| 초록 |
We synthesized a series of small molecules based on 7,7′-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene-2,6-diyl)bis(4-(5′-hexyl-[2,2′-bithiophene]-5yl)benzo[c][1,2,5]thiadiazole) (DTS(BTTh2)2) with different number of fluorine substitution (0F-4F). Depending on the numbers of fluorine atoms incorporated in the benzo[c][1,2,5]thiadiazole (BT) unit, we investigated how different numbers of fluorine on the BT unit and the molecular symmetricity influenced the optical and morphological properties in solid state. In the bulk heterojunction solar cell fabricated with PC71BM, 2F achieved the highest power conversion efficiency (PCE) with an 8.14% and 0F shows the lowest PCE of 1.28%. In our studies, the solid state intermolecular interaction varied by introducing substitution group affect the molecular conformation which could be essential factor in development of high performance organic semiconducting materials. |
