聚(3-己烷噻吩)摻雜石墨烯奈米結構之有機薄膜場效電晶體

Abstract

科技始終來自於人性，消費者對資訊產品便利性以及易攜帶的需求日益提高，相對的其商品同時也不斷的推陳出新，開發軟性電子元件就逐漸成了學者研究的目標。可撓式電子元件只需溶液旋轉塗佈（Spin Coating）或噴墨印刷（Ink-jet Printing）等造價較為低廉的製程技術即可將微電子元件製作於軟性基材上，使製程成本大幅度下降。近年來因有機材料受到關注，同時也讓許多大廠紛紛投入研發。導致一部分原本使用無機材料所製作的電子產品逐漸使用有機材料來製作以達到可撓曲的效果，例如可撓式顯示器、太陽能電池、電子紙及RFID標籤等，其中有機薄膜電晶體更是於顯示器的背板有廣泛的應用。 有機材料其電性表現往往不如無機材料，只能被應用於較低階的電子產品，但因常使用溶液製程，具有成本低以及低溫製程的優勢，而受到學者們持續性的投入開發，為了將來能夠和無機材料與之匹敵，提升有機材料之載子遷移路率及元件穩定度則是今後最大的課題。 本論文主要為探討兩個部分為主，第一部分為提升有機半導體載子遷移率，我們選用石墨烯奈米結構摻雜有機半導體形成混合式有機半導體層，最後製作成有機薄膜電晶體以提升其載子遷移率，在不影響P3HT晶格排列下找出其摻雜石墨烯奈米結構之最大濃度，應用石墨烯優良的導電性，提升元件整體電性表現。摻雜結果發現當摻雜比例為1wt%時有最佳的電性表現，其載子遷移率提升了10倍之多(0.00626→0.0619 cm2/VS)。第二部分為有機半導體之元件生命週期探討，本實驗應用石墨烯薄膜作為阻擋層轉移覆蓋於有機薄膜電晶體表面，目的為隔絕環境中之氣體分子與水分子期望能延續元件之操作壽命。在大氣環境下，透過量測元件做電性追蹤可發現，未應用石墨烯薄膜阻擋層之有機薄膜電晶體元件其壽命在10天左右時就失去電晶體特性，而運用石墨烯薄膜作為阻擋層之有機薄膜電晶體元件其壽命在57天後才逐漸失去電晶體特性，我們發現加入石墨烯薄膜阻擋層後能有效阻絕水氧破壞有機半導體，增加其元件壽命達47天之久。

Technology has always come from human nature. In recent years, information terminal devices have become more convenient and easily portable to meet customers’ needs. This desire and request gradually stimulates the development of flexible electronics. Conventional electronic components use silicon wafers or glass as the substrate material and are fabricated using expensive lithography processes, while flexible electronics use either Spin-Coating or Ink- -jet Printing) and other process technology. Microelectronic components are manufactured on flexible substrates, which significantly reduce the cost of traditional semiconductor processes and make organic materials attract attention in recent years. Many manufacturers have also invested in research and development. Electronic products made of inorganic materials in the past are replaced by organic materials were many advantages, also developed many products. For example, electronic paper, flexible display, OTFT, and RFID tags. In the fabrication process of organic devices, solution based process were adopted in this study, which have advantages such as low cost and low process temperature. However, the electrical properties of organic thin film transistors(OTFT) are usually poor compare with thin-film transistor made of inorganic materials. The performance improvement on OTFT is therefore an important research issue and will be investigated in this thesis. This study utilized graphene nanostructures a mobility enhancer for organic thin film transistors. The loading of graphene plays a crucial role in transistor performance. In our research, when we hybrid 1wt% graphene nanostructures in P3HT. A ten-fold enhancement in device mobility(0.00626→0.0619 cm2/Vs) has been successfully achieved. The second is to employ graphene as barrier films layer covering the surface of OTFTs. The purpose is to isolate the gas molecules and water molecules in the environment in order to extend the operational life of the components. In the atmospheric environment, through the measurement of electrical components can be found organic thin-film transistor devices without a graphene film barrier have lost their transistor characteristics over a 10 days, and the use of graphene film as a barrier layer of the organic thin film transistor components in the life of 57 days to gradually lose the transistor characteristics. It can be found that adding a barrier layer of graphene film can effectively block the destruction of organic semiconductors by water and oxygen, increasing the component life of up to 47 days.