| 초록 |
Polymer solar cells (PSCs) have been investigated intensively caused by their advantages. However, the research still has a room to improve the low efficiency and stability.1-2 We designed polymers containing electron-deficient units, 2-pyriminecarbonitrile and 2-fluoropyrimidine, and used for the photovoltaics. We synthesized the new conjugated polymers, PTTICN, PTTICNR and PTTIFR, which were synthesized by Stille polymerization. The optical band gaps from UV-vis absorption onset of PTTICN, PTTICNR and PTTIFR were about 2.0 eV. The HOMO energy levels of four polymers (PTTICN, PTTICNR and PTTIFR) were at -5.26 ~ -5.34 eV, their LUMO energy levels were at -3.47 ~ -3.50 eV, corresponding to the electrochemical band gap of around 1.8 eV. The device comprising PTTICNR and PC71BM (1:4) with DIO showed a VOC of 0.82 V, a JSC of 6.38 mA/cm2, and a fill factor (FF) of 0.54, giving a power conversion efficiency of 2.81%. |
