有机太阳能电池(organic solar cell,OSC)是由有机材料构成活性层的太阳能电池.苯并[1,2-b:4,5-b']二噻吩(benzo[1,2-b:4,5-b']dithiophene,BDT)由于具有较大的刚性平面共轭结构,可以显著提高π电子的离域能力和分子间的π-π...有机太阳能电池(organic solar cell,OSC)是由有机材料构成活性层的太阳能电池.苯并[1,2-b:4,5-b']二噻吩(benzo[1,2-b:4,5-b']dithiophene,BDT)由于具有较大的刚性平面共轭结构,可以显著提高π电子的离域能力和分子间的π-π相互作用,且易化学修饰,合成方便,成为太阳能电池给体材料研究中的一个"明星分子"单元.目前,已报道的基于BDT共轭单元的有机光伏器件(organic photovoltaic device,OPV)的光电转化效率(power conversion efficiency,PCE)最高已达到9.95%,应用前景巨大.综述了BDT基小分子有机太阳能电池(small molecule organic solar cell,SM-OSC)活性层材料近年来的研究进展,并简要分析了小分子由于主链、侧链、封端基团的差异对器件性能的不同影响.展开更多
热电材料可以将热能直接转化为电能,在回收利用废热发电领域有巨大潜力。相比于无机热电材料,有机热电材料具有机械柔性,适用于智能穿戴设备。利用具有优良平面性的噻吩基异靛青(TIIG)和含有烷氧噻吩侧链的苯并[1,2-b:4,5-b']二噻吩...热电材料可以将热能直接转化为电能,在回收利用废热发电领域有巨大潜力。相比于无机热电材料,有机热电材料具有机械柔性,适用于智能穿戴设备。利用具有优良平面性的噻吩基异靛青(TIIG)和含有烷氧噻吩侧链的苯并[1,2-b:4,5-b']二噻吩(BDT-TO)分别为电子受体和电子给体,设计合成了一种新型给受体(D-A)共轭聚合物。该聚合物有优良的溶解性和热稳定性以及较窄的带隙。聚合物薄膜经过FeCl_(3)/CH_(3)NO_(2)氧化掺杂后,电导率最高可达1.80 S cm^(-1),最优热电性能0.23μW m^(-1) K^(-2)。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
Two new conjugated copolymers, PBDT-T6-TTF and PBDT-T12-TTF, were derived from a novel 4-fluorobenzoyl thienothi- ophene （TTF）. In addition, two types of benzodithiophene （BDT） units with 2,3-dihexylthienyl （T6）...Two new conjugated copolymers, PBDT-T6-TTF and PBDT-T12-TTF, were derived from a novel 4-fluorobenzoyl thienothi- ophene （TTF）. In addition, two types of benzodithiophene （BDT） units with 2,3-dihexylthienyl （T6） and 2,3-didodecylthienyl （T12） substituents, respectively, were successfully synthesized. The effect of the dual two-dimensional （2D） substitutions of the building blocks upon the optoelectronic properties of the polymers was investigated. Generally, the two polymers exhibited good solubility and broad absorption, showing similar optical band gaps of ~1.53 eV. However, PBDT-T6-TTF with its shorter alkyl chain length possessed a larger extinction coefficient in thin solid film. The highest occupied molecular orbital （HOMO） level of PBDT-T6-TTF was located at -5.38 eV while that of PBDT-T12-TTF was at -5.51 eV. In space charge-limited- current （SCLC） measurement, PBDT-T6-TTF and PBDT-T12-TTF displayed respective hole mobilities of 3.0~10-~ and 1.6x10 5 cm2 V-1 s-l. In polymer solar cells, PBDT-T6-TTF and PBDT-T12-TTF showed respective power conversion efficiencies （PCEs） of 2.86% and 1.67%. When 1,8-diiodooctane （DIO） was used as the solvent additive, the PCE of PBDT-T6-TTF was remarkably elevated to 4.85%, but the use of DIO for the PBDT-T12-TTF-blend film resulted in a lower PCE of 0.91%. Atomic force microscopy （AFM） indicated that the superior efficiency of PBDT-T6-TTF with 3% DIO （v/v） should be related to the better continuous phase separation of the blend film. Nevertheless, the morphology of the PBDT-T12-TTF deteriorated when the 3% DIO （v/v） was added. Our results suggest that the alkyl-chain length on the 2D BDT units play an important role in determining the optoelectronic properties of dual 2D BDT-TT-based polymers.展开更多
Two conjugated ethynyl-linked oligomers,oligo(benzodithiophene-ethynylene-benzothiadiazole)(O1)and oligo(benzodithiophene-ethynylene-carbazole)(O2),were synthesized by Sonogashira coupling reaction.Their de-grees of p...Two conjugated ethynyl-linked oligomers,oligo(benzodithiophene-ethynylene-benzothiadiazole)(O1)and oligo(benzodithiophene-ethynylene-carbazole)(O2),were synthesized by Sonogashira coupling reaction.Their de-grees of polymerization were 7 and 10,respectively.Their photophysical and electrochemical properties were in-vestigated.O1 exhibitd two strong absorption bands at 404 nm and 483 nm,and O2 at 401 nm and 429 nm.The re-sults of UV-Vis,cyclic voltammetry(CV)and theoretical calculations showed that O1 has a narrower band gap than O2.The conductivities of O1 and O2 were 1.05×10^(−15) and 6.98×10^(−16) S/cm,respectively,and would increase to 1.23×10^(−10) and 1.05×10^(−10) S/cm after doping with iodine.展开更多
