Quinoidal small molecule semiconductors hold huge potential in ambipolar organic field-effect transistors(OFETs)and organic spintronic devices.Here,two quinoidal molecules with methylthio side chains were synthesized ...Quinoidal small molecule semiconductors hold huge potential in ambipolar organic field-effect transistors(OFETs)and organic spintronic devices.Here,two quinoidal molecules with methylthio side chains were synthesized to develop molecular semiconductors with high ambipolar mobility,designated QBDTS and QTBDTS.The theoretical calculation results reveal that QBDTS has a closed-shell structure while QTBDTS showed an open-shell structure with a biradical character(y0)of 0.46 and its magnetic properties were further investigated using electron paramagnetic resonance(EPR)and superconducting quantum interference device(SQUID)methods.The methyl side chains showed a large impact on the molecular orbital levels.The HOMO/LUMO levels of QBDTS and QTBDTS were measured to be-5.66/-4.56 and-5.27/-4.48 eV,respectively,which are favorable for ambipolar charge transport in OFETs.Importantly,the spin-coated QBDTS displayed hole and electron mobilities of 0.01 and 0.5 cm^(2)V^(-1)s^(-1)while QTBDTS showed a record high hole mobility of 1.8 cm^(2)V^(-1)s^(-1)and electron mobility of 0.3 cm^(2)V^(-1)s^(-1).Moreover,comparative studies of the thin film morphologies also manifested the beneficial influence of methyl side chains on film crystallinity and molecule orientation.These results strongly proved that methyl side chain engineering can be a simple but efficient strategy for modulating electronic properties and molecular stacking behaviors.This work also represents a big advancement for quinoidal molecular semiconductors in ambipolar OFET applications.展开更多
The development of polymer solar cells(PSCs)for the donor materials based on benzo[1,2-b:4,5-b′]dithiophene(BDT)has significantly boosted the power conversion efficiency(PCE).However,the PCE of polymer donor material...The development of polymer solar cells(PSCs)for the donor materials based on benzo[1,2-b:4,5-b′]dithiophene(BDT)has significantly boosted the power conversion efficiency(PCE).However,the PCE of polymer donor materials for benzo[1,2-b:4,5-b′]difuran(BDF)-based lags far behind that of their BDT analogs.To further explore efficient copolymers based on BDF units,a two-dimensional(2D)side-chain strategy was proposed to investigate the atom-changing effects on the copolymer donors for the properties of electron and optical.In this study,we designed and synthesized three new BDF-based copolymer donor materials,named PBDF-C,PBDF-O,and PBDF-S.Owing to the balanced charge transport and favorable phase separation of PBDF-S:Y6,a high PCE of 13.4%,a short-circuit current(J sc)of 25.48 mA cm−2,an open-circuit voltage(V oc)of 0.721 V,and a fill factor(FF)of 72.6%was obtained.This research demonstrates that the BDF building block has great potential for constructing conjugated copolymer donors for high-performance PSCs and that 2D side-chain modification is a facile approach for designing high-performance BDF-based copolymer materials.展开更多
Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvem...Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvement,including molecular microstructure,orientating packing and aggregation are urgent for all-small-molecule(ASM)systems.Herein,employing a fluorine-modified two-dimension benzodithiophene(BDT)as central unit,we contrastively synthesized two small-molecule donors,namely BDT-F-SR and BDT-F-R,each welding alkylthio side-chains on thienyl of central BDT unit and the other grafted non-sulfuric alkyl side-chains.As predicted,the synergetic side-chain modification of fluorination and alkyl changeover triggers diverse molecular dipole moments and orientations,resulting in different molecular energy levels,thermal stabilities,molecular planarity and order.Eventually,together with the preeminent small-molecule acceptor Y6,BDT-F-R-based ASM OSCs obtain enhanced power conversion efficiency(PCE)of 13.88%compared to BDT-F-SR-based devices(PCE of 12.75%)with more suitable phase-separation and balanced carrier mobilities.The contrast results reveal that alkyl sidechains seem to be a more satisfactory partner for fluorine-modified 2D BDT-based small-molecule donors compared to alkylthio pendants,and highlight the significance of subtle side-chain modification for molecular structural order fun-tuning and morphology control,laying the foundation for efficient ASM OSCs.展开更多
