| 摘要: | 近年，因能源枯竭及再生能源的意識抬頭，熱電發電引起廣大關注。熱電材料是一種能將電能與熱能交互轉換的材料，此種材料能夠在足夠的溫差下產生電動勢，達到以熱生電的現象。熱電材料的下一階段為熱電元件、模組，由多對的N-type與P-type熱電塊材串接，使每塊熱電材料在溫差下產生的電壓相加，能夠產生有效、可利用的電能。然而熱電模組的應用環境處於高溫狀態，模組裡的熱電塊材相接處的特性就顯為重要。金屬接觸層置於熱電材料與焊料、電極之間，防止在高溫時外部的焊料及電極元素擴散至熱電塊材內部，金屬接觸層的特性攸關於整熱電模組的整體性能。
本實驗建立在鎂矽錫熱電材料的基礎上，找尋不同種類的金屬材料，其材料必須擁有低電阻率、高機械強度、好的熱穩定性，並且不與熱電試片本身有過多的反應。接續透過不同的製作方式，如塗抹、粉末壓片，冷壓等方式，使其接合於鎂矽錫熱電材料表面上，再進行長時間退火，並於介面處進行電性量測。最後挑選出表現優異的金屬接觸材料來製作出三組單對的熱電元件，進行開路電壓、短路電流及電阻的量測。
;In recent years, thermoelectric power generation has attracted a lot of attention due to energy crisis and the demand of renewable energy. Thermoelectric material is a material that can directly convert electrical energy and thermal energy. These materials can generate electromotive force under a sufficient temperature difference to achieve the phenomenon of generating electricity from heat. The next stage of thermoelectric materials is thermoelectric devices and modules. Multiple pairs of N-type and P-type thermoelectric blocks are connected in series, so that the voltages generated by each thermoelectric material under the temperature difference can be added together, which can generate effective and usable electrical energy. However, the application condition of the thermoelectric module is in a high temperature environment, and the characteristics of the junction of the thermoelectric blocks in the module are very important. The contact metal layer is placed between the thermoelectric material and the electrodes as the solder to prevent the elements from diffusing into the thermoelectric blocks at high temperature. The properties of the contact metal layer are critical to the overall performance of the thermoelectric module.
This study is on the N-type Mg2(SiSn) thermoelectric materials, looking for different kinds of contact metals. The materials must have low resistivity, high mechanical strength, good thermal stability, and do not have too much reaction with the thermoelectric blocks itself. Then, through different production processes, such as coating, powder pressing, cold pressing, annealing, etc., it is bonded to the surface of the N-type Mg2(SiSn) thermoelectric material. Finally, the contact metals with excellent performance were selected to make three sets of single-pair thermoelectric device/elements, and the open-circuit voltage, short-circuit current and resistance were measured. |
