In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophys...In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophysical and photovoltaic properties of PFDBCPDT were studied. PFDBCPDT showed a low optical band gap of 1.84 eV, and relatively low HOMO level of-5.69 eV. The best device performance was obtained by PFDBCPDT/PC61BM （1：3） with 0.5 vol% DIO. The device exhibited a power conversion efficiency of 3.06%, with a relatively high open circuit voltage of 0.87 eV.展开更多
The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain olig...The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain oligomeric donor and acceptors for OSC applications.A series of cyclopentadithiophene(CPDT)and benzothiadiazole(BT)-basedπ-conjugated oligomers,i.e.,three oligomeric acceptors(BTDT)n-IC(n=1—3)and one long-chain oligomeric donor(BTDT)4-RD,are facilely synthesized by an atom-and step-economical,and labor-saving direct C—H arylation(DACH)reaction(i.e.,C—H/C—Br cross coupling).Note that(BTDT)4-RD involving five CPDT,four BT and two rhodamine(RD)building blocks is the longest oligomeric donor in the fullerene-free OSC devices ever reported.The dependence of the structure-property-performance correlation of(BTDT)n-IC(n=1—3)and(BTDT)4-RD on theπ-conjugation lengths is thoroughly investigated by opto-electrochemical measurements,bulk heterojunction(BHJ)OSC devices and microscopies.The(BTDT)1-IC:PBDB-T and(BTDT)4-RD:Y6 BHJs achieve power conversion efficiencies of 9.14%and 4.51%,respectively.Our findings demonstrate that DACH reaction is a powerful tool to tune the opto-electronic properties and device performances by regulating the lengths ofπ-conjugated oligomers with varied numbers of repeating units.展开更多
Main observation and conclusion A series of all-donor type alternating(D1-D2)monodisperse oligomers based on cyclopentadithiophene(CPDT)and 1,4-difluoro-benzene(DFB)with gradually increasing chain lengths containing 3...Main observation and conclusion A series of all-donor type alternating(D1-D2)monodisperse oligomers based on cyclopentadithiophene(CPDT)and 1,4-difluoro-benzene(DFB)with gradually increasing chain lengths containing 3 to 15 monomers were successfully synthesized via one-pot C-H direct arylation reaction.As confirmed by various structural characterizations,all these long-chain oligomers are monodispersed with defined structures.The length-dependent optical and electrochemical properties with the evolution from the shortest oligomer(01)to the longest oligomer(07)and their parent polymer P1 have been studied in details.By simply tuning the mixing ratio of discrete oligomers,the photoluminescence(PL)in a wide range of color emissions extending to near-white can be facilely modulated,ilus-trating the potential of these monodisperse conjugated oligomers for light emission application.The atom-,step-and pot-economic synthetic strategy here developed will open the door toward efficient and controllable synthesis ofπ-conjugated oligomers for accu-rate structure-property relationship study and optic&electronic device applications.展开更多
基金financially supported by the 973 Project(Nos.2009CB623601and2009CB930603)the Science Fund for Creative Research Groups(No.20921061)the National Natural Science Foundation of China(Nos.51173179,20904055 and21074130)
文摘In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophysical and photovoltaic properties of PFDBCPDT were studied. PFDBCPDT showed a low optical band gap of 1.84 eV, and relatively low HOMO level of-5.69 eV. The best device performance was obtained by PFDBCPDT/PC61BM （1：3） with 0.5 vol% DIO. The device exhibited a power conversion efficiency of 3.06%, with a relatively high open circuit voltage of 0.87 eV.
基金The National Natural Science Foundation of China(No.22169009)Jiangxi Provincial Natural Science Foundation(No.20212ACB204007)Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(20212BCD42018)are appreciated for financial support。
文摘The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain oligomeric donor and acceptors for OSC applications.A series of cyclopentadithiophene(CPDT)and benzothiadiazole(BT)-basedπ-conjugated oligomers,i.e.,three oligomeric acceptors(BTDT)n-IC(n=1—3)and one long-chain oligomeric donor(BTDT)4-RD,are facilely synthesized by an atom-and step-economical,and labor-saving direct C—H arylation(DACH)reaction(i.e.,C—H/C—Br cross coupling).Note that(BTDT)4-RD involving five CPDT,four BT and two rhodamine(RD)building blocks is the longest oligomeric donor in the fullerene-free OSC devices ever reported.The dependence of the structure-property-performance correlation of(BTDT)n-IC(n=1—3)and(BTDT)4-RD on theπ-conjugation lengths is thoroughly investigated by opto-electrochemical measurements,bulk heterojunction(BHJ)OSC devices and microscopies.The(BTDT)1-IC:PBDB-T and(BTDT)4-RD:Y6 BHJs achieve power conversion efficiencies of 9.14%and 4.51%,respectively.Our findings demonstrate that DACH reaction is a powerful tool to tune the opto-electronic properties and device performances by regulating the lengths ofπ-conjugated oligomers with varied numbers of repeating units.
基金The National Natural Science Foundation of China(No.21374075)is appreciated for financial supports.
文摘Main observation and conclusion A series of all-donor type alternating(D1-D2)monodisperse oligomers based on cyclopentadithiophene(CPDT)and 1,4-difluoro-benzene(DFB)with gradually increasing chain lengths containing 3 to 15 monomers were successfully synthesized via one-pot C-H direct arylation reaction.As confirmed by various structural characterizations,all these long-chain oligomers are monodispersed with defined structures.The length-dependent optical and electrochemical properties with the evolution from the shortest oligomer(01)to the longest oligomer(07)and their parent polymer P1 have been studied in details.By simply tuning the mixing ratio of discrete oligomers,the photoluminescence(PL)in a wide range of color emissions extending to near-white can be facilely modulated,ilus-trating the potential of these monodisperse conjugated oligomers for light emission application.The atom-,step-and pot-economic synthetic strategy here developed will open the door toward efficient and controllable synthesis ofπ-conjugated oligomers for accu-rate structure-property relationship study and optic&electronic device applications.
