本研究利用溶液製程並透過剪切力塗佈法製作有機薄膜電晶體元件，主要研究於有機薄膜層，由於之前實驗室製作含硫碳鏈之p-type有機小分子材料SBT，有機薄膜元件電性達1.7 cm2V-1s-1。本研究將硒取代硫原子運用不同鍊長的含硒碳鏈之聯噻吩(selenylated bithiophene; SeBT)為核心，核心頭尾兩端接上三併環噻吩(2,6-di(dithieno[3,2-b;2’,3’-d]-thiophen-2yl; DDTT）為主軸，合成本研究使用得P-type有機小分子半導體材料DDTT-SeBT-C6、DDTT-SeBT-C10及DDTT-SeBT-C14。 隨著含硒碳鏈長的增加，載子遷移率從DDTT-SeBT-C6 0.09 cm2V-1s-1，增加至DDTT-SeBT-C10 0.06 cm2V-1s-1，再增加至DDTT-SeBT-C14 4.01 cm2V-1s-1，並利用光學顯微鏡、原子力顯微鏡等儀器分析其表面形貌。其中，DDTT-SeBT-C6薄膜呈現不連續狀，DDTT-SeBT-C10從GIXRD可發現結晶性不佳，所以造成電性不佳，反之，DDTT-SeBT-C14表面形貌呈現連續性且結晶性佳，得到優異的電性表現載子遷移率4.01 cm2V-1s-1，我們利用單晶可知，當側鍊較長時，可改善主軸扭轉角使分子呈平面性提高載子遷移率。 ;This study research new small molecule semiconductors via solution shearing manufacture organic thin film transistors. Owing to the previous work thio-alkyl substituted bithiophene (SBT), the organic thin film transistor electrical properties is 1.7 cm2V-1s-1. The series of new small molecules is selenylated bithiophene with different alkyl side chains. Then, add 2,6-di(dithieno[3,2-b;2’,3’-d]-thiophen-2yl (DDTT) to become the main backbone on the both side of the core. As the carbon length increase, the carrier mobility increases from DDTT-SeBT-C6 0.09 cm2V-1s-1 to DDTT-SeBT-C14 4.01 cm2V-1s-1. The surface morphology was analyzed by optical microscopy, atomic force microscopy, grazing incidence x-ray diffraction, UV-vis spectrophotometer. In these three molecules, the morphology of DDTT-SeBT-C6 is discontinuity. The crystallinity of DDTT-SeBT-C10 is worse. That the reason why they get the poor electrical properties. However, the morphology of DDTT-SeBT-C14 is continuity and the high crystallinity. When the side length increase, the torsion angle can be improved to make the backbone planar to improve the carrier mobility.
