本研究的主軸為氧化物熱電材料-鉍銅硒氧(BiCuSeO)，BiCuSeO屬於p型半導體，因其特殊的層狀結構，具有本質低的熱傳導率和高席貝克係數，是近來新興的氧化物熱電材料。但是相對於傳統的合金熱電材料而言，其導電率偏低，有待改善，通常可藉由合理的調控，例如摻雜低價數離子取代鉍(Bi3+)引入電洞，藉此提高導電率，進而提升熱電優值(ZT)。因此本研究的其中一部分即是藉由摻雜Eu2+來探討其對BiCuSeO的影響。另外，於今年(2016)有研究指出BiCuSeO並非典型的離子化合物，各個元素不是以單一價態存在，有變價現象，而合成氣氛對元素價態影響甚大，故本研究的另一部分試圖探討不同氣氛對合成BiCuSeO及其性質之影響。
論文內容將分為兩個部份，分別探討不同合成氣氛與不同銪摻雜量對BiCuSeO的影響。實驗上皆以固相反應法合成BiCuSeO樣品，再進行各項材料分析，包含XRD、SEM、EBSD、TEM、DSC、密度量測、席貝克係數、霍爾量測、導電率、熱傳導率、熱電優值等性質分析。
實驗結果顯示，在100ppm O2-Ar、Ar、3% H2-Ar三種不同氣氛條件下均可藉由固相反應法在800°C下合成BiCuSeO之純相，但Rietveld晶體結構分析發現三組樣品的氧位置佔有率不同，依序為1.12、1.01、0.69，而晶格常數也有變化，大小次序恰與其相反。在不同氣氛下合成的BiCuSeO席貝克係數皆為正值，屬於p型材料，席貝克係數大小依序為Ar組 > 100ppm O2-Ar組 > 3% H2-Ar組。三組樣品導電率在室溫以上皆隨溫度上升而下降，屬於金屬型導電特性，導電率大小依序為3% H2-Ar組 > 100ppm O2-Ar組 > Ar組，但當溫度低於213K，在Ar氣氛合成之樣品其導電率隨溫度上升而上升，屬半導體型導電特性。
Bi1-xEuxCuSeO(x=0, 0.05, 0.10, 0.15)均可藉由固相反應法在750°C下合成，樣品皆呈現單一純相，摻雜量可達15%仍未超出固溶極限。晶格常數隨摻雜量增加而上升，可間接證明Eu已摻雜進入主體晶格中。摻雜Eu之樣品席貝克係數仍為正值，沒有改變p型屬性，但席貝克係數隨摻雜量增加而下降。摻雜Eu樣品的導電率在測量溫度範圍(約300~700K)內皆隨溫度上升而下降，屬於金屬型導電特性，其導電率大小隨摻雜量增加而上升。

In this work, the effects of oxygen partial pressure and Eu doping on the phase formation and the electrical and thermoelectric properties of BiCuSeO were studied. The undoped samples were sintered at 800 °C in different atmospheres, including 100ppm O2 Ar, Ar, and 3% H2 Ar. Although the BiCuSeO phase could be obtained under all three ambiences, the Rietveld structural analyses showed that the oxygen site occupancy in the obtained phase was 1.12, 1.09, and 0.69, respectively. The lattice constants of the samples were increased as the oxygen deficiency increased. All the samples showed a positive Seebeck coefficient, indicating a p-type electrical conductivity. The samples sintered in Ar had the largest Seebeck coefficient while those sintered in 3% H2-Ar had the lowest one. The values of the electrical conductivity of the samples sintered in different ambiences displayed an opposite order as that of Seebeck coefficients. Above room temperature (RT), all three groups of samples showed a metallic electrical conductivity. However, below 213 K the electric conductivity of the samples sintered in Ar showed a semiconductor behaviour. Bi1-xEuxCuSeO (x=0-0.15) samples of a pure phase were sintered in Ar at 750°C. The lattice constants increased as the Eu doping increased, indicating that the Eu2+ ions were indeed entered the crystal lattice. The Seebeck coefficients of the Eu doped samples remained positive but the values decreased. Over the entire measured temperature range (300-700K), the electrical conductivity of the Eu doped samples decreased as the temperature increased, i.e. a metallic electrical conductivity behavior.

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