Isoindigo(IID)is widely used as organic dye and conjugated unit in opto-electronic materials.Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties.Herein,we dev...Isoindigo(IID)is widely used as organic dye and conjugated unit in opto-electronic materials.Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties.Herein,we developed a direct C-H/N-H activation method of IIDs via double alkyne annulations and synthesizedπ-extended IIDs with two pairs of 5/7 membered rings.The structure of theπ-extended IIDs was characterized and confirmed by^(1)H NMR,^(13)C NMR,HRMS and X ray crystal analysis.Their physical properties were characterized by UV-vis absorption,cyclic voltammetry and thermogravimetric analysis.The absorption coefficient of the annulated products enhanced significantly compared with the non-annulated analogue.展开更多
Hexavalent chromium(Cr^(6+))poses significant risks to both individuals and the environment.However,direct detection of Cr^(6+)in fully aqueous media with high sensitivity and selectivity is extremely challenging.Here...Hexavalent chromium(Cr^(6+))poses significant risks to both individuals and the environment.However,direct detection of Cr^(6+)in fully aqueous media with high sensitivity and selectivity is extremely challenging.Herein,an isoindigo-derived chemosensor(II-MT)is developed and utilized as a single use paper-based sensor.This sensor allows for quick and simple screening of Cr^(6+)in water through a significant color change that is visible to the naked eyes.Moreover,via a simple UV detection method,the new sensor enables an accurate trace-level detection of Cr^(6+)at concentration as low as 0.1μM.This detection capability is one order of magnitude lower than the recommended limit for drinking water(0.960μM)set by World Health Organization(WHO).More importantly,the sensor delivers an average recovery of 104.5%and 98.25%for the detection of tap water samples.This convenient,yet accurate,quantification method for Cr^(6+)in spiked tap water was compared to the certified inductive coupled plasma(ICP)method.The agreement between the measurements obtained by our sensor and the ICP method was 93.57%.Mechanistic studies using Fourier Transform Infrared Spectroscopy(FT-IR)indicate a nucleophilic attack to the carbonyl group of II-MT by HCrO_(4)^(-),resulting in the dye color changing from brown to colorless.Overall,this novel chemosensor has a high potential for application as a selective,sensitive,and disposable paper sensor for direct and rapid screening of Cr^(6+)in real world environments.展开更多
Simultaneous photothermal therapy(PTT)and photodynamic therapy(PDT)is beneficial for enhanced cancer therapy due to the synergistic effect.Conventional materials developed for synergistic PTT/PDT are generally multico...Simultaneous photothermal therapy(PTT)and photodynamic therapy(PDT)is beneficial for enhanced cancer therapy due to the synergistic effect.Conventional materials developed for synergistic PTT/PDT are generally multicomponent agents that need complicated preparation procedures and be activated by multiple laser sources.The emerging monocomponent diketopyrrolopyrrole(DPP)-based conjugated small molecular agents enable dual PTT/PDT under a single laser irradiation,but suffer from low singlet oxygen quantum yield,which severely restricts the therapeutic efficacy.Herein,we report acceptor-oriented molecular design of a donor-acceptor-donor(D-A-D)conjugated small molecule(IID-ThTPA)-based phototheranostic agent,with isoindigo(IID)as selective acceptor and triphenylamine(TPA)as donor.The strong D-A strength and narrow singlet-triplet energy gap endow IID-ThTPA nanoparticles(IID-ThTPA NPs)high mass extinction coefficient(18.2 L g^-1 cm^-1),competitive photothermal conversion efficiency(35.4%),and a dramatically enhanced singlet oxygen quantum yield(84.0%)comparing with previously reported monocomponent PTT/PDT agents.Such a high PTT/PDT performance of IID-ThTPA NPs achieved superior tumor cooperative eradicating capability in vitro and in vivo.展开更多
Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated polymer...Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated polymers.The polymers exhibited blue hues in neutralstate with distinct color-to-transmissive reversible electrochromic switching under applied potentials from 0 V to+1.5 V,and showed high coloration efficiencies(436-438 cm^(2)·C^(-1))in near-infrared regions with high switching speeds around 1-2 s under ambient conditions.展开更多
Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo anal...Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo analogue, is designed and synthesized, which has a twisted molecular backbone and R/Sisomers in single crystals. Interestingly, Az II shows the characteristics of both isoindigo and azulene,such as reversible redox behavior and reversible proton responsiveness. UV-vis-NIR,^(1)H NMR and electron paramagnetic resonance(EPR) measurements were carried out to get insights into the possible mechanism of the proton-responsive property of Az II. The results demonstrated that only one azulenyl moiety of molecule of Az II was protonated and deprotonated, and the protonated Az II can be further oxidized to form azulenium cation radicals.展开更多
Isoindigo(IID)has been widely used as strong acceptor unit(A)to construct narrow bandgap polymers in organic field effect transistors(OFETs)and organic solar cells(OSCs).Combing with IID,we chose benzodithiophene(BDT)...Isoindigo(IID)has been widely used as strong acceptor unit(A)to construct narrow bandgap polymers in organic field effect transistors(OFETs)and organic solar cells(OSCs).Combing with IID,we chose benzodithiophene(BDT)as the donor unit(D)and thieno[3,2-b]thiophene(TT)as theπbridge to construct a new type of D-π-A polymer PE70.Based on PE70,we adopt the chlorination strategy to fine-tune photoelectric characteristics and film morphology,and then developed PE74 and PE75.By blending with non-fullerene acceptor(NFA)Y6,device based on PE74 with chloride substitution on the BDT unit showed increasing photovoltaic performance.In addition,further chlorine substitution on the IID(PE75)would greatly reduce the non-radiative voltage loss(ΔV3),and the distorted molecular conformation also took responsible for the excessive recombination.As results,PE74:Y6-based device achieves a power conversion efficiency(PCE)of 11.06%with open-circuit voltage(VOC)of 0.76 V,which are higher than those of PE70:Y6(PCE of 10.40%and VOC of 0.72 V)and PE75:Y6-based device(PCE of 6.24%and VOC of 0.84 V).This work demonstrates the regularity of the photovoltaic performance caused by chlorination strategy in polymer in the non-fullerene OSC devices,which provide important insights into highperformance photovoltaic materials.展开更多
The key factor in photothermal therapy lies in the selection of photothermal agents.Traditional photothermal agents generally have problems such as poor photothermal stability and low photothermal conversion efficienc...The key factor in photothermal therapy lies in the selection of photothermal agents.Traditional photothermal agents generally have problems such as poor photothermal stability and low photothermal conversion efficiency.Herein,we have designed and synthesized an isoindigo(IID)dye.We used isoindigo as the molecular center and introduced common triphenylamine and methoxy groups as rotors.In order to improve the photothermal stability and tumor targeting ability,we encapsulated IID into nanoparticles.As a result,the nanoparticles exhibited high photothermal stability and photothermal conversion efficiency(67%)upon 635 nm laser irradiation.Thus,the nanoparticles demonstrated a significant inhibitory effect on live tumors in photothermal therapy guided by photoacoustic imaging and provided a viable strategy to overcome the treatment challenges.展开更多
Recent advances in organic electronics of novel materials and optoelectronic devices spark great interest in the design and synthesis of high-performance polymer semiconductors. During the last decade, isoindigo(ⅡD) ...Recent advances in organic electronics of novel materials and optoelectronic devices spark great interest in the design and synthesis of high-performance polymer semiconductors. During the last decade, isoindigo(ⅡD) and its derivatives have sprung up as common electron-deficient building blocks and obtained extensive applications in organic field-effect transistors(OFETs).In this review, we first present the current status, basic principles, and general material design strategies for OFETs. Then,multiple ⅡD-type acceptors, mature synthetic routes to monomers, and typical ⅡDs-based conjugated polymers are summarized.We also introduce side-chain engineering and cutting-edge applications, like stretchable transistors, sensing, active-matrix driving, etc., of the classic copolymer poly(isoindigo-co-bithiophene). Green polymerization approaches towards conjugated polymers incorporating ⅡDs are subsequently discussed for efficient polymerization. Finally, we conclude this review and propose in-depth prospects with respect to material synthesis and device applications. Undoubtedly, ⅡDs-based conjugated polymers would occupy a significant position in the future of organic electronics, due to diverse building blocks, mature synthetic pathways, tunable side chains, and unique optoelectronic properties.展开更多
