Optimizing the photoactive layer morphology is a simple,promising way to improve the power conversion efficiencies(PCEs)of organic solar cells(OSCs).Here,we compared different post-processing treatments on PM6:Y6 blen...Optimizing the photoactive layer morphology is a simple,promising way to improve the power conversion efficiencies(PCEs)of organic solar cells(OSCs).Here,we compared different post-processing treatments on PM6:Y6 blend films and relevant effects on device performances,including as-cast,thermal annealing and solvent annealing.This solvent annealing processes can effectively improve the vertical distribution and aggregation of polymer donors and small molecule acceptors,then optimize the active layer film morphology,ultimately elevating PCE.Thus,one of champion efficiencies of 18.01%was achieved based on the PM6:Y6 binary OSCs.In addition,a relatively high light utilization efficiency(2.53%)was achieved when a transparent electrode made of Cu(1 nm)and Ag(15 nm)was utilized to fabricate a semitransparent OSC with a remarkable PCE of 13.07%and 19.33%average visible-light transmittance.These results demonstrated that carefully optimizing morphology of active layer is conducive to achieving a high-performance OSC.展开更多
Star-shaped small molecules have attracted great attention for organic solar cells(OSCs)because they have three-dimensional charge-transport characteristics,strong light absorption capacities and easily tunable energy...Star-shaped small molecules have attracted great attention for organic solar cells(OSCs)because they have three-dimensional charge-transport characteristics,strong light absorption capacities and easily tunable energy levels.Herein,three-and four-armed star-shaped small molecule donors,namely BDT-3 Th and BDT-4 Th,respectively,have been successfully designed and synthesized,which used benzodithiophene(BDT)as the central unit.The two star-shaped intermediates(2 a and 2 b)could be simultaneously obtained by one-step of Suzuki coupling,and 1,2-dimethoxyethane played a key role in the Suzuki coupling.Both of them have excellent thermal stability,good solubility and broad absorption.Four-armed BDT-4 Th shows a slightly higher extinction coefficient,a deeper HOMO energy level and an obviously better phase separation morphology when blended with Y6 than three-armed BDT-3 Th.As a result,increased power conversion efficiency(PCE)of 5.83%is obtained in the BDT-4 Th:Y6-based OSC devices,which is obviously higher than that of the BDT-3 Th:Y6-based devices(PCE=3.78%).To the best of our knowledge,this is the highest PCE among the BDT-based star-shaped donors-based OSCs.This result provides an effective strategy to obtain star-shaped small molecule donor materials for high efficient organic solar cells.展开更多
Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the r...Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the rational design of well-matched donor and acceptor materials is extremely essential.In this work,two new small molecular donor materials with subtle change in the conjugated side thiophene rings are synthesized.The subtle change significantly affects the photovoltaic performance of molecular donors.Compared with chlorinated molecule MDJ-Cl,the non-chlorinated analogue MDJ exhibits decreased miscibility with the non-fullerene acceptor Y6,can more efficiently quench the excitons of Y6.As a result,a improved PCE of 11.16% is obtained for MDJ:Y6 based SMOSCs.The results highlight the importance of fine-tuning the molecular structure to achieve high-performance SMOSCs.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars(21925506)the National Natural Science Foundation of China(U21A20331,51773212,81903743,51875384)+2 种基金Ningbo S&T Innovation 2025 Major Special Programme(2018B10055)CAS Key Project of Frontier Science Research(QYZDBSSW-SYS030)Ningbo Natural Science Foundation(2021J192)。
文摘Optimizing the photoactive layer morphology is a simple,promising way to improve the power conversion efficiencies(PCEs)of organic solar cells(OSCs).Here,we compared different post-processing treatments on PM6:Y6 blend films and relevant effects on device performances,including as-cast,thermal annealing and solvent annealing.This solvent annealing processes can effectively improve the vertical distribution and aggregation of polymer donors and small molecule acceptors,then optimize the active layer film morphology,ultimately elevating PCE.Thus,one of champion efficiencies of 18.01%was achieved based on the PM6:Y6 binary OSCs.In addition,a relatively high light utilization efficiency(2.53%)was achieved when a transparent electrode made of Cu(1 nm)and Ag(15 nm)was utilized to fabricate a semitransparent OSC with a remarkable PCE of 13.07%and 19.33%average visible-light transmittance.These results demonstrated that carefully optimizing morphology of active layer is conducive to achieving a high-performance OSC.
基金the financial support for this work by the National Science Fund for Distinguished Young Scholars(No.21925506)National Natural Science Foundation of China(No.51773212)Ningbo S&T Innovation 2025 Major Special Program(No.2018B10055)。
文摘Star-shaped small molecules have attracted great attention for organic solar cells(OSCs)because they have three-dimensional charge-transport characteristics,strong light absorption capacities and easily tunable energy levels.Herein,three-and four-armed star-shaped small molecule donors,namely BDT-3 Th and BDT-4 Th,respectively,have been successfully designed and synthesized,which used benzodithiophene(BDT)as the central unit.The two star-shaped intermediates(2 a and 2 b)could be simultaneously obtained by one-step of Suzuki coupling,and 1,2-dimethoxyethane played a key role in the Suzuki coupling.Both of them have excellent thermal stability,good solubility and broad absorption.Four-armed BDT-4 Th shows a slightly higher extinction coefficient,a deeper HOMO energy level and an obviously better phase separation morphology when blended with Y6 than three-armed BDT-3 Th.As a result,increased power conversion efficiency(PCE)of 5.83%is obtained in the BDT-4 Th:Y6-based OSC devices,which is obviously higher than that of the BDT-3 Th:Y6-based devices(PCE=3.78%).To the best of our knowledge,this is the highest PCE among the BDT-based star-shaped donors-based OSCs.This result provides an effective strategy to obtain star-shaped small molecule donor materials for high efficient organic solar cells.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.51973169,51703172)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015)the Science Foundation of Wuhan Institute of Technology(No.K202025).
文摘Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the rational design of well-matched donor and acceptor materials is extremely essential.In this work,two new small molecular donor materials with subtle change in the conjugated side thiophene rings are synthesized.The subtle change significantly affects the photovoltaic performance of molecular donors.Compared with chlorinated molecule MDJ-Cl,the non-chlorinated analogue MDJ exhibits decreased miscibility with the non-fullerene acceptor Y6,can more efficiently quench the excitons of Y6.As a result,a improved PCE of 11.16% is obtained for MDJ:Y6 based SMOSCs.The results highlight the importance of fine-tuning the molecular structure to achieve high-performance SMOSCs.