Multi-stimuli-responsive field-effect transistors(FETs)with organic/polymeric semiconductors have received increasing attention.Herein,we report a novel strategy for fabricating multi-stimuliresponsive polymeric semic...Multi-stimuli-responsive field-effect transistors(FETs)with organic/polymeric semiconductors have received increasing attention.Herein,we report a novel strategy for fabricating multi-stimuliresponsive polymeric semiconductors through the incorporation of spiropyran(SP)groups in the polymer side chains.The semiconducting performances of resultant FETs with a diketopyrrolopyrroles(DPP)-based conjugated donor–acceptor(D–A)polymer,that entails SP units in the side chains(pDSP-1),could be modulated reversibly through UV and visible light irradiations,or UV light irradiation and heating,or acid treatment and heating.Our studies reveal that during the reversible transformations of closed,open,and the protonated forms of spiropyran,achieved by light irradiations,heating,and under acidic conditions,a large dipole moment changes occur,which triggers the reversible variation of semiconducting performance of the FETs.展开更多
为了解决Kumada催化剂转移缩聚(Kumada catalyst transfer polycondensation,KCTP)反应构建的聚噻吩材料结构单一、能级较高等问题,通过KCTP法成功实现了含有4个噻吩单元与硫醚侧链单体的聚合,构建了含有硫代烷基侧链的新型聚噻吩材料(P...为了解决Kumada催化剂转移缩聚(Kumada catalyst transfer polycondensation,KCTP)反应构建的聚噻吩材料结构单一、能级较高等问题,通过KCTP法成功实现了含有4个噻吩单元与硫醚侧链单体的聚合,构建了含有硫代烷基侧链的新型聚噻吩材料(PtTSBO),并通过控制氧化剂间氯过氧苯甲酸(m-CPBA)的用量和反应温度,将侧链上的硫醚选择性地氧化为亚砜或砜基,制备了含有亚砜或砜基的PtTSBO(PtTSOBO或PtTSOOBO)。通过核磁共振氢(1H-NMR)谱、元素分析(EA)、紫外-可见分光(UV-Vis)光谱和电化学(CV)曲线对聚合物的结构、吸光和电学性能进行了表征,并对所制备的光伏器件进行了光电性质研究。结果表明,这种后修饰策略有效地将硫醚官能团转变为强吸电子基团,相比于PtTSBO,聚合物PtTSOBO和PtTSOOBO的能级显著降低,相应光伏器件的开路电压(Voc)得到了提升。展开更多
基金supported by the National Natural Science Foundation of China(21801201,51773160,21975194,22175134)the Research Fund for Distinguished Young Scholars of Hubei Province(2019CFA042)。
文摘Quinoidal small molecule semiconductors hold huge potential in ambipolar organic field-effect transistors(OFETs)and organic spintronic devices.Here,two quinoidal molecules with methylthio side chains were synthesized to develop molecular semiconductors with high ambipolar mobility,designated QBDTS and QTBDTS.The theoretical calculation results reveal that QBDTS has a closed-shell structure while QTBDTS showed an open-shell structure with a biradical character(y0)of 0.46 and its magnetic properties were further investigated using electron paramagnetic resonance(EPR)and superconducting quantum interference device(SQUID)methods.The methyl side chains showed a large impact on the molecular orbital levels.The HOMO/LUMO levels of QBDTS and QTBDTS were measured to be-5.66/-4.56 and-5.27/-4.48 eV,respectively,which are favorable for ambipolar charge transport in OFETs.Importantly,the spin-coated QBDTS displayed hole and electron mobilities of 0.01 and 0.5 cm^(2)V^(-1)s^(-1)while QTBDTS showed a record high hole mobility of 1.8 cm^(2)V^(-1)s^(-1)and electron mobility of 0.3 cm^(2)V^(-1)s^(-1).Moreover,comparative studies of the thin film morphologies also manifested the beneficial influence of methyl side chains on film crystallinity and molecule orientation.These results strongly proved that methyl side chain engineering can be a simple but efficient strategy for modulating electronic properties and molecular stacking behaviors.This work also represents a big advancement for quinoidal molecular semiconductors in ambipolar OFET applications.
基金supported by the National Natural Sci-ence Foundation of China(Grant Nos.51825301 and 52022099)China Postdoctoral Science Foundation(BX20190023)H.Y.W acknowl-edges the financial support of the National Research Foundation of Ko-rea(2019R1A6A1A11044070).