文摘热电材料可以将热能直接转化为电能,在回收利用废热发电领域有巨大潜力。相比于无机热电材料,有机热电材料具有机械柔性,适用于智能穿戴设备。利用具有优良平面性的噻吩基异靛青(TIIG)和含有烷氧噻吩侧链的苯并[1,2-b:4,5-b']二噻吩(BDT-TO)分别为电子受体和电子给体,设计合成了一种新型给受体(D-A)共轭聚合物。该聚合物有优良的溶解性和热稳定性以及较窄的带隙。聚合物薄膜经过FeCl_(3)/CH_(3)NO_(2)氧化掺杂后,电导率最高可达1.80 S cm^(-1),最优热电性能0.23μW m^(-1) K^(-2)。
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financially supported by the National Natural Science Foundation of China(21225418 and 51173048)the National Basic Research Program of China(2013CB834705 and 2014CB643505)GDUPS(2013)
文摘Two new conjugated copolymers, PBDT-T6-TTF and PBDT-T12-TTF, were derived from a novel 4-fluorobenzoyl thienothi- ophene （TTF）. In addition, two types of benzodithiophene （BDT） units with 2,3-dihexylthienyl （T6） and 2,3-didodecylthienyl （T12） substituents, respectively, were successfully synthesized. The effect of the dual two-dimensional （2D） substitutions of the building blocks upon the optoelectronic properties of the polymers was investigated. Generally, the two polymers exhibited good solubility and broad absorption, showing similar optical band gaps of ~1.53 eV. However, PBDT-T6-TTF with its shorter alkyl chain length possessed a larger extinction coefficient in thin solid film. The highest occupied molecular orbital （HOMO） level of PBDT-T6-TTF was located at -5.38 eV while that of PBDT-T12-TTF was at -5.51 eV. In space charge-limited- current （SCLC） measurement, PBDT-T6-TTF and PBDT-T12-TTF displayed respective hole mobilities of 3.0~10-~ and 1.6x10 5 cm2 V-1 s-l. In polymer solar cells, PBDT-T6-TTF and PBDT-T12-TTF showed respective power conversion efficiencies （PCEs） of 2.86% and 1.67%. When 1,8-diiodooctane （DIO） was used as the solvent additive, the PCE of PBDT-T6-TTF was remarkably elevated to 4.85%, but the use of DIO for the PBDT-T12-TTF-blend film resulted in a lower PCE of 0.91%. Atomic force microscopy （AFM） indicated that the superior efficiency of PBDT-T6-TTF with 3% DIO （v/v） should be related to the better continuous phase separation of the blend film. Nevertheless, the morphology of the PBDT-T12-TTF deteriorated when the 3% DIO （v/v） was added. Our results suggest that the alkyl-chain length on the 2D BDT units play an important role in determining the optoelectronic properties of dual 2D BDT-TT-based polymers.
基金The authors are grateful to financial support from the National Natural Science Foundation of China(Nos.20872035,21076078),and the East China University of Science and Technology.
文摘Two conjugated ethynyl-linked oligomers,oligo(benzodithiophene-ethynylene-benzothiadiazole)(O1)and oligo(benzodithiophene-ethynylene-carbazole)(O2),were synthesized by Sonogashira coupling reaction.Their de-grees of polymerization were 7 and 10,respectively.Their photophysical and electrochemical properties were in-vestigated.O1 exhibitd two strong absorption bands at 404 nm and 483 nm,and O2 at 401 nm and 429 nm.The re-sults of UV-Vis,cyclic voltammetry(CV)and theoretical calculations showed that O1 has a narrower band gap than O2.The conductivities of O1 and O2 were 1.05×10^(−15) and 6.98×10^(−16) S/cm,respectively,and would increase to 1.23×10^(−10) and 1.05×10^(−10) S/cm after doping with iodine.
