| 초록 |
We have introduced 4'-(2-ethylhexyloxy)-3-ethynylbiphenyl or 4'-(2-ethylhexyloxy)-3-ethynyl-2,4-difluorobiphenyl as conjugated side chain substituents on benzodithiophene (BDT) unit to attain new BDT based electron rich units. An array of two donor-acceptor (D-A) polymers (P1, P2) based on new BDT moiety as electron rich unit and 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione unit as electron deficient entity were designed and synthesized. Here, we investigated the effect of fluorine atoms on the optical, electrochemical and photovoltaic properties of the polymers. The polymer P1 containing fluorine atoms in the side chain exhibited low bandgap (1.29 eV) when compared to the polymer P2 without fluorine atom (1.39 eV). As these polymers possess good thermal properties, film forming nature and very low bandgap, they appear to be interesting candidates for organic solar cell applications. |
