熱電材料有極大的潛力解決目前廢熱大量散失的問題。藉由熱電模組，能夠將廢熱轉換為可利用的電能。熱電元件間包含了許多的接點，當這些元件在長時間高溫下運作下，擴散導致的界面反應會使得穩定性下降，為了避免銲料與熱電材料直接接觸，常用的手段便是在接點處引用阻障層來降低反應性，進而提升熱電元件的品質。
Bi2Te3是市面上最為常見的熱電材料。Co及Ni是常見的阻障層。本研究採用電鍍法製備Co/Bi2Te3反應偶以及Ni/Bi2Te3反應偶。藉由短時間的熱處理提供動力學依據，以提供Co及Ni作為Bi2Te3熱電材料阻障層的合宜性與模組可靠性的探討基礎。本研究也致力於Bi-Co-Te以及Ni-Bi-Te三元系統相圖之研究，以長時間的反應結果提供熱力學依據。除了便於探討界面反應外，相圖能夠提供基礎的材料知識，平衡驅動力的方向，甚至作為相關多元系統的開發基礎。
關於Bi-Co-Te系統相平衡實驗的部分，研究發現，該系統在500°C以下並不存在三元化合物。根據本研究之相平衡實驗以及相關二元系統相圖，推測出500°C等溫橫截面圖。500°C等溫橫截面圖總共有Co、Liquid Ⅰ、Liquid Ⅱ、CoTe、CoTe2、Bi2Te3及(Bi2)m(Bi2Te3)n共7個單相區，並且含5個三相區，並且發現(Bi2)m(Bi2Te3)n以及Bi2Te3對Co溶解度極低。
關於Ni-Bi-Te系統相平衡實驗的部分，研究發現，該系統在500°C以下並不存在三元化合物。並且發現一個連續固溶體Ni(Bi,Te)。根據本研究之相平衡實驗以及相關二元系統相圖，推測出500°C等溫橫截面圖。500°C等溫橫截面圖總共有Ni、Ni3Te2、NiTe0.775、Liquid Ⅰ、Liquid Ⅱ、Ni(Bi,Te)、Bi2Te3及(Bi2)m(Bi2Te3)n共8個單相區，並且含5個三相區，並且發現(Bi2)m(Bi2Te3)n以及Bi2Te3對Ni溶解度極低。
關於Co/Bi2Te3界面反應實驗的部分，於300°C Co/Bi2Te3界面反應實驗生成一複雜相(Bi2)m(Bi2Te3)n以及CoTe，界面處的擴散路徑為Co/ CoTe/溶解較多Bi的CoTe/(Bi2)m(Bi2Te3)n /Bi2Te3，主要擴散元素為Te。將反應升高至400°C，生成相並無變化，僅有厚度發生變化。界面處的擴散路徑仍為Co/ CoTe/ 溶解較多Bi的CoTe/(Bi2)m(Bi2Te3)n /Bi2Te3，主要擴散元素為Te。於500°C中，生成相為液相Bi、(Bi2)m(Bi2Te3)n以及CoTe，並且觀察到反應層是由兩個區塊組成，其中一個區塊僅生成CoTe相；而另一個區塊則是由Liquid Bi和(Bi2)m(Bi2Te3)n和溶解較多Bi的CoTe所組成。界面處的擴散路徑為 Co/CoTe /溶解較多Bi的CoTe + Liquid Bi + (Bi2)m(Bi2Te3)n /Bi2Te3，主要擴散元素為Te。
關於Ni/Bi2Te3界面反應實驗的部分，於500°C Ni/Bi2Te3界面反應中，生成相為Ni(Bi,Te)以及(Bi2)m(Bi2Te3)n。界面處的擴散路徑為 Ni / Ni(Bi,Te)/ (Bi2)m(Bi2Te3)n / Bi2Te3。

