| 초록 |
There are various strategies for the high efficiency and better stability of polymer solar cells (PSCs). One of them is a control of the intermolecular arrangement and molecular packing using a non-covalent interaction by hydrogen bonds and Van der Waals forces. In this study, we designed and synthesized a novel small molecule 'IDTBTCf' with a polar molecule, caffeine, as an end-group. It was added as the 3rd composition of PTB7: PC71BM blend to make inverted solar cell. Especially, the PSCs with 2.5wt% ‘IDTBTCf’ achieved FFs of up to 68.6%, corresponding to PCEs of 8.4%, respectively. In the active layer, ‘IDTBTCf’ and D-A blend (PTB7:PC71BM) controls the molecular packing arrangement with non-covalent bonds interaction such as hydrogen bond, π-bonding, Van der Waals forces. As a result, ‘IDTBTCf’ makes better morphologies and it improves FF and shows good PCE and stability. |
