| 초록 |
In organic solar cells, Voc is one of the factors that determines efficiency. Voc effected by HOMO energy level. Deep HOMO energy level leads to High Voc value. To make deep HOMO energy level, many study are used electron withdrawing group. In this study, fluoro withdrawing group and cyano functional group were compared. The polymers,(PB-T-DCNPz, PB-T-DFPz) were synthesized by stile coupling reaction. All polymer dissolved in chloroform, chlorobenzene at elevated temperature. The absorption spectra measured in CB solution. And These polymer had maximum peak at 508nm ~ 580nm. In film state, maximum peak 711nm ~ 802nm. All polymers had red-shift at film state compare to solution state. The highest occupied molecular orbital (HOMO) energy of -5.51eV , -5.25eV (PB-T-DCNPz, PB-T-DFPz) was obtained by CV. In result, PB-T-DFPz showed increased PCE(%) of 4.14%. |
