| 摘要: | 以接上側鏈增加溶解度之四併環噻吩(3,7-dipentadecyltetrathienoacene；TTAR)為核心並在兩側接上三種不同數目併環噻吩構成之次結構: (1) 2,6-di(thiophen-2yl) DT、(2) 2,6-di(thieno[3,2-b]- thiophen-2yl) DTT，(3) 2,6-di(dithieno[3,2-b;2’,3’-d]thiophen-2yl) DDTT，來合成實驗中使用的TTAR系列p型有機小分子半導體材料(DT-TTAR、DTT-TTAR、DDTT-TTAR)。
透過剪切力塗佈之溶液製程，由TTAR系列製成之場效應電晶體隨著次結構上併環噻吩數目增加，其載子遷移率從DT-TTAR的0.03 cm2V-1s-1，增加至DTT-TTAR的0.13 cm2V-1s-1和DDTT-TTAR的0.81 cm2V-1s-1；從UV-vis吸收光譜、AFM表面形貌分析與低掠角X光繞射對有機半導體薄膜之分析，可以觀察到透過增加併環噻吩數量之次結構，使得TTAR系列有著更明顯的分子間硫-硫(S-S)作用力使得分子形成更有序之排列，降低分子內TTAR核心與次結構之間不共平面所造成之影響，形成更有序之分子排列；TTAR系列小分子隨著結構上併環噻吩數量增加，由電性量測得到載子遷移率增加之結果可以觀察到透過改變TTAR核心連接之不同次結構，能夠增強分子間作用力，並對載子遷移率的增加有著正面的影響。
;New synthesis organic semiconductor (OSC) materials with the core of 3,7-dipentadecyltetrathienoacene (TTAR , R = C15H29) combining with three different thiophene-based end-capping groups on both side of TTAR core. These substructures are: (1) 2,6-di(thiophen-2yl) DT, (2) 2,6-di(thieno[3,2-b]- thiophen-2yl) DTT, (3) 2,6-di(dithieno[3,2-b;2’,3’-d]thiophen-2yl) DDTT. Combining with these substructures and TTAR core to form the p-type OSC materials (DT-TTAR, DTT-TTAR and DDTT-TTAR) for organic filed effect transistor (OFET) application.
By solution shearing process, the mobility of TTAR series OFET increases from 0.03 cm2V-1s-1 (DT-TTAR) to 0.81 cm2V-1s-1 (DDTT-TTAR) with the same trend of increasing number of fused thieophene end-capping groups. With the result analysis from UV-vis absorption spectroscopy, AFM topography and graze incident x-ray diffraction (GIXRD). We can observe the bathochromic shift on UV-vis spectroscopy resulted from stronger intermolecular interaction which is caused by increasing number of fused thiophene end-capping groups by. AFM topography shows that larger domain size with the same trend of increasing number of fused thiophene end-capping group on the both sides of TTAR core. On the analysis result of GIXRD, the azimuthal swing of (0,0,2) diffraction peak reduced by stronger intermolecular interaction induced by end-capping groups. With the aid of stronger intermolecular interaction, the reduction of azimuthal swing shows that more uniform molecular packing along with the qz direction. By the analysis results of UV-vis spectroscopy, AFM topography and GIXRD, the increasing number of fused thiophene end-capping groups provide stronger intermolecular interaction to reduce the effect of non-coplanarity between the TTAR core and end-capping groups. The results show that increasing number of fused thiophene end-capping groups have positive effect on higher charge carrier mobility and more order molecular packing. |
