隨著全球能源需求的逐漸增加，以及現代氣候之驟變，開發新穎的汲取能源方式，且讓地球承受較低的負擔，是近代能源議題的發展方向，而熱電材料一直被視為具有潛力的能源轉換材料之一。熱電材料有多種的優點：熱能與電能之間是直接的轉換、由於為固態裝置且體積小，故易於行動、反應迅速且能量轉換具可逆性。過去數十年來的研究，低轉換效率限制了熱電材料的發展性，所以尋找更適合的材料，或優化現有材料以提升其熱電性質，是此領域當今主要的研究方向。
Bi-Te系列合金為低溫區段所普遍使用之熱電材料，本研究樣品以Bi0.5Sb1.5Te3（BST）合金為基材，分別運用液流加壓法、氣凝膠法，以及同時結合兩種加工法，有效的改變材料之熱電性質，使材料的熱電轉換效率有顯著的上升。根據文獻指出，以液流加壓法可以使超量的Te原子於晶界產生差排；而運用氣凝膠的手法，能夠使物質形成具有奈米級多孔洞的結構。上述兩種現象的產生，都是希望增加材料內聲子散射機制及降低聲子熱傳導(KL)，以達到提升ZT值的效果。
本研究欲探討在固定局部結構中，熱電性質與電子-軌域相互作用的關聯性、透過延伸X光吸收精細結構圖譜（EXAFS）研究局部原子/電子結構與熱電性質之間的相關性。我們的結果進一步顯示，在對BST進行不同的加工手法後，原子間的鍵長有所改變，且晶格排序程度也有所影響。

With the world’s growing energy needs and climate drastically changing, creating innovative ways to obtain energy by low influence burden to the earth is the development directions of the modern energy issue. Having been regarded as potential energy conversion materials, thermoelectric materials which move conveniently by small solid-state size convert energy directly, rapidly and reversibly between thermal and electrical energy. Decades of researching, the development of thermoelectric materials is limited with the low conversion efficiency, so looking for more suitable materials or optimizing the existing materials to enhance their thermoelectric properties is the main research direction in this field.
Bi-Te based alloy is the thermoelectric material that widely used within low temperature range, so we took Bi0.5Sb1.5Te3 (BST) as the substrate, applying the liquid flow method and aerogel method respectively and at the same time. Then we successfully changed the samples’ thermoelectric properties and increased the conversion efficiency significantly. According to the reference, the excess tellurium atoms on the grain boundary can be caused by liquid flow method; and nanoscale porous structure can be generated in materials by aerogel method. As mentioned above, those mechanisms are expected to increase the phonon scattering and to reduce the phonon thermal conductivity (KL), so that the ZT value can be enhanced.
In this study, we probed into the correlation between thermoelectric properties and electron-orbital interaction upon the fixed local structure symmetry. Correlations between local atomic/electronic structure and thermoelectric properties are investigated by Extended X-ray absorption fine structure spectrum (EXAFS). Our results show that the bond length between the atoms is changed and the lattice sequence is also affected by the different processing method for BST.

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