The donor–acceptor(D–A)copolymers,which exhibit wide broad absorption and intensified light-harvesting,are highly captivating for applications in solar conversion and optoelectronics.However,designing a polymer stru...The donor–acceptor(D–A)copolymers,which exhibit wide broad absorption and intensified light-harvesting,are highly captivating for applications in solar conversion and optoelectronics.However,designing a polymer structure that can achieve these photophysical properties simultaneously remains a challenge.Herein,we report two novel cyanated units 4-cyanobenzo[1,2-b:6,5-b′:3,4-c″]trithiophene(CBT)and 4,6-dicyanobenzo[1,2-b:6,5-b′:3,4-c″]trithiophene(C2BT)and their corresponding polymers,PCBT and PC2BT.Very interestingly,the PC2BT exhibited a broad absorption band with full width at half maxima(FWHM)of its absorption spectra,almost twice wider than PCBT and benchmark polymers PM6 and D18.Moreover,the PC2BT demonstrated intensified light-harvesting and long-lived exciton.Our in-depth investigation unveiled that the presence of dicyano substitutions induced a strong intramolecular charge transfer(ICT),which,in turn,resulted in the formation of favorable photophysical properties.Therefore,PC2BT-based polymer solar cells(PSCs)exhibited an efficiency of 18.06%,which was a record-setting efficiency for cyanated polymers.This study suggests an efficient strategy for enhancing ICT to design polymers toward favorable photophysical properties and excellent photovoltaic performance.展开更多
We present a new design strategy to synthesize ladder-type thienoacenaphthopyrazine(TAP)-based monomers through two different coupling reactions from starting material 5,6-dibromoacenaphthylene-1,2-dione.By bringing v...We present a new design strategy to synthesize ladder-type thienoacenaphthopyrazine(TAP)-based monomers through two different coupling reactions from starting material 5,6-dibromoacenaphthylene-1,2-dione.By bringing varous electron-deficient groups together(such as five-membered aromatic rings,pyrazine,fluorine,and thiadiazols),this new family of molecules exhibits good stability in ambient conditions and easily tunes the electronic,photophysical and film-forming properties of polymers.The unique molecular shape with its extendedπ-conjugated backbone perpendicular to the polymer chain,offers a remarkable platform for the development of a semiconducting polymer with rare geometry.The planar and enlarged conjugated backbone enables TAP-based copolymers PTAP1 and PTAP2 to exhibit distinguishing solubility properties that are different from small-molecule-based polymers,indicating the advantages of novel ladder-type monomers.Their insolubility in chloroform supports orthogonal solvent processing to fabricate layer-by-layer organic solar cells(LBL-OSCs).Owing to its shorterπ–πstacking distance,higher hole mobility,and more favorable phase separation caused bymultifluorine substitution,polymer PTAP1-based LBL-OSC exhibits the highest efficiency of 17.14%by using Y6-BO as the electron acceptor while the efficiency for the PTAP2-based device is 14.20%.This high efficiency indicates the tremendous potential of these novel building units.展开更多
基金supported by the National Natural Science Foundation of China(grant nos.22179076 and 22225504)the Department of Education of Guangdong Province,China(grant no.2021KCXTD032)+2 种基金the Natural Science Foundation of Guangdong Province,China(grant no.2022A1515011803)the Science and Technology Innovation Fund for College students in Guangdong Province,China(grant no.2020329105600A000003)Guangdong Provincial Key Laboratory of Catalysis,China(grant no.2020B121201002).
文摘The donor–acceptor(D–A)copolymers,which exhibit wide broad absorption and intensified light-harvesting,are highly captivating for applications in solar conversion and optoelectronics.However,designing a polymer structure that can achieve these photophysical properties simultaneously remains a challenge.Herein,we report two novel cyanated units 4-cyanobenzo[1,2-b:6,5-b′:3,4-c″]trithiophene(CBT)and 4,6-dicyanobenzo[1,2-b:6,5-b′:3,4-c″]trithiophene(C2BT)and their corresponding polymers,PCBT and PC2BT.Very interestingly,the PC2BT exhibited a broad absorption band with full width at half maxima(FWHM)of its absorption spectra,almost twice wider than PCBT and benchmark polymers PM6 and D18.Moreover,the PC2BT demonstrated intensified light-harvesting and long-lived exciton.Our in-depth investigation unveiled that the presence of dicyano substitutions induced a strong intramolecular charge transfer(ICT),which,in turn,resulted in the formation of favorable photophysical properties.Therefore,PC2BT-based polymer solar cells(PSCs)exhibited an efficiency of 18.06%,which was a record-setting efficiency for cyanated polymers.This study suggests an efficient strategy for enhancing ICT to design polymers toward favorable photophysical properties and excellent photovoltaic performance.
基金This work was supported by the National Natural Science Foundation of China(grant no.22179076)the Fund for Zhujiang Young Scholar(grant no.18220203)+1 种基金the Natural Science Foundation of Guangdong Province(grant no.2022A1515011803)the Department of Education of Guangdong Province(grant nos.2021KCXTD032 and 2019KCXTD007).
文摘We present a new design strategy to synthesize ladder-type thienoacenaphthopyrazine(TAP)-based monomers through two different coupling reactions from starting material 5,6-dibromoacenaphthylene-1,2-dione.By bringing varous electron-deficient groups together(such as five-membered aromatic rings,pyrazine,fluorine,and thiadiazols),this new family of molecules exhibits good stability in ambient conditions and easily tunes the electronic,photophysical and film-forming properties of polymers.The unique molecular shape with its extendedπ-conjugated backbone perpendicular to the polymer chain,offers a remarkable platform for the development of a semiconducting polymer with rare geometry.The planar and enlarged conjugated backbone enables TAP-based copolymers PTAP1 and PTAP2 to exhibit distinguishing solubility properties that are different from small-molecule-based polymers,indicating the advantages of novel ladder-type monomers.Their insolubility in chloroform supports orthogonal solvent processing to fabricate layer-by-layer organic solar cells(LBL-OSCs).Owing to its shorterπ–πstacking distance,higher hole mobility,and more favorable phase separation caused bymultifluorine substitution,polymer PTAP1-based LBL-OSC exhibits the highest efficiency of 17.14%by using Y6-BO as the electron acceptor while the efficiency for the PTAP2-based device is 14.20%.This high efficiency indicates the tremendous potential of these novel building units.