Although isoindigo(IID)-based polymers can realize high charge mobility,these materials are currently confined to fullerenebased organic solar cells(OSCs).Herein,we designed a pair of alternative D-π-A type copolymer...Although isoindigo(IID)-based polymers can realize high charge mobility,these materials are currently confined to fullerenebased organic solar cells(OSCs).Herein,we designed a pair of alternative D-π-A type copolymers,PE71 and PE72,to expand the application in non-fullerene OSCs,where benzo[1,2-b:4,5-b′]thiophene(BDT),thieno[3,2-b]thiophene(TT)and IID units were used as D,A andπ-bridge,respectively.The aim of optimizing the length of alkyl chains on TT bridge is to ensure polymer solubility,crystallinity as well as miscibility with acceptor molecules.We find that PE71 and PE72 exhibit similar optical and electronic properties,but PE71 with shorter hexyl chain tends to aggregate into fiber-like structure.In the end,Y6 is selected as the electron acceptor because of suitable energy levels and complementary absorption spectrum.Finally,PE71:Y6 device realizes a power conversion efficiency(PCE)of 12.03%,which is obviously higher than that of PE72:Y6 device(9.74%)and is also the highest value for IID-based photovoltaic polymers.The charge transport,molecular aggregation,film morphology and energy loss analysis were systematically investigated.The improved photovoltaic performance of PE71:Y6 mainly originates from the better interpenetrating network structure toward facilitating exciton seperation and free charge carrier transportation.Our results indicate that IID-based D-π-A polymers can also be utilized in non-fullerene OSCs and the alkyl chains on the thieno[3,2-b]thiopheneπ-bridge have a vital effect on the photovoltaic performance.展开更多
An isoindigo-based ＂double-cable＂ conjugated polymer bearing perylene bisimide side units was developed via Stille polymerization for application in single-component polymer solar cells, in which a power conversion ...An isoindigo-based ＂double-cable＂ conjugated polymer bearing perylene bisimide side units was developed via Stille polymerization for application in single-component polymer solar cells, in which a power conversion efficiency of 1% with broad photo-response from 300 nm to 800 nm was achieved. There is no evidence of large phase separation confirmed by AFM images and photoluminescence （PL） spectra. The space charge limit current measurements and light intensity dependence measurements indicate that the low electron mobility and the significant recombination of pho- togenerated charge carriers in active layer mainly account for the low performance of our solar cells. Our results suggest that these ＂double-cable＂ are oromising candidates for use in single-component polymer solar cells with NIR photoresponse.展开更多
Most of efficient polymer electron acceptors for polymer solar cells （PSCs） are based on naphthalene diimide or perylene diimide as the electron deficient building block. In this paper, for the first time, we report...Most of efficient polymer electron acceptors for polymer solar cells （PSCs） are based on naphthalene diimide or perylene diimide as the electron deficient building block. In this paper, for the first time, we report polymer electron acceptors based on fluorinated isoindigo IF-lID） as the electron deficient building block. We synthesized two polymer electron acceptors consisting of alternating F-lID unit and thiophene/selenophen unit, They show low-lying LUMo/HOMO energy levels of-3.69/-5.69 eV, high electron mobilities of 1.31 ×10-5 cm2.V-1s-1 and broad absorption spectra with the optical bandgap of 1.61 eV. PSC devices using the two F-liD-based polymers as polymer electron acceptors show encouraging power conversion efficiencies （PCEs） of up to 1.50% with an open-circuit voltage （Voc） of 0.97V, a short-circuit current density （Jsc） of 2.91 mA.cm2, and a fill factor （FF） of 53.2%. This work suggests a new kind of polymer electron acceptors based on F-IID unit.展开更多