Thermoelectric materials have great potential to solve the problem of significant waste heat dissipation. By utilizing thermoelectric modules, waste heat can be converted into usable electrical energy. Thermoelectric devices consist of many junctions.When these components operate at high temperatures for a long time, the interfacial reaction caused by diffusion will reduce the stability. To prevent direct contact between solder and thermoelectric materials, a commonly used approach is to introduce barrier layers at the junctions to reduce reactivity and enhance the quality of thermoelectric devices.
Bi2Te3 is the most commonly used thermoelectric material on the market. Co and Ni are common barrier layers. This study employed electroplating methods to prepare Co/Bi2Te3 and Ni/Bi2Te3 reaction couples. Short-term heat treatment was utilized to provide kinetic insights and establish a foundation for evaluating the suitability and reliability of Co and Ni as barrier layers for Bi2Te3 thermoelectric materials. The study also focused on the phase diagram of the Bi-Co-Te and Ni-Bi-Te ternary systems to provide thermodynamic insights based on long-term reaction results. In addition to facilitating the investigation of interface reactions, phase diagrams offer fundamental material knowledge, direction of equilibrium driving forces, and serve as a basis for the development of related multicomponent systems.
Regarding the equilibrium experiments of the Bi-Co-Te system, it was found that no ternary compounds exist at 500°C. Based on the equilibrium experiments of this study and relevant binary phase diagrams, a 500°C isothermal cross-section diagram was built. The diagram includes seven single-phase regions: Co, Liquid I, Liquid II, CoTe, CoTe2, Bi2Te3, and (Bi2)m(Bi2Te3)n, as well as five three-phase regions. It was observed that (Bi2)m(Bi2Te3)n and Bi2Te3 have extremely low solubility in Co.
Regarding the equilibrium experiments of the Ni-Bi-Te system, it was found that no ternary compounds exist at 500°C. A continuous solid solution Ni(Bi,Te) was discovered. Based on the equilibrium experiments of this study and relevant binary phase diagrams, a 500°C isothermal cross-section diagram was built. The diagram includes eight single-phase regions: Ni, Ni3Te2, NiTe0.775, Liquid I, Liquid II, Ni(Bi,Te), Bi2Te3, and (Bi2)m(Bi2Te3)n, as well as five three-phase regions. It was observed that (Bi2)m(Bi2Te3)n and Bi2Te3 have extremely low solubility in Ni.
Regarding the interface reaction experiments of Co/Bi2Te3 at 300°C, a complex phase (Bi2)m(Bi2Te3)n and CoTe were formed at the interface. The diffusion path at the interface was found to be Co/CoTe/CoTe with more dissolved Bi/(Bi2)m(Bi2Te3)n/Bi2Te3. The main diffusion element is Te. Increasing the reaction temperature to 400°C did not result in any phase changes; only thickness variations were observed. The diffusion path at the interface remained Co/CoTe/CoTe with more dissolved Bi/(Bi2)m(Bi2Te3)n/Bi2Te3. The main diffusion element is Te. At 500°C, the formation phases were liquid Bi, (Bi2)m(Bi2Te3)n, and CoTe. A two-layered reaction zone was observed, with one layer consisting of only CoTe and the other composed of Liquid Bi, (Bi2)m(Bi2Te3)n, and CoTe with more dissolved Bi. The diffusion path at the interface was Co/CoTe/CoTe with more dissolved Bi + Liquid Bi + (Bi2)m(Bi2Te3)n/Bi2Te3. The main diffusion element is Te.

Regarding the interface reaction experiments of Ni/Bi2Te3 at 500°C, the formation phases were Ni(Bi,Te) and (Bi2)m(Bi2Te3)n. The diffusion path at the interface was Ni/Ni(Bi,Te)/(Bi2)m(Bi2Te3)n/Bi2Te3.

摘要 i
Abstract iii
目錄 vi
圖目錄 viii
表目錄 xii
第1章 前言 1
第2章 文獻回顧 3
2.1 熱電 3
2.1.1 熱電效應 4
2.1.2 Bi2Te3 5
2.1.3 熱電模組 7
2.2 界面反應 8
2.2.1 Co/Te界面反應 11
2.2.2 Co/Bi界面反應 11
2.2.3 Ni/Te界面反應 11
2.2.4 Ni/Bi界面反應 12
2.2.5 Co/Bi2(Te,Se)3界面反應 13
2.2.6 Ni/Bi2Te3界面反應 13
2.3 相圖 16
2.3.1 Bi-Te相圖 19
2.3.2 Bi-Co相圖 22
2.3.3 Co-Te相圖 24
2.3.4 Ni-Te相圖 26
2.3.5 Bi-Ni相圖 28
2.3.6 Bi-Co-Te 670k等溫橫截面圖 31
2.3.7 Ni-Bi-Te等溫橫截面圖 31
第3章 研究方法 33
3.1 界面反應 33
3.1.1 Bi2Te3基材製備 33
3.1.2 Co/ Bi2Te3反應偶製備 33
3.1.3 樣品分析 34
3.2 等溫橫截面圖 36
3.2.1 合金點配置 36
3.2.2 樣品分析 36
第4章 結果與討論 38
4.1 Co-Bi-Te 500℃等溫橫截面圖 38
4.1.1 Co+CoTe+Liquid Ⅰ 三相區 40
4.1.2 CoTe +Liquid Ⅰ 兩相區 43
4.1.3 CoTe+(Bi2)m(Bi2Te3)n+Liquid Ⅰ 三相區 46
4.1.4 CoTe2 + Bi2Te3兩相區 49
4.1.5 CoTe2+Bi2Te3+Liquid Ⅱ 三相區 52
4.2 Co/ Bi2Te3 500℃界面反應 55
4.2.1 Co/ Bi2Te3 500℃界面反應結果 55
4.2.2 Co/ Bi2Te3 500℃界面反應分析與機制 63
4.3 Co-Bi-Te 400℃等溫橫截面圖 67
4.4 Co/Bi2Te3 400℃界面反應 68
4.4.1 Co/Bi2Te3 400℃界面反應結果 68
4.4.2 /`Co/Bi2Te3 400℃界面反應分析與機制 78
4.5 Co-Bi-Te 300℃等溫橫截面圖 81
4.6 Co/ Bi2Te3 300℃界面反應 83
4.6.1 Co/ Bi2Te3 300℃界面反應結果 83
4.6.2 Co/Bi2Te3 300℃界面反應分析與機制 91
4.7 Ni-Bi-Te 500℃等溫橫截面圖 95
4.7.1 Ni+Ni(Bi,Te)兩相區 97
4.7.2 Ni3Te2+Ni(Bi,Te)兩相區 100
4.7.3 Ni(Bi,Te) 單相區 102
4.7.4 Ni(Bi,Te) +Liquid Ⅰ 兩相區 105
4.7.5 Ni(Bi,Te)+ Bi2Te3+Liquid Ⅱ 三相區 108
4.8 Ni/Bi2Te3 500℃界面反應 111
4.8.1 Ni/ Bi2Te3 500℃界面反應結果 111
4.8.2 Ni/ Bi2Te3 500℃界面反應分析與機制 121
第5章 結論 124
第6章 參考文獻 126

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