We report herein an efficient A^1-C=C-A^2-C=C-A^1 type small-molecule 4,4＇-difluoro-4-bora-3a,4a-diaza-sindacene （BODIPY） acceptor （A^1= BODIPY and A^2= diketopyrrolopyrrole （DPP）） by following the A-to-A excit...We report herein an efficient A^1-C=C-A^2-C=C-A^1 type small-molecule 4,4＇-difluoro-4-bora-3a,4a-diaza-sindacene （BODIPY） acceptor （A^1= BODIPY and A^2= diketopyrrolopyrrole （DPP）） by following the A-to-A excited electron delocalization via the BODIPY meso-position, the inherent directionality for the excited electron delocalization. The lowest unoccupied molecular orbital （LUMO） delocalizes across over whole the two flanking A^1 and the central A^2, and the highest occupied molecular orbital （HOMO） localizes dominantly on the -C=C-DPP-C=C- segment. The excited electron upon light excitation of the DPP segment delocalizes over both the BODIPY and DPP segments. The acceptor in chloroform shows an unprecedented plateau-like broad absorption between 550 and 700 nm with a large FWHM value of 195 nm. Upon transition into solid film, the acceptor shows absorption in the whole near ultraviolet-visible-near infrared wavelength region （300-830 nm） with a low band gap of 1.5 eV and a maximum absorptivity of 0.85 × 10^5 cm^-1. Introduction of the ethynyl spacer between the A^1 and A^2 and the close BODIPY-to-DPP LUMO energy levels are crucial for the excited n-electron delocalization across over whole the conjugation backbone. A power conversion efficiency of 6.60% was obtained from the ternary non-fullerene solar cell with PTB7-Th：p-DTS（FBTTh2）2 （0.5 ; 0.5） as the donor materials, which is the highest value among the non-fullerene organic solar cells with BODIPY as the electron acceptor material.展开更多
1 Results In this contribution,the synthesis and characterization of low-band-gap oligothiophenes and copolymers based on fluorene and thiophene units are reported.First,5,5′-dibromo derivative of 1 was synthesised a...1 Results In this contribution,the synthesis and characterization of low-band-gap oligothiophenes and copolymers based on fluorene and thiophene units are reported.First,5,5′-dibromo derivative of 1 was synthesised and used as a building block for synthesis of quinquethiophene and septithiophene analogues of 1 and the synthesis of a novel low band-gap polymer - soluble alternating copolymer 3,which was prepared by the Suzuki coupling of 5,5′-dibromo derivative of 1 with bis(propane-1,3-diyl) 9,9-bis(2-...展开更多
基金Supporting information for this article is available on the WWW under http：//dx.doi.org/10.1002/cjoc.201700542 or from the author. Dedicated to the Special Issue of Polymer Solar Cells.Acknowledgement The authors gratefully acknowledge the financial support ot＂ the National Natural Science Foundation of China （NSFC, Nos. 91433202, 21327805, 91227112 and 21221002）, Chinese Academy of Sciences （CAS, X DB12010200）, and Ministry of Science and Technol- ogy of the People＇s Republic of China （MOST, 2012YQ120060）. The authors gratefully acknowledge Beijing Synchrotron Radiation Facility （BSRF） for supports of GIXRD measurements.
文摘We report herein an efficient A^1-C=C-A^2-C=C-A^1 type small-molecule 4,4＇-difluoro-4-bora-3a,4a-diaza-sindacene （BODIPY） acceptor （A^1= BODIPY and A^2= diketopyrrolopyrrole （DPP）） by following the A-to-A excited electron delocalization via the BODIPY meso-position, the inherent directionality for the excited electron delocalization. The lowest unoccupied molecular orbital （LUMO） delocalizes across over whole the two flanking A^1 and the central A^2, and the highest occupied molecular orbital （HOMO） localizes dominantly on the -C=C-DPP-C=C- segment. The excited electron upon light excitation of the DPP segment delocalizes over both the BODIPY and DPP segments. The acceptor in chloroform shows an unprecedented plateau-like broad absorption between 550 and 700 nm with a large FWHM value of 195 nm. Upon transition into solid film, the acceptor shows absorption in the whole near ultraviolet-visible-near infrared wavelength region （300-830 nm） with a low band gap of 1.5 eV and a maximum absorptivity of 0.85 × 10^5 cm^-1. Introduction of the ethynyl spacer between the A^1 and A^2 and the close BODIPY-to-DPP LUMO energy levels are crucial for the excited n-electron delocalization across over whole the conjugation backbone. A power conversion efficiency of 6.60% was obtained from the ternary non-fullerene solar cell with PTB7-Th：p-DTS（FBTTh2）2 （0.5 ; 0.5） as the donor materials, which is the highest value among the non-fullerene organic solar cells with BODIPY as the electron acceptor material.
文摘1 Results In this contribution,the synthesis and characterization of low-band-gap oligothiophenes and copolymers based on fluorene and thiophene units are reported.First,5,5′-dibromo derivative of 1 was synthesised and used as a building block for synthesis of quinquethiophene and septithiophene analogues of 1 and the synthesis of a novel low band-gap polymer - soluble alternating copolymer 3,which was prepared by the Suzuki coupling of 5,5′-dibromo derivative of 1 with bis(propane-1,3-diyl) 9,9-bis(2-...
