| 초록 |
Acceptor-donor-acceptor (A-D-A) type conjugated small molecules have been highlighted in organic photovoltaics (OPVs) due to highly rapid progress in the device performance. We designed and synthesized A-D-A type non-fullerene type acceptor materials, SP-PDN and SP-TCF, for high-performing OPVs. The SP-PDN and SP-TCF have an A-D-A structure consisting of 3D-shaped spirobifluorene donor core and PDN and TCF acceptor as terminal units. Two molecules showed similar 3D structure, optical and electrochemical properties, while their morphology in blend film with donor polymer, PTB7-Th, exhibited considerable difference. Especially, the SP-PDN : PTB7-Th blend film revealed obvious nanophase-separation, indicating that SP-PDN-based device showed relatively high PCE of 4.50% for SP-PDN. Additionally, we figured out the cause of different morphology and investigated consequent device performance with SP-PDN and SP-TCF by measuring surface energy of two molecules. |