Three random conjugated polymers,RP-TiI,RP-2TiI and RP-TVTiI based on both thieno[3,4-c]pyrrole-4,6-dione and isoindigo units have been synthesized by Stille cross-coupling reaction.The optical and electrochemical pro...Three random conjugated polymers,RP-TiI,RP-2TiI and RP-TVTiI based on both thieno[3,4-c]pyrrole-4,6-dione and isoindigo units have been synthesized by Stille cross-coupling reaction.The optical and electrochemical properties of new polymers have been investigated.The resulted polymers showed broad absorption spectra and appropriate energy levels for polymer solar cell applications.The bulk heterojunction devices based on the blend of the polymer RP-TiI and PC_(61)BM showed a power conversion efficiency of 1.75%.展开更多
Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices.However,designing an all-electrically-driven molecular switch is a great challen...Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices.However,designing an all-electrically-driven molecular switch is a great challenge.Here,we experimentally and theoretically investigated the charge transport characteristics of isoindigo(ISO)-molecules at the single-molecule level using the scanning tunneling microscope break junction technique.We find that the single-molecule junctions of ISO-molecules display bias voltage-driven switching characteristics.These switches are realtime,reversible,and nondestructive under low-bias voltages.Experimental results show that the mechanism of the switch is not the transition from nonresonant charge transport to resonant charge transport,but it is the shift of the frontier orbital energy levels of ISO-molecules and the change of the interfacial electronic coupling with bias voltage.Our results will advance the design of high-performance bias voltage-driven molecular switches.展开更多
基金This work is supported by the NSFC(Nos.22071254,21790363,22021002,22090021,22171245)X.-S.Zhang is grateful for the funding from Youth Innovation Promotion Association CAs(No.2021032)+1 种基金This work is also supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.121111KYSB20200022)the CAS-Croucher Funding Scheme for Joint Laboratories.
文摘Isoindigo(IID)is widely used as organic dye and conjugated unit in opto-electronic materials.Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties.Herein,we developed a direct C-H/N-H activation method of IIDs via double alkyne annulations and synthesizedπ-extended IIDs with two pairs of 5/7 membered rings.The structure of theπ-extended IIDs was characterized and confirmed by^(1)H NMR,^(13)C NMR,HRMS and X ray crystal analysis.Their physical properties were characterized by UV-vis absorption,cyclic voltammetry and thermogravimetric analysis.The absorption coefficient of the annulated products enhanced significantly compared with the non-annulated analogue.
基金Saudi Arabian government,particularly Ministry of education,and Umm Al-Qura University for the financial support and the PhD scholarshipthe Australian Research Council(ARC)for the Future Fellowship(Grant No.FT130101337)。
文摘Hexavalent chromium(Cr^(6+))poses significant risks to both individuals and the environment.However,direct detection of Cr^(6+)in fully aqueous media with high sensitivity and selectivity is extremely challenging.Herein,an isoindigo-derived chemosensor(II-MT)is developed and utilized as a single use paper-based sensor.This sensor allows for quick and simple screening of Cr^(6+)in water through a significant color change that is visible to the naked eyes.Moreover,via a simple UV detection method,the new sensor enables an accurate trace-level detection of Cr^(6+)at concentration as low as 0.1μM.This detection capability is one order of magnitude lower than the recommended limit for drinking water(0.960μM)set by World Health Organization(WHO).More importantly,the sensor delivers an average recovery of 104.5%and 98.25%for the detection of tap water samples.This convenient,yet accurate,quantification method for Cr^(6+)in spiked tap water was compared to the certified inductive coupled plasma(ICP)method.The agreement between the measurements obtained by our sensor and the ICP method was 93.57%.Mechanistic studies using Fourier Transform Infrared Spectroscopy(FT-IR)indicate a nucleophilic attack to the carbonyl group of II-MT by HCrO_(4)^(-),resulting in the dye color changing from brown to colorless.Overall,this novel chemosensor has a high potential for application as a selective,sensitive,and disposable paper sensor for direct and rapid screening of Cr^(6+)in real world environments.
