesized materials, the one with x = 0.4 has the lowest conductivity of 28.28（mW/cm-K）at 50K. This same material also exhibit the highest ZT value of 0.038 at 400 K, which is about 10 times higher than those of GeTe and SnTe commonly used as thermoelectric material at middle temperatures.

誌謝………………………………………………………Ⅰ
摘要………………………………………………………Ⅱ
英文摘要………………………………………………………Ⅲ
目錄………………………………………………………Ⅳ
圖目錄…………………………………………………………Ⅶ
表目錄……………………………………………………XII
一、前言……………………………………………………1
二、研究背景與理論基礎…………………………………5
2.1研究背景………………………………………………5
2.2基礎理論與文獻回顧………………………………8
2.2.1電學性質……………………………………………8
2.2.2熱電材料基本性質………………………………11
2.2.3熱電現象……………………………………………12
2.2.3.a 席貝克效應…………………………………12
2.2.3.b 珀爾帖效應……………………………………16
2.2.3.c 湯姆森效應……………………………………16
2.2.4熱傳導現象……………………………………17
2.2.5 拉曼光譜…………………………………………19
三、實驗方法與步驟……………………………………21
3.1實驗流程圖………………………………………….22
3.2材料預混………………………………………………23
3.2.1拉管與石英管清洗………………………………23
3.2.2石英管鍍碳膜………………………………………23
3.2.3 元素稱重填管及封管……………………………24
3.2.4 高溫搖擺…………………………………………27
3.3晶體成長………………………………………………29
3.3.1垂直式布里茲曼晶體成長系統……………………29
3.3.2 溫度梯度量測……………………………………31
3.4.材料結構與成份分析………………………………35
3.4.1粉末X光繞射………………………………………35
3.4.2.光學金相顯微鏡分析……………………………35
3.4.3電子顯微鏡分析（SEM、EPMA）…………………36
3.4.4 穿透式電子顯微鏡試片製作……………………37
3.5熱電特性量測………………………………………38
3.5.1電阻率量測………………………………………38
3.5.2 席貝克係數和熱傳導量測原理與方法………40
四、實驗結果與討論……………………………………43
4.1晶體結晶性分析……………………………………43
4.1.1晶體外觀……………………………………………43
4.1.2 電子微探分析……………………………………44
4.1.3粉末X光繞射………………………………………47
4.1.4 拉曼光譜分析……………………………………51
4.2.金相和掃描式電子顯微鏡結果分析………………53
4.2.1. 金相結果分析……………………………………54
4.2.2掃描式電子顯微鏡結果分析………………………56
4.3.解析型穿透式電子顯微鏡分析結果………………60
4.3.1 選區繞射圖………………………………………60
4.3.2材料缺陷分析………………………………………75
4.4.熱電特性分析………………………………………81
4.4.1電阻率量測分析……………………………………81
4.4.2席貝克係數…………………………………………83
4.4.3熱傳導係數…………………………………………86
4.4.4 ZT值………………………………………………88
五、結論…………………………………………………89
參考資料…………………………………………………91

１. Terry M. Tritt & Mas Subramanian MRS Bulletin TE Theme, March 2006
2. Susan M. Kauzlarich,*a Shawna R. Browna and G. Jeffrey Snyderb, Zintl phases for thermoelectric devices, The Royal Society of Chemistry 2007, Dalton Trans., 2007, 2099–2107
3. George S. Nolas, Joe Poon, and Mercouri Kanatzidis, MRS-31-199-06
4. S.K Plachkova and T I Georgiev, J. Phys.: Condens. Matter 5 (1993) 67-84
5. E. Rogacheva and N. Dzyubenko, 18th International Conference on Thermoelectrics (1 999) 226-229
6. E.I. Rogacheva', O.N. Nashchekina', Ye.0. Vekhov'. and M.S. Dresselhaus', 220d International Confercnce on 'l'hcrmoelectrics (2003), 346-349
7. Rupert Marx and Klaus-Jurgen Range*, Journal of the Less-Common Metal, 155(1989)49-59
8. W Rehwald and G K Lang, J.Phys. C: Solid State Phys., Vol. 8, 1975 3287-3296
9. A.I. Lebedev and I.A. Sluchinskaya Physics of the Solid State, 2007, Vol. 49, No. 6, pp. 1132-1141
10. J.N. Bierly, L. Muldawer and O. Beckman, ACTA METALLURGICA, 11, 447-454 (1963)
11. Prif. itfrued Madelung, Semiconductors-Basic Data, 198-199
12. Thaddeusb. B . Massalski , Sinary Alloy(second edition) phase
diagrams v2 2009(1996.5).
13. R. D. Vengrenovich, M. O. Stasik, I. A. Lopatnyuk, Z. P. Tsalyi, and S. D. Tkacheva, Russian Physics Journal 36,103-107(1993)

