環境友善及水溶性之幾丁聚醣/氧化釔複合材料應用於可撓式全有機薄膜電晶體

Abstract

科學的進步給人類帶來許多方便，也帶來天然資源的枯竭。產品無論從製造過程到廢棄都會對環境造成嚴重的污染，因此無毒的材料和常溫的製程受到綠色科技產業的重視與發展。隨著生活需求增加，產業也致力發展建立在塑膠基板的可撓式有機電晶體。可撓式有機電晶體具有體積小以及可見光穿透性高的特性，主要可以應用在顯示器以及穿戴式元件。有機電晶體常由許多溶液製程步驟完成，這樣的製程有低溫以及大面積製造的優勢。因為需要使用對環境有傷害的溶劑並且可撓式有機電晶體的電性表現容易受到環境影響，故關於可撓式電晶體材料的選取以及製程都還有非常大的進步空間。本研究主要以無毒且可生物降解的生物性高分子幾丁聚醣作為主軸並以去離子水作為溶劑製成幾丁聚醣水溶液。以旋轉塗佈的方式製成幾丁聚醣薄膜並透過電容結構分析幾丁聚醣薄膜的電性。將高介電係數、無毒且生物相容性高的氧化釔奈米顆粒混合幾丁聚醣水溶液並且觀察氧化釔摻雜幾丁聚醣薄膜的介電性質和薄膜孔洞之改善。將幾丁聚醣摻雜氧化釔薄膜作為軟性有機電晶體之介電層並觀察摻入氧化釔對電晶體電性之增益。開關電流比值增加100倍以及漏電流的降低，同時幾丁聚醣薄膜具有電雙層效應可使得有機薄膜電晶體具有低壓操作的性質。本研究結果顯示，幾丁聚醣摻雜氧化釔薄膜做為有機薄膜電晶體的介電層不但具有無毒環保、低壓操作等特性，又因可撓式的特性，可以將此電晶體應用在不同曲率半徑的表面，例如：穿戴式電子產品，曲面電視等……

The advancement of science and technology has brought many conveniences for human beings along with the depletion of natural resources have also occurred. Because the manufacturing process and the wastes both cause the serious pollution to the environment, in this study non-toxic materials and room temperature process is focused on the development of the green technology industry. The industry is also committed to developing the flexible OTFTs on the plastic substrates with increasing the demands of living. The flexible OTFTs have several advantages such as high visible transmission and small size. The major applications of OTFTs are used as displays and wearable devices. The manufacture of OTFTs needs several solution processes which have the advantages of the large-area process and low-temperature process. Because the harmful solvent to the environment are often used in the solution process and the electrical performance of OTFTs are easily affected by the environment, the selection of materials and the process has very large room for improvement. The non-toxic and biodegradable biopolymer “chitosan” was the focus and the deionized water is used as a solvent to prepare an aqueous solution of chitosan. The chitosan thin films were formed by a spin coater and the electrical properties of the chitosan-based MIM structured capacitor were analyzed. The high-k-value, non-toxic, and biocompatible Y2O3 nanoparticles were blended into the chitosan solution and the improvement of the dielectric property and pinholes were observed by blending the Y2O3 nanoparticles. The thin films of chitosan blended with Y2O3 nanoparticles were used as the gate dielectric of the OTFTs and the enhancement of the OTFTs was observed by blending the Y2O3 nanoparticles. The on/off current ratio was one hundred times increased and the low leakage current was observed. Chitosan thin films have the electric-double-layers effect which makes OTFTs have the property of low-voltage operation. These results show that the blended chitosan/ Y2O3 thin films as the gate dielectric of the OTFTs have advantages of the non-toxic, environmentally friendly and low-voltage operation. These OTFTs can be used on the surface with different curvature radii such as wearable electronics and curved surface television because of the flexibility.