基金the financial support provided by the National Key Research and Development Program of China(2016YFA0203600)the Natural Science Foundation of China(NSFC)Project(31822019,51703195,91859116,81430040,81571738)+4 种基金the One Belt and One Road International Cooperation Project from Key Research and Development Program of Zhejiang Province(2019C04024)the National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”,China(2018ZX09711002)the Zhejiang Provincial Natural Science Foundation of China(LGF19C100002)the Fundamental Research Funds for the Central Universities(2019XZZX00415,2020FZZX001-05)the Leading Talent of“Ten Thousand Plan”-National High-Level Talents Special Support Plan。
文摘Simultaneous photothermal therapy(PTT)and photodynamic therapy(PDT)is beneficial for enhanced cancer therapy due to the synergistic effect.Conventional materials developed for synergistic PTT/PDT are generally multicomponent agents that need complicated preparation procedures and be activated by multiple laser sources.The emerging monocomponent diketopyrrolopyrrole(DPP)-based conjugated small molecular agents enable dual PTT/PDT under a single laser irradiation,but suffer from low singlet oxygen quantum yield,which severely restricts the therapeutic efficacy.Herein,we report acceptor-oriented molecular design of a donor-acceptor-donor(D-A-D)conjugated small molecule(IID-ThTPA)-based phototheranostic agent,with isoindigo(IID)as selective acceptor and triphenylamine(TPA)as donor.The strong D-A strength and narrow singlet-triplet energy gap endow IID-ThTPA nanoparticles(IID-ThTPA NPs)high mass extinction coefficient(18.2 L g^-1 cm^-1),competitive photothermal conversion efficiency(35.4%),and a dramatically enhanced singlet oxygen quantum yield(84.0%)comparing with previously reported monocomponent PTT/PDT agents.Such a high PTT/PDT performance of IID-ThTPA NPs achieved superior tumor cooperative eradicating capability in vitro and in vivo.
基金financially supported by the National Natural Science Foundation of China(Nos.21674060 and 51603123)。
文摘Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated polymers.The polymers exhibited blue hues in neutralstate with distinct color-to-transmissive reversible electrochromic switching under applied potentials from 0 V to+1.5 V,and showed high coloration efficiencies(436-438 cm^(2)·C^(-1))in near-infrared regions with high switching speeds around 1-2 s under ambient conditions.
基金financially supported by the National Natural Science Foundation of China (Nos. 21790362, 22075310 and21522209)the “Strategic Priority Research Program of Chinese Academy of Sciences”(No. XDB12010100)+1 种基金the Science and Technology Commission of Shanghai Municipality (Nos. 19XD1424700 and18JC1410600)SIOC. An early preprint of this work appeared on Chem Rxiv [47]。
文摘Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo analogue, is designed and synthesized, which has a twisted molecular backbone and R/Sisomers in single crystals. Interestingly, Az II shows the characteristics of both isoindigo and azulene,such as reversible redox behavior and reversible proton responsiveness. UV-vis-NIR,^(1)H NMR and electron paramagnetic resonance(EPR) measurements were carried out to get insights into the possible mechanism of the proton-responsive property of Az II. The results demonstrated that only one azulenyl moiety of molecule of Az II was protonated and deprotonated, and the protonated Az II can be further oxidized to form azulenium cation radicals.
基金the National Key Research and Development Program of China(2017YFA0206600)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH033)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB36000000)the National Natural Science Foundation of China(NSFC,Nos.21875052,51873044,52073067).
