| 초록 |
Following the synthesis of two novel fluorinated analogues of TQ, namely TQ-F and TQ-FF, both their experimental results and theoretical calculations can allow us to further uncover the underlying working principles of F atoms on each of the three photovoltaic parameters. The resulting two fluorinated polymers show a decrease in both the HOMO and the LUMO energy levels relative to non-fluorinated TQ. Moreover, the fluorination of the polymer backbone has lowered the HOMOs more than the LUMOs, slightly widening the energy bandgaps as the number of F atoms increases. Thus, use of these polymers in bulk-heterojunction (BHJ) solar cells, in all cases, leads large VOC values. The power conversion efficiency (PCE) of the optimized PSCs based on TQ-F reaches 4.41%. In addition, it is interesting to note that, despite TQ-FF having the PCE that is lower than TQ-F, an unprecedentedly high VOC of 1.00 V is achieved, which is nearly equaled the highest VOC values ever reported for polymers. |
