低溫化學合成複合介電材料於可撓式有機薄膜電晶體之應用

Abstract

近年來,隨著時間的進展奈米科技已成為目前各領域發展的熱門核心，不管是物理，化學，生物工程等等學門，奈米科技都是不可分割的一環，讓科技朝著更微觀的尺度進展。可撓曲式電子元件技術是目前各科技強國積極發展之領域，經由研究其材料基本特性，有系統地設計與製備可撓式電子產品將影響日常生活型態。本篇研究內容將針對各項可撓曲式電子元件進行探討，其中包括：金屬-絕緣層-金屬 (MIM)以及有機薄膜電晶體 (OTFT) 等。 本篇論文實驗，首先我們利用溶膠-凝膠 (sol-gel) 法配置配製附合介電材料，製程方法為混合聚苯乙烯(Polystyrene)與聚甲基丙烯酸甲酯(PMMA)以及P-123以甲苯(Toulene)為溶劑加入磁石攪拌反應12小時使溶質完全混合。旋轉塗佈混合完成的復合介電材料至金屬-絕緣層-金屬 (MIM)裝置上，作為介電層，利用4156 probe station量測其裝置之複合介電材料漏電流，量測結果最低漏電流密度值為4.95x10-10 A cm-2.經過連續測試此化合物有良好的穩定性，可置於室溫下近一個月並利用FTIR進行表面成分分析界定複合介電材料官能基，驗證所合成化合物之成分。利用接觸角量測儀實驗顯示，此介電材料為疏水表面，接觸角為86.86o且表面自由能約為20.8 mJ/m2。之後我們嘗試利用此複合介電材料薄膜當作絕緣層在PI基板上製作OTFT，實驗結果顯示其電性參數值, on-to-off current ratio: 1.5×105 ,mobility:0.041 cm2 V-1s-1.呈現良好的元件特性。

In recent years nanotechnology has become one of the most important and exciting forefront field in physics, chemistry, engineering and biology which the characteristic dimensions are below c.a. 1000 nm. Flexible technology is increasing its popularity in the electronic consumer product worldwide and it will make a great impact in all aspects of our everyday life, thanks to the fundamental breakthroughs in the way materials, science devices and systems are understood, designed and manufactured. In this thesis, the advances and prospects of nanotechnology in the fields of novel active and organic flexible thin films and organic-inorganic composite materials to be used for the production of flexible electronic devices, such as flexible metal-insulator-metal (MIM) capacitor, capacitors and organic thin-film transistor (OTFT), will be described. In the first part of the thesis is mainly about the discussion of the synthesis the hybrid dielectric material. A sol-gel solution was prepared by using 15 ml of toluene as solvent and blending different amount of pluronic 123, Poly-methyl methacrylate (PMMA), polystyrene. Under a magnetic stirring condition for 12 hr make the chemical perfectly mixed. Using MIM device using four-probe electrical measurement system to measure the leakage current is about 4.95x10-10 A cm-2.FTIR analysis is also used in the dielectric thin film analysis to confirm the synthesized material. Contact angle measurement reveals that the hybrid material is nearly hydrophobic, the contact angle is 81.87o, the surface energy of the hybrid dielectric material is 23.77 mJ/m2. Further, we successfully demonstrate OTFT device on flexible PI substrate by using hybrid dielectric material as insulator layer and P3HT as channel layer, the on-to-off current ratio of 1.5×105 and the mobility is 0.028 cm2 V-1s-1 even in the bending situation the device still shows great reliability and performance.