文摘Isoindigo(IID)has been widely used as strong acceptor unit(A)to construct narrow bandgap polymers in organic field effect transistors(OFETs)and organic solar cells(OSCs).Combing with IID,we chose benzodithiophene(BDT)as the donor unit(D)and thieno[3,2-b]thiophene(TT)as theπbridge to construct a new type of D-π-A polymer PE70.Based on PE70,we adopt the chlorination strategy to fine-tune photoelectric characteristics and film morphology,and then developed PE74 and PE75.By blending with non-fullerene acceptor(NFA)Y6,device based on PE74 with chloride substitution on the BDT unit showed increasing photovoltaic performance.In addition,further chlorine substitution on the IID(PE75)would greatly reduce the non-radiative voltage loss(ΔV3),and the distorted molecular conformation also took responsible for the excessive recombination.As results,PE74:Y6-based device achieves a power conversion efficiency(PCE)of 11.06%with open-circuit voltage(VOC)of 0.76 V,which are higher than those of PE70:Y6(PCE of 10.40%and VOC of 0.72 V)and PE75:Y6-based device(PCE of 6.24%and VOC of 0.84 V).This work demonstrates the regularity of the photovoltaic performance caused by chlorination strategy in polymer in the non-fullerene OSC devices,which provide important insights into highperformance photovoltaic materials.
基金financially supported by the National Natural Science Foundation of China(22078046)Fundamental Research Fundamental Funds for the Central Universities(DUT22LAB601)+1 种基金Liaoning Binhai Laboratory(LBLB-2023-03)China Postdoctoral Science Foundation(2023M740487)。
文摘The key factor in photothermal therapy lies in the selection of photothermal agents.Traditional photothermal agents generally have problems such as poor photothermal stability and low photothermal conversion efficiency.Herein,we have designed and synthesized an isoindigo(IID)dye.We used isoindigo as the molecular center and introduced common triphenylamine and methoxy groups as rotors.In order to improve the photothermal stability and tumor targeting ability,we encapsulated IID into nanoparticles.As a result,the nanoparticles exhibited high photothermal stability and photothermal conversion efficiency(67%)upon 635 nm laser irradiation.Thus,the nanoparticles demonstrated a significant inhibitory effect on live tumors in photothermal therapy guided by photoacoustic imaging and provided a viable strategy to overcome the treatment challenges.
基金supported by the National Natural Science Foundation of China (61890940)the National Key R&D Programof “Key Scientific Issues of Transformative Technology” (2018YFA0703200)the CAS-Croucher Funding Scheme for Joint Laboratories and the Chinese Academy of Sciences Research Program (121111KYSB20200036)。
文摘Recent advances in organic electronics of novel materials and optoelectronic devices spark great interest in the design and synthesis of high-performance polymer semiconductors. During the last decade, isoindigo(ⅡD) and its derivatives have sprung up as common electron-deficient building blocks and obtained extensive applications in organic field-effect transistors(OFETs).In this review, we first present the current status, basic principles, and general material design strategies for OFETs. Then,multiple ⅡD-type acceptors, mature synthetic routes to monomers, and typical ⅡDs-based conjugated polymers are summarized.We also introduce side-chain engineering and cutting-edge applications, like stretchable transistors, sensing, active-matrix driving, etc., of the classic copolymer poly(isoindigo-co-bithiophene). Green polymerization approaches towards conjugated polymers incorporating ⅡDs are subsequently discussed for efficient polymerization. Finally, we conclude this review and propose in-depth prospects with respect to material synthesis and device applications. Undoubtedly, ⅡDs-based conjugated polymers would occupy a significant position in the future of organic electronics, due to diverse building blocks, mature synthetic pathways, tunable side chains, and unique optoelectronic properties.
