本研究以氧化鋅(ZnO)/富矽氧化物(Silicon-rich oxide,SRO)多層結構熱電材料為主軸，分為模擬與實驗兩部分，研究目的為最佳化薄膜厚度和利用富矽氧化層，進行聲子散射以降低熱導率，進而提升氧化鋅材料的ZTM值。
模擬使用Lammps這套軟體，以分子動力學模擬氧化鋅、矽、氧化鋅/矽多層結構統的熱導率，此部分又分為模型的建構與熱導率計算兩小節探討。模型建構主要是探討原子間勢函數和系綜的選擇，勢函數關係到原子間鍵結的力場大小、角度等等情況，系綜則是選擇在適合的環境下進行模擬計算。熱導率分為不同種類的計算方式，選擇類似實驗的計算方式，有助於計算結果上更接近實驗值。選擇了適合的勢函數、系綜、熱導率計算方式，就能計算出不同厚度、層數的熱導率，結果發現厚度越薄的薄膜有較低的熱導率值，而分層結構的熱導率也比單層薄膜低，可達到個位數值，此預測的結果對應在實驗的ZTM值。
實驗利用濺鍍製作氧化鋅/富矽氧化物的多層膜，此部分分為成分分析與電性量測探討。成分分析部分，我們藉由穿透式電子顯微鏡或是掃瞄式電子顯微鏡觀察薄膜的奈米結構，利用X光繞射儀計算晶粒大小，發現多層結構或是厚度較薄的薄膜具有較小的晶粒，因此可以利用厚度控制晶粒尺寸;而晶粒越小的薄膜通常擁有較低的熱導率，因此可以用膜厚調整熱電性質。電性量測利用Harman method量測計算出ZTM，發現多層膜的ZTM擁有比較好的表現，印證聲子散射對於ZTM的提升有明顯的影響，相較於文獻單層的ZnO薄膜，其熱電優質可以提升3倍左右，ZTM可達到0.32。
除了多層結構對於聲子散射的提升以外，我們也希望探討電導率對ZTM的影響，因此本研究使用氧化鋅鋁(Al-doped Zinc Oxide, AZO, 2%)取代前述多層結構中的ZnO，製作氧化鋅鋁/富矽氧化物的多層結構，發現ZTM也同樣有所成長，相較於文獻單層的AZO薄膜，其熱電優質也可以提升倍左右，ZTM可達到0.48，這樣的結果使得氧化鋅的熱電材料大大的增加了應用的可能性。

In our research, zinc oxide (ZnO) / silicon oxide (silicon oxide) (SRO) multilayers were anylized by simulation and expertiment. We optimize the film thickness and use the silicon-rich oxide layer as phonon scattering to reduce the thermal conductivity.Therefore, it can enhance the ZTM of the zinc oxide material.

The thermal conductivity of zinc oxide, silicon oxide, zinc oxide / silicon multilayer structure was simulated by MD simulation. This part was divided into two sections: model construction and thermal conductivity calculation.In the model construction, it is important to choose potential and ensemble.The potential is the force field and angle of inter-atoms.The ensemble is to choose which condition you want to simulate.In thermal conductivity calculation, there are many different methods to calculate thermal conductivity and we have to try which one is the best to approach our experimental result.
In the simulated result, the thermal conductivity of model is according to its thickness .The thermal conductivity of ZnO/Si multilayer are lower than ZnO or Si. It can reach down to digits.These simulated results corresponds to the ZTM value in the experiment.

The ZnO/SRO multilayers were prepared by sputtering. According to our results, there is smaller grain size in thinner film. Thermal conductivity is affected by grain size. Therefore, we can control the thickness of film to optimize the ZTM of ZnO/SRO multilayers.In comparsion of ZnO/SRO multilayers produced in this work with ZnO published in the literature, the ZTM of former is 0.32 and it is three times higher than the latter. The AZO/SRO multilayers were also prepared by sputtering because we want to enhance electrical conductivity of ZnO/SRO multilayers .Moreover, the ZTM of AZO/SRO multilayers is up to 0.48.As the result of our research, the ZnO is possible to apply to the thermoelectric device.

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