有機電化學電晶體 (OECTs) 是一種非勻相的半導體元件。因為其將離子信號轉換為電信號的能力，且具有低功耗和靈活性，成為生醫感測器和仿生神經突觸的理想選擇，尤其適合用於可穿戴和植入式醫療設備。OECT元件的性能直接與聚合物通道層的導電性和離子導電性相關。然而這些性能通常存在相互抑制的關係，因此需要對聚合物材料進行系統設計以優化設備性能。在現有的研究中，提升OECT的性能已成為研究人員的主要目標。通過引入親水性側支鏈 (寡聚醚) 和疏水性側支鏈 (枝狀烷基) 至主鏈為異靛藍-雙噻吩 (isoindigo-bithiophene) 的聚合物中，進而了解高分子層的親水性質對離子的摻雜與滲透優化對於元件性能的提升。另外比較對稱性和非對稱側支鏈組合，探討聚合物的共面性、電子遷移率和穩定性對於元件性能的影響。對稱側支鏈設計如 P(C,C) 和 P(O,O) 展現不錯的參數，但非對稱側支鏈設計 P(C,O) 的表現則更為優異。作為應用於OECT這種非勻相的半導體元件的高分子，非對稱側鏈設計 P(C,O) 展示了優越的OECT性能，其電洞遷移率與電容的乘積 (μhC* = 65.16 F cm−1 V−1 s−1)，電洞遷移率 (μh = 0.78 cm² V−1 s−1)，以及快速的響應速度 (tr = 5.41 s, tf = 0.035 s)。另外聚焦在元件穩定性上，P(C,O)在保持良好電容的同時展示了卓越的薄膜穩定性，可以在OECT反覆運行下維持良好的膜況，電流的維持率 (ID retention) 為 77.5%。使用異靛藍-雙噻吩作為主鏈高分子，並結合親水性側支鏈與疏水性側支鏈，非對稱組合的高分子擁有優異的共面性和性能。引入寡聚醚側支鏈還賦予較好的親水性，提高離子滲透性。非對稱結構有助於增強共面性和結構穩定性，從而在薄膜澎潤後改善結晶性能。在我的研究中給出了一種在OECT元件上，通過非對稱側支鏈設計同時實現高電洞遷移率和元件穩定性的平衡方法，進而為未來的高性能OECT設計提供參考。

Organic electrochemical transistors (OECTs) have become ideal choices for biosensors and artificial synapses due to their ability to convert ion signals into electrical signals, as well as their low power consumption and application flexibility. These attributes make OECTs particularly suitable for wearable and implantable bio-medical devices. The performance of OECT devices is directly related to the conductive and ion-conductive properties of the polymer channel layer. However, these properties often exhibit a mutually inhibitory relationship, necessitating a systematic design of polymer materials to optimize device performance. Enhancing the performance of OECTs has been a primary goal in recent research. By introducing hydrophilic and hydrophobic side chains into poly(isoindigo-bithiophene)-based (PII2T) polymers and comparing symmetric and asymmetric side chain combinations, improvements in coplanarity, mobility, hydrophilicity, and stability can be achieved. While symmetric side chain designs, such as P(C,C) and P(O,O), have demonstrated certain device parameters like mobility and capacitance, the asymmetric side chain design P(C,O) has shown superior performance. Specifically, the asymmetric side chain design P(C,O) exhibited outstanding OECT performance, with a product of mobility and capacitance (μhC* = 65.16 F cm−1 V−1 s−1), excellent hole mobility (0.78 cm² V−1 s−1), and fast response speed (tr = 5.41 s, tf = 0.035 s). Additionally, P(C,O) showed superior stability while maintaining good capacitance, with a charge retention (ID retention) of 77.5%. Using PII2T as the backbone and combining it with branched alkyl and oligoether side chains resulted in a polymer with an asymmetric combination that exhibited excellent coplanarity and performance. The incorporation of oligoether side chains also imparted strong hydrophilicity, facilitating high ion permeability. The asymmetric structure contributed to enhanced coplanarity and structural stability, resulting in improved crystalline properties after swelling. This study presents a balanced approach to achieving both high mobility and stability in OECTs through asymmetric side chain design, aiming to provide a reference for future high-performance OECT designs.

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