由於國際能源需求不斷上升以及溫室效應日益嚴重，乾淨、可再生的能源近年來不斷在發展中，而目前使用的石化燃料大部分的功率消耗來自於廢熱的逸散，熱電材料由於可直接將熱能與電能轉換，對於廢熱回收為重要的研究領域，此外，影響熱電材料轉換效率主要取決於其熱電優值(ZT)，改善熱電優值也是目前研究的重點。 本實驗研究新興中溫P型熱電材料BiCuSeO及低溫P型熱電材料MgAgSb，以別於以往使用熱壓或火花電漿燒結，我們藉由球磨至奈米尺寸並均勻混合後，搭配冷壓及調整不同退火方式、溫度及時間等參數進行反應，成功製備出Seebeck係數最高達448.86(μV/K)及最低熱導率達0.272(W/m-K)的Bi_0.92 Ag_0.08 CuSeO樣品，以及P型MgAgSb塊材。最後使用P型Bi_0.92 Ag_0.08 CuSeO與N型Mg_2 Si_0.4 Sn_0.6製作出的模組在溫差46度時，最大輸出功率達到43.1(μW)。 ;Due to the demand of energy and the concern on pollution, renewable energy has attracted much attention in recent years. Among them, thermoelectric energy can be achieved by waste heat recovery from direct conversion from thermal energy to electricity. The conversion efficiency of thermoelectric materials is mainly determined by its thermoelectric figure of merit (ZT). The improvement of the ZT is keen for current research. In this thesis, The ZTs of medium- and low-temperatured P-type thermoelectric material BiCuSeO and MgAgSb were studied, respectively. Different from conventional hot pressing or spark plasma sintering process, we used ball-milling technique to obtain nanometer-sized powders, and then cold-pressed the powders and annealed at different temperatures and time to study P-type MgAgSb and Bi0.92Ag0.08CuSeO bulks. High Seebeck coefficient of 448.86 (μV/K) and a minimum thermal conductivity of 0.272 (W/m-K) were achieved. Eventually, a thermoelectric module was fabricated using P-type Bi0.92Ag0.08CuSeO and N-type Mg2Si0.4Sn0.6, and the maximum output power reached 43.1 (μW) at a temperature difference of 46 degrees.
