| 초록 |
We successfully synthesized series of polymers ,PB-DBPCN, PB-DPQCN, and PB_BtCN with typical D-A structure for photovoltaic applications using the stille polymerization. Benzodithiophene (BDT) is used for electron donor, while dibenzophenazine (DBPZ), diphenylquinoxaline (DPQx), or benzothiadiazole (BT) as the electron acceptor. The cyano group which is withdrawing substituents was incorprated into the electron acceptor in polymers to reduce the bandgap and highest occupied molecular orbital (HOMO) The lowlying HOMO energy level and reduced bandgap are strongly correlated with the improved open circuit voltage (Voc) and short circuit current (Jsc), respectgively. Bulk-heterojunction polymers were fabricated with an inverted devices of ITO/ZnO/active layer (polymer:PC71BM)/MoO3/Ag. The best conversion efficiency (PCE) of 4.59% was obtained from a device based on PB_BtCN. |
