In recent years,power conversion efficiency(PCE)of organic solar cells(OSCs)has made significant improvement.A large number of studies were reported to achieve high PCEs through exploring new active layer materials,es...In recent years,power conversion efficiency(PCE)of organic solar cells(OSCs)has made significant improvement.A large number of studies were reported to achieve high PCEs through exploring new active layer materials,especially the high efficiency fused ring acceptors(FRAs).Compared with FRAs,another type of so-called unfused-ring acceptors(UFAs),possessing some advantages such as simple synthesis and low cost,have attracted a lot of attention.Herein,a new UFA BTzO-4F,incorporating with a benzotriazole moiety and S···O intramolecular noncovalent interactions,has been successfully synthesized.The photovoltaic device based on PBDB-T:BTzO-4F achieved a record PCE of 13.8%for UFAs,which indicates that introducing the benzotriazole moiety is an effective strategy for high quality acceptors.Thus,these findings of this work demonstrate the great potential of UFAs for high performance OSCs.展开更多
Two simple electron acceptors based on unfused bithiophene core and 1,1-dicyanomethylene-3-indanone end group were easily prepared via three synthetic steps. These acceptors exhibited broad absorption in the range of ...Two simple electron acceptors based on unfused bithiophene core and 1,1-dicyanomethylene-3-indanone end group were easily prepared via three synthetic steps. These acceptors exhibited broad absorption in the range of 300 nm to 800 nm, aligned energy levels and high crystallinity. When combined with a wide band gap donor polymer in non-fullerene solar cells, an initial power conversion efficiency of 2.4% was achieved. The relatively low efficiencies were due to the large phase separation in blended thin films, which is originated from their high aggregation tendency in thin films. Our results suggest that these electron acceptors with unfused core are promising candidates for commercial application of solar cells due to the low cost starting materials and facile synthesis.展开更多
In recent years, non-fullerene acceptors(NFAs) with unfused-ring structure have received extensive attention due to their flexible combination of building blocks and relatively simple synthetic routes. In this work, t...In recent years, non-fullerene acceptors(NFAs) with unfused-ring structure have received extensive attention due to their flexible combination of building blocks and relatively simple synthetic routes. In this work, three new A-D-C-D-A type unfused-ring acceptors(UFAs),named DTBTz EH-IC2F, DTBTz Me-IC2F and DTBTz Me-IC2Cl, were designed and synthesized with dithienobenzotriazole(DTBTz) as the core.Through modification of alkyl chain on the DTBTz unit and change of halogen atoms on the cyanoindanone end groups, the differences in optoelectronic properties of these three small molecule acceptors were investigated. The results show that changes in alkyl chain and halogen atom endow UFAs with different features, including shift in absorption, changes in energy level and molecular packing. When blended with donor PBDB-T, the organic solar cell based on DTBTz Me-IC2Cl achieves the highest device efficiency of 12.3%, while DTBTz EH-IC2F-based device obtains 11.5% efficiency and DTBTz Me-IC2F-based device obtains 12.0% efficiency. The stability tests show that all the devices obtain good efficiency retention rates. These results demonstrate that the introduction of a rigid aromatic ring DTBTz as an intermediate core not only effectively results in highly planar A-D-C-D-A small molecules, but also provides a new reference for the design and development of UFAs in OSCs.展开更多
基金the National Natural Science Foundation of China(21774130,51925306)the National Key R&D Program of China(2018FYA 0305800)+4 种基金the Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-JSC046)Key Research Program of the Chinese Academy of Sciences(XDPB08-2)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB28000000)the International Partnership Program of Chinese Academy of Sciences(211211KYSB20170014)China Postdoctoral Science Foundation(2020M670425)。
文摘In recent years,power conversion efficiency(PCE)of organic solar cells(OSCs)has made significant improvement.A large number of studies were reported to achieve high PCEs through exploring new active layer materials,especially the high efficiency fused ring acceptors(FRAs).Compared with FRAs,another type of so-called unfused-ring acceptors(UFAs),possessing some advantages such as simple synthesis and low cost,have attracted a lot of attention.Herein,a new UFA BTzO-4F,incorporating with a benzotriazole moiety and S···O intramolecular noncovalent interactions,has been successfully synthesized.The photovoltaic device based on PBDB-T:BTzO-4F achieved a record PCE of 13.8%for UFAs,which indicates that introducing the benzotriazole moiety is an effective strategy for high quality acceptors.Thus,these findings of this work demonstrate the great potential of UFAs for high performance OSCs.
基金supported by MOST (No. 2017YFA0204702)National Natural Science Foundation of China (Nos. 51773207, 21574138, 51603209, 91633301)supported by the Strategic Priority Research Program (No. XDB12030200) of the Chinese Academy of Sciences and the Recruitment Program of Global Youth Experts of China
文摘Two simple electron acceptors based on unfused bithiophene core and 1,1-dicyanomethylene-3-indanone end group were easily prepared via three synthetic steps. These acceptors exhibited broad absorption in the range of 300 nm to 800 nm, aligned energy levels and high crystallinity. When combined with a wide band gap donor polymer in non-fullerene solar cells, an initial power conversion efficiency of 2.4% was achieved. The relatively low efficiencies were due to the large phase separation in blended thin films, which is originated from their high aggregation tendency in thin films. Our results suggest that these electron acceptors with unfused core are promising candidates for commercial application of solar cells due to the low cost starting materials and facile synthesis.
基金financially supported by the Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007)the National Natural Science Foundation of China(No.21875073)+1 种基金the Distinguished Young Scientists Program of Guangdong Province(No.2019B151502021)Guangdong-Hong Kong-Macao joint laboratory of optoelectronic and magnetic functional materials(No.2019B121205002)。
文摘In recent years, non-fullerene acceptors(NFAs) with unfused-ring structure have received extensive attention due to their flexible combination of building blocks and relatively simple synthetic routes. In this work, three new A-D-C-D-A type unfused-ring acceptors(UFAs),named DTBTz EH-IC2F, DTBTz Me-IC2F and DTBTz Me-IC2Cl, were designed and synthesized with dithienobenzotriazole(DTBTz) as the core.Through modification of alkyl chain on the DTBTz unit and change of halogen atoms on the cyanoindanone end groups, the differences in optoelectronic properties of these three small molecule acceptors were investigated. The results show that changes in alkyl chain and halogen atom endow UFAs with different features, including shift in absorption, changes in energy level and molecular packing. When blended with donor PBDB-T, the organic solar cell based on DTBTz Me-IC2Cl achieves the highest device efficiency of 12.3%, while DTBTz EH-IC2F-based device obtains 11.5% efficiency and DTBTz Me-IC2F-based device obtains 12.0% efficiency. The stability tests show that all the devices obtain good efficiency retention rates. These results demonstrate that the introduction of a rigid aromatic ring DTBTz as an intermediate core not only effectively results in highly planar A-D-C-D-A small molecules, but also provides a new reference for the design and development of UFAs in OSCs.
