| 초록 |
The new alternating copolymers (PBDT-DT-DFQx and PBDT-DT-FQx) were synthesized via Stille coupling reaction using Pd as a catalyst. To look into the influence of fluorine atom, either di- or mono-fluorinated quinoxaline (Qx) unit was introduced to the resulting copolymers. Qx unit was used due to the advantage of solubility of the polymers. The Qx unit could introduce the alkyl groups on the top of the structure, which leads to better solution processability. Thieophene bridge was used to play a huge role as molecular spacer on the conjugated backbone in the polymers. These polymers showed an optical bandgap of 1.97–2.00eV, with lowest unoccupied molecular orbital (LUMO) energy around -3.54eV. In these polymers, Strong absorption was displayed in the range of 400-650nm in film state. Consequently, High 5.58% of power conversion efficiency (PCE) was achieved with PBDT-DT-DFQx. |
