由於熱電模組轉換效率與材料理想效率出現落差，本計畫旨在研究薄膜熱電材料金屬電極與擴散阻障層之材料選擇，並評估模組前後對熱電性質影響，從材料界面角度探討其與熱電性質關係，建立有效模組效能評估模型。計畫將分三年，逐年針對三種常見熱電材料：低溫鉍碲(Bi2Te3)、中溫鉛碲(PbTe)與方鈷礦(Skutterudite, CoSb3)熱電材料分別進行，預計採用共濺鍍法製備精確化學比熱電薄膜。第一年計畫將探討低溫Bi2Te3薄膜與常用金屬墊層間界面反應，並比較空片與模組化試片，於長時間熱處理下微結構對熱電性質影響，同時評估不同金屬擴散阻障層對於Bi2Te3熱電模組帶來之必要性。計畫第二年針對中溫段熱電表現較佳之PbTe熱電薄膜，進行模組熱電性質影響分析。相較於低溫模組，溫度造成接面交互擴散與介金屬化合物生成將更顯著，因此將深入探討界面處微結構及熱電表現變化。第三年選用近年新興之中溫CoSb3，此材料具特殊方鈷礦結構且環境友善性佳，此年將以前兩年研究經驗出發，作為薄膜熱電模組之未來前瞻與可行性研究。本計畫希望從材料冶金性質、物理性質及機械性質等角度出發，了解界面特性對熱電模組所帶來之影響，從實驗數據建立有效評估數學模型，以改善未來薄膜熱電模組效率，期望能對現今各國高度重視能源議題提供重要資訊。 ;The researches on thermoelectric materials mainly focuses on the thermoelectric properties of the materials. There is a decrease of thermoelectric efficiency when the materials are packaged to modules. The differences in the efficiency are caused by the junctions or the interfaces between the thermoelectric materials, the electrodes and even the diffusion barriers. This proposal will study the thermoelectric efficiency of the modules from the materials perspective. In the first year, low temperature Bi2Te3 and its junctions with the electrodes and the diffusion barriers will be investigated in detail. The interdiffusion and the growth of intermetallic compound will be more prominent when the working temperature is raised. In the second and the third year, the junctions between mid-temperature PbTe and CoSb3 will be studied, respectively. The results of this project can provide detail understanding of materials selection for the modules. The knowledge can benefit both the academic and industrial society to further improve the thermoelectric efficiency.