文摘The development of polymer solar cells(PSCs)for the donor materials based on benzo[1,2-b:4,5-b′]dithiophene(BDT)has significantly boosted the power conversion efficiency(PCE).However,the PCE of polymer donor materials for benzo[1,2-b:4,5-b′]difuran(BDF)-based lags far behind that of their BDT analogs.To further explore efficient copolymers based on BDF units,a two-dimensional(2D)side-chain strategy was proposed to investigate the atom-changing effects on the copolymer donors for the properties of electron and optical.In this study,we designed and synthesized three new BDF-based copolymer donor materials,named PBDF-C,PBDF-O,and PBDF-S.Owing to the balanced charge transport and favorable phase separation of PBDF-S:Y6,a high PCE of 13.4%,a short-circuit current(J sc)of 25.48 mA cm−2,an open-circuit voltage(V oc)of 0.721 V,and a fill factor(FF)of 72.6%was obtained.This research demonstrates that the BDF building block has great potential for constructing conjugated copolymer donors for high-performance PSCs and that 2D side-chain modification is a facile approach for designing high-performance BDF-based copolymer materials.
基金the Natural Science Foundation of Chongqing(cstc2019jcyj-msxmX0400)Youth Innovation Promotion Association Chinese Academy of Sciences(2020379)+2 种基金Chongqing Funds for Distinguished Young Scientists(cstc2020jcyj-jqX0018)General Program of National Natural Science Foundation of China(62074149)National Natural Science Foundation of China(51961165102).
文摘Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvement,including molecular microstructure,orientating packing and aggregation are urgent for all-small-molecule(ASM)systems.Herein,employing a fluorine-modified two-dimension benzodithiophene(BDT)as central unit,we contrastively synthesized two small-molecule donors,namely BDT-F-SR and BDT-F-R,each welding alkylthio side-chains on thienyl of central BDT unit and the other grafted non-sulfuric alkyl side-chains.As predicted,the synergetic side-chain modification of fluorination and alkyl changeover triggers diverse molecular dipole moments and orientations,resulting in different molecular energy levels,thermal stabilities,molecular planarity and order.Eventually,together with the preeminent small-molecule acceptor Y6,BDT-F-R-based ASM OSCs obtain enhanced power conversion efficiency(PCE)of 13.88%compared to BDT-F-SR-based devices(PCE of 12.75%)with more suitable phase-separation and balanced carrier mobilities.The contrast results reveal that alkyl sidechains seem to be a more satisfactory partner for fluorine-modified 2D BDT-based small-molecule donors compared to alkylthio pendants,and highlight the significance of subtle side-chain modification for molecular structural order fun-tuning and morphology control,laying the foundation for efficient ASM OSCs.
基金the National Natural Science Foundation of China(NSFC)(nos.21790360,21661132006,and 61890943)the National Key R&D Program of China(2017YFA0204701)+2 种基金the Youth Innovation Promotion Association CAS(no.2015024)for their financial supportWealso thank Dr.Joseph Strzalka and Dr.Zhang Jiang for their assistance with GIWAXS measurementsThe usage of the advanced photon source(APS)at Argonne National Laboratory was supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences under contract no.DE-AC02-06CH11357.
文摘Multi-stimuli-responsive field-effect transistors(FETs)with organic/polymeric semiconductors have received increasing attention.Herein,we report a novel strategy for fabricating multi-stimuliresponsive polymeric semiconductors through the incorporation of spiropyran(SP)groups in the polymer side chains.The semiconducting performances of resultant FETs with a diketopyrrolopyrroles(DPP)-based conjugated donor–acceptor(D–A)polymer,that entails SP units in the side chains(pDSP-1),could be modulated reversibly through UV and visible light irradiations,or UV light irradiation and heating,or acid treatment and heating.Our studies reveal that during the reversible transformations of closed,open,and the protonated forms of spiropyran,achieved by light irradiations,heating,and under acidic conditions,a large dipole moment changes occur,which triggers the reversible variation of semiconducting performance of the FETs.
文摘为了解决Kumada催化剂转移缩聚(Kumada catalyst transfer polycondensation,KCTP)反应构建的聚噻吩材料结构单一、能级较高等问题,通过KCTP法成功实现了含有4个噻吩单元与硫醚侧链单体的聚合,构建了含有硫代烷基侧链的新型聚噻吩材料(PtTSBO),并通过控制氧化剂间氯过氧苯甲酸(m-CPBA)的用量和反应温度,将侧链上的硫醚选择性地氧化为亚砜或砜基,制备了含有亚砜或砜基的PtTSBO(PtTSOBO或PtTSOOBO)。通过核磁共振氢(1H-NMR)谱、元素分析(EA)、紫外-可见分光(UV-Vis)光谱和电化学(CV)曲线对聚合物的结构、吸光和电学性能进行了表征,并对所制备的光伏器件进行了光电性质研究。结果表明,这种后修饰策略有效地将硫醚官能团转变为强吸电子基团,相比于PtTSBO,聚合物PtTSOBO和PtTSOOBO的能级显著降低,相应光伏器件的开路电压(Voc)得到了提升。