14. Thaddeusb. B . Massalski ,Sinary Alloy(second edition) phase
diagrams v3 3402(1996.5).
15. Villars, P. Prince, Alan, Okamoto, H., Handbook of Ternary Alloy Phase Diagrams 11622(1994)
16. Seebeck, T. J., Magnetic polarization of metals and minerals,
Abhandlungen der Deutschen Akademie Wissenschaften zu Berlin, 265 (1823).
17. Gerald Mahan, Brian Sales, and Jeff Sharp, Physics Today, March 1997,42 (1997).
18. N.Scoville, C.Bajgar, J.P.Fleurial, and J.Vandersande, Thermal conductivity reduction in SiGe alloys by the addition of nanophase particles, NanoStuctured Materials, Vol. 5, No 2, pp.207-223, 1995.
19. Seebeck, T. J., Magnetic polarization of metals and minerals,
Abhandlungen der Deutschen Akademie Wissenschaften zu Berlin, 265 (1823).
20. Pollock, D. D.,Thermoelectricity:theory, Thermometry, tool,
ASTM Special Technical Publication 852, American Society for
Testing and Materials, Philadelphia, PA, 1985.
21. D.M.Rowe, CRC handbook of thermoelectrics, 1-131(1995).
22. Seebeck, T. J., Uber deen magnetismus der gavenische kette, Abh. K. Akad. Wiss. Berlin, 289 (1821).
23. Seebeck, T. J., Ann. Phys. (Leipzig)[2], 6,1(1826)
24. Seebeck, T. J., Methode, Platinatiegel auf ihr chemische reinheit durck thermomagnetismus zu prufen, Sschweigger`s J.Phys.,46,101(1826).
25. Peltier, J.C., Nouvelles experinces sur la caloricite des conurans electrique, Ann. Chim., LV1 371(1834)
26. Pollock,D.D.,Thermoelectircity:theory,Thermome-try,tool, ASTM Special Technical Publication 852, American Society for Testing and Materials, Philadelphia, PA(1985)
27. H.J.Goldsmid, “Electronic Refrigeration”, 1-194(1986)
28. W.Thomson, On a mechanical theory of thermo-electic currents, Proceeding of the Royal Society of Edinburgh, 91(1851)
29. Pollock, D.D., Physicd of Engineering Materials, Prentice Hall, Englewood Cliffs,NJ, 330(1990)
30. W. Thomson, An account of Carnot’s theory of the motive power of heat, Proc. R. Soc. Edinburgh, 16,541(1849)
31. 李雅明，【固態電子學】，91-121，235-257 (1997).
32. H.J.Goldsmid, “Electronic Refrigeration”, 1-194 (1986).
33. David Jiles, “Introduction to the Electronic Properties of Materials”, 46-48(1995).
34. Dieter K. Schroder, “Semiconductor material and device
characterization”, 1990.
35. Koji Yano and Takashi Katoda, J. Appl. Phys. 70, 7036 (1991).
36. Dieter K. Schroder, Semiconductor material and device characterization, 2rd ed., Wiley-Interscience, New York, 1998.
37.R. A. Laudise, The Growth of Single Crystal, Prentice-Hall, Inc. p.41.
38.馮念中,利用垂直式Brigman法成長Ge1-xSnxTe晶體與性質分析 ,2006
39. Scanning Electron Microscopy and X-ray Microanalysis", 3rd Ed. J.I.Goldstein et al. (Plenum Press, 2003)
40.何明翰, 銻化鋅鎘晶體之熱電特性研究, 2003
41. Grier, D., McCarth, G., Seidler, D., Boudjok. P., North Dakota State Univ., Fargo, ICDD Grant-in-Aid（1993）
42. H. Wan Shu, S. Jaulmes, R. Ollitrault-Fichet and J Flahaut JSSCBI 6948-54 1987
43. R.T.Yakimova, E.P.Trifonova, L.Karagiozov and S. Petrov CRTEDF 19K109- 1984
44. Marx, R., Range, K.-J. JCOMAH 155 49 1989
45. Bruce A. Cook A Xuezheng Wei A Joel L. Harringa A Matthew J. Kramer J Mater Sci (2007) 42:7643–7646
46. E. I . Rogacheva. Oscillations in thickness dependences of room
temperature Seebeck Coefficient in SnTe thin films.P2, 2005.