Abstract
Nonfullerene acceptors propelled organic solar cell power conversion efficiencies (PCE) to above 15%. However, most of the reported nonfullerene systems with a PCE > 10% are composed of polymer donors and small-molecule acceptors, while only a few small molecule (SM) donors have been reported. Herein, two new small molecule donors namely BDT-RO and BDT-RN with esterified rhodanine (ER) as the terminal group are reported. The widely used fused-ring acceptor IDIC is chosen to fabricate all-small-molecule solar cells with the new donors. A high PCE of over 9.0% is achieved with BDT-RO, while its isomer BDT-RN shows a PCE close to 8.4%. Comparison with the common small molecule donor DR3TBDTT using the same conditions yielded lower performance (7.6% with IDIC), indicating an 18% enhancement in PCE could be achieved through end group engineering. The efficiency differences are attributed to the different morphology and phase separation resulting from the crystallinity and aggregation ability of the donors. The results demonstrate that ER is a promising building block when designing SM donors for all-small-molecule systems.
Original language | English (US) |
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Pages (from-to) | 2541-2546 |
Number of pages | 6 |
Journal | Journal of Materials Chemistry A |
Volume | 7 |
Issue number | 6 |
DOIs | |
State | Published - 2019 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: This work was financially supported by the National Natural Science Foundation of China (No. 61805245 and No. 21702202), CAS Pioneer Hundred Talents Program (Y82A060Q10), Recruitment Program of Global Experts (R52A199Z10), Youth Innovation Fund (Y82Z330Q10) and Natural Science Foundation of Chongqing (cstc2015jcyjB0628 and cstc2017rgzn-zdyfX0030). The research reported in this publication was also supported by funding from the King Abdullah University of Science and Technology (KAUST). Tainan Duan and Hua Tang contributed equally to this work.