| Institution: | 1. Engineering Research Center for Nanomaterials, Henan University, Kaifeng, 475004 China
These authors contributed equally to this work.;2. National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, 210093 China;3. State Key Laboratory for Modification of Chemical Fibers and Polymer Material, Center for Advanced Low-Dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620 China;4. Engineering Research Center for Nanomaterials, Henan University, Kaifeng, 475004 China;5. National Center for Nanoscience and Technology, Beijing, 100190 China;6. Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing, 100875 China |
| Abstract: | Non-fullerene acceptors have shown great promise for organic solar cells (OSCs). However, challenges in achieving high efficiency molecular system with conformational unicity and effective molecular stacking remain. In this study, we present a new design of non-fused tetrathiophene acceptor R4T-1 via employing the encapsulation of tetrathiophene with macrocyclic ring. The single crystal structure analysis reveals that cyclic alkyl side chains can perfectly encapsulate the central part of molecule and generate a conformational stable and planar molecular backbone. Whereas, the control 4T-5 without the encapsulation restriction displays cis- and twisted conformation. As a result, R4T-1 based OSCs achieved an outstanding power conversion efficiency (PCE) exceeding 15.10 % with a high short-circuit current density (Jsc) of 25.48 mA/cm2, which is significantly improved by ≈30 % in relative to that of the control. Our findings demonstrate that the macrocyclic encapsulation strategy could assist fully non-fused electron acceptors (FNEAs) to achieve a high photovoltaic performance and pave a new way for FNEAs design. |
