| 초록 |
Low photovoltaic conversion efficiency is the problem of organic solar cells, and a number of research had been conducted to increase its efficiency. In this study, HOMO was controlled by using CN groups and F groups as withdrawing groups in the polymer. We compared PBDT-CNPz and PBDT-FPz which were synthesized for sille coupling. In this experiment, we expected that PBDT-CNPz would have a higher Voc than PBDT-FPz due to the lower HOMO. As a result, the HOMO of PBDT-CNPz was -5.51 eV, which was 0.26 eV lower than that of PBDT-FPz having -5.25 eV. The Voc of PBDT-CNPz was 0.74V, which was 0.07V higher than that of PBDT-FPz of 0.67V. However, it showed a PCE of 2.02% due to a low Jsc of 7.08mA/cm2 and a low FF of 0.39. The PCE of PBDT-FPz was 4.14%, which was 2.12% higher than that of PBDT-CNPz. However, the withdrawing group of PBDT-dCNPz is strong and the HOMO value is deeper at 0.26 eV, indicating the possibility that PBDT-dCNPz will be used as a acceptor rather than a donor. |
