| 摘要: | 隨著能源耗竭與地球暖化問題日益嚴重，全球對永續與環保的重視也持續提升，目前大多數電力仍仰賴非再生能源，不僅對環境造成嚴重污染，也面臨資源逐漸枯竭的危機，開發其它替代能源已成為全球共同的目標。而熱電材料可利用材料內部的溫差產生載子的移動，進而形成電壓差，實現由熱能直接轉換為電能，具備無污染、使用壽命長、體積小等優勢，並可從工業或日常生活中的熱源中回收廢熱，提高能源使用率。然因單一熱電試片的輸出功率有限，實務上通常需將N型與P型試片串接成元件，再組裝成模組，以提高整體輸出功率與轉換效率。因此，本研究聚焦於挑選適用於N型材料的接觸金屬與外側電極金屬，並且符合低接觸電阻、良好的熱穩定性，且不與試片產生過度反應或擴散至試片內部而影響其電性表現。同時，也搭配適當金屬薄片作為焊料功用，以提升模組的機械強度與穩定性，同時維持良好試片特性。
接續本實驗室Mg2SnBi0.02+20at%Mg+4%Mg2Si製程的N型鎂矽錫熱電材料，測試不同接觸金屬片與外側金屬電極進行高溫爐管600°C持溫1小時的的長時間退火，依據電壓與電阻值的量測分析，挑選出最佳的電性及高接合強度的組合，再分別嘗試用直接退火方式與焊接方式與P型試片串接成元件，量測電性後決定模組製作方式。最終，本研究選用厚度30 µm 的鋁片及厚度30 µm 的銀箔，作為N型試片中間接觸金屬層，搭配厚度30 µm 的鈷片為橋接金屬；P型則是使用30 µm 鋁片、30 µm 銀箔及30 µm 錫片作為中間接觸金屬層，搭配厚度80 µm 的鎳片為橋接金屬，兩者分別完成上下金屬片的高溫退火後，最後將鈷片與鎳片間用錫片與導電銀漿焊接串聯成模組，最終製作出0.63v的輸出電壓、11Ω的電阻值與輸出功率為1.7 mW的80對熱電模組。
;With the increasing severity of global warming and the ongoing depletion of fossil fuel resources, the demand for sustainable, eco-friendly, and high-efficiency energy solutions is growing rapidly. Thermoelectric (TE) materials, which enable direct conversion of heat into electricity via temperature gradients, offer distinct advantages such as solid-state operation, long service life, compact size, and zero emissions. These features make them particularly attractive for recovering waste heat from industrial processes, automotive exhaust systems, and even ambient sources in daily life. However, due to the intrinsically low power output of single thermoelectric legs, practical implementations require both n-type and p-type elements to be assembled into devices and further integrated into modules to enhance overall output power and energy conversion efficiency.
This study focuses on optimizing the interfacial design and metallization of n-type Mg₂SnBi₀.₀₂-based thermoelectric materials, fabricated with 20 at% Mg and 4% Mg2Si. Various contact and electrode metal combinations were evaluated in terms of electrical resistivity, thermal stability, and interfacial diffusion behavior, following long-term annealing at 600 °C for 1 hour. The optimized configuration, employing 30 µm aluminum and silver foils as inner contact layers with cobalt as a bridging metal for the n-type leg, and aluminum, silver, and tin foils with nickel bridging for the p-type leg, was selected for module assembly. After completing high-temperature annealing and soldering using tin foils and conductive silver paste, an 80-pair thermoelectric module was successfully fabricated, delivering an output voltage of 0.63 V, internal resistance of 11 Ω, and an output power of 1.7 mW. The results demonstrate the feasibility of stable and efficient metal interfaces for medium-temperature thermoelectric module applications. |
