| 摘要: | 當今傳統石化能源短缺和環境汙染問題重視，綠色能源開發為解決此問題一個重要技術途徑。熱電材料為一種利用半導體中電荷傳輸來實現熱能和電能間直接轉換，長期以來熱電材料都以無機半導體為主，但具有特殊結構無機半導體熱電材料資源有限且成本高、加工複雜且含重金屬具毒性等侷限而影響其大規模應用。近年來隨物聯網及可穿戴電子產品快速發展，對能利用溫度較低範圍之環境溫度梯度、體溫發電、長期免保養穩定性高的供應能量存在急切需求，這為熱電材料研究帶來新的機遇及挑戰。因此有機材料製備熱電元件對未來發展極為關鍵，其優勢在於低溫廢熱回收、具備分子設計調控性能、無毒性、成本低、可溶液製程及整合軟性基板及穿戴電式元件等，發展市場潛力將可提昇。本研究將設計一系列環境穩定性高且具有高遷移率的P型和N型有機半導體材料，選擇加入少量適當比例有機摻雜物、高熱電性質之無機半導體、奈米碳材或離子液體於有機載體中作為提昇熱電效能選擇。利用結構設計熱電材料、混摻行為、溶液製程、薄膜形貌及分子排列堆疊等對熱電效能最適化作深入探討。本計畫的亮點在於針對前四年計畫所研發有機熱電技術，於第五年整合製作原型產品-軟性熱電發電產生器模組及穿戴式體溫發電熱電元件。此外本計畫另一亮點在於運用機器學習技術識別有機半導體分子有利於電荷傳輸的化學分子結構和相關官能基集團，用以加速有機半導體分子和材料設計、合成、特徵和熱電應用性的前景。五年研究計畫目標如下：(1) 高電荷遷移率及高熱電效能有機半導體及其混摻材料開發。(2) 混摻系統及溶液製程參數對薄膜形態之控制並應用於熱電元件。(3)建立有機熱電材料中分子結構、溶液製程參數、混摻薄膜形態、半導體分子排列及元件效能關係。(4)有機熱電理論模型及人工智慧演算法識別有機半導體分子建立。(5)有機熱電原型產品開發。(6)開發溶液製程技術策略及材料用以未來整合新特性(結合光電、能源、電性、光學、磁性等)應用之尖端技術元件。 ;Green technology has attracted much attention in recent years due to the fear of exhaustion of traditional fossil sources and the rising awareness of environmental protection. Thermoelectric technology is an auxiliary energy technique that can directly convert waste heat to electricity. However, traditional inorganic thermoelectric materials meet significant challenges due to high cost (complex vacuum processing route), toxicity (element such as Pb, Bi and Te), scarcity (relatively low earth abundance), as well as brittleness particularly when it comes to applications requiring flexibility. On the other hand, organic materials possess some unique features like mechanical flexibility, wide-availability, solution processability in comparison to their inorganic counterpart. Furthermore, benefitting from striking developments in organic electronics, organic materials have been widely considered, with the unique features of fine-tuned electrical properties via molecular design. More importantly, organic materials offers potential for possessing high thermoelectric performance, which is capable to generate electricity from low temperature (<200 °C) heat sources. To achieve high performance of organic thermoelectric materials, doping organic semiconductors and composite materials will be prepared. In addition to optimizing the carrier concentration via doping process, thermoelectric materials through molecular structures such as backbones and side substitutes will be studied based on newly developed high mobility organic semiconductors. This is of great importance as both P- and N-type materials are required to fabricate an efficient thermoelectric generator. On the other hand, composites can possess organic characteristics such as solution-based processability and mechanical flexibility. Meanwhile fillers can control carrier transport to provide an alternative way of optimizing the tradeoff between the electrical and thermal properties. The carbon-based nanomaterials and inorganic semiconductors and ionic liquids can be candidates as fillers for synthesizing composites. Donor-acceptor conjugated polymers and small molecules with good semiconducting properties will be used for matrix. The chemical interactions between organic semiconductors and additives that will boost the thermoelectric properties and/or stability of the host material. The highlights of our proposal are two folds: First, the prototype thermoelectric device, flexible thermoelectric generator (TEG) and wearable thermoelectric for body heat harvesting, will be demonstrated based on the first four years research output. Second, the use of machine learning models taking in input information regarding the similarity of organic semiconductors in terms of chemical topology and electronic structures will be performed, which can automatically screen the prospective organic semiconductors for their theoretical mobility. The list of top candidates in organic thermoelectric materials was then whittled down based on chemical intuition about what can be synthesized in practice. In the five-year proposed project, the following issues will be addressed: (1) Development of high mobility in organic semiconductors. (2) Solution-processing parameters and composites for manipulating film morphologies and thermoelectric properties. (3) Establish the relationship between molecular design, mixing behavior, film morphologies and molecular packing of semiconducting domains and device performance. (4) Theoretical investigation on the organic thermoelectric materials and machine learning for organic semiconductors. (5) Organic thermoelectric prototype product. (6) Develop the solution processing technology for future organic device application including the field of optoelectronic, energy, electronics, optics and magnetic, etc. |