基金the National Key Research and Development Program of China(2017YFA0206600)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDB-SSW-SLH033)+1 种基金the National Natural Science Foundation of China(NSFC,51673048,21875052)the Natural Science Foundation of Shanghai(19ZR1401400)。
文摘Although isoindigo(IID)-based polymers can realize high charge mobility,these materials are currently confined to fullerenebased organic solar cells(OSCs).Herein,we designed a pair of alternative D-π-A type copolymers,PE71 and PE72,to expand the application in non-fullerene OSCs,where benzo[1,2-b:4,5-b′]thiophene(BDT),thieno[3,2-b]thiophene(TT)and IID units were used as D,A andπ-bridge,respectively.The aim of optimizing the length of alkyl chains on TT bridge is to ensure polymer solubility,crystallinity as well as miscibility with acceptor molecules.We find that PE71 and PE72 exhibit similar optical and electronic properties,but PE71 with shorter hexyl chain tends to aggregate into fiber-like structure.In the end,Y6 is selected as the electron acceptor because of suitable energy levels and complementary absorption spectrum.Finally,PE71:Y6 device realizes a power conversion efficiency(PCE)of 12.03%,which is obviously higher than that of PE72:Y6 device(9.74%)and is also the highest value for IID-based photovoltaic polymers.The charge transport,molecular aggregation,film morphology and energy loss analysis were systematically investigated.The improved photovoltaic performance of PE71:Y6 mainly originates from the better interpenetrating network structure toward facilitating exciton seperation and free charge carrier transportation.Our results indicate that IID-based D-π-A polymers can also be utilized in non-fullerene OSCs and the alkyl chains on the thieno[3,2-b]thiopheneπ-bridge have a vital effect on the photovoltaic performance.
文摘An isoindigo-based ＂double-cable＂ conjugated polymer bearing perylene bisimide side units was developed via Stille polymerization for application in single-component polymer solar cells, in which a power conversion efficiency of 1% with broad photo-response from 300 nm to 800 nm was achieved. There is no evidence of large phase separation confirmed by AFM images and photoluminescence （PL） spectra. The space charge limit current measurements and light intensity dependence measurements indicate that the low electron mobility and the significant recombination of pho- togenerated charge carriers in active layer mainly account for the low performance of our solar cells. Our results suggest that these ＂double-cable＂ are oromising candidates for use in single-component polymer solar cells with NIR photoresponse.
文摘Most of efficient polymer electron acceptors for polymer solar cells （PSCs） are based on naphthalene diimide or perylene diimide as the electron deficient building block. In this paper, for the first time, we report polymer electron acceptors based on fluorinated isoindigo IF-lID） as the electron deficient building block. We synthesized two polymer electron acceptors consisting of alternating F-lID unit and thiophene/selenophen unit, They show low-lying LUMo/HOMO energy levels of-3.69/-5.69 eV, high electron mobilities of 1.31 ×10-5 cm2.V-1s-1 and broad absorption spectra with the optical bandgap of 1.61 eV. PSC devices using the two F-liD-based polymers as polymer electron acceptors show encouraging power conversion efficiencies （PCEs） of up to 1.50% with an open-circuit voltage （Voc） of 0.97V, a short-circuit current density （Jsc） of 2.91 mA.cm2, and a fill factor （FF） of 53.2%. This work suggests a new kind of polymer electron acceptors based on F-IID unit.
基金This work was supported by the National Natural Science Foundation of China(NSFC grant Nos.21174084,21274087)the Doctoral Fund of the Ministry of Education of China(grant No.20120073110032).
文摘Three random conjugated polymers,RP-TiI,RP-2TiI and RP-TVTiI based on both thieno[3,4-c]pyrrole-4,6-dione and isoindigo units have been synthesized by Stille cross-coupling reaction.The optical and electrochemical properties of new polymers have been investigated.The resulted polymers showed broad absorption spectra and appropriate energy levels for polymer solar cell applications.The bulk heterojunction devices based on the blend of the polymer RP-TiI and PC_(61)BM showed a power conversion efficiency of 1.75%.
基金supported by the National Natural Science Foundation of China(grant nos.21875279,22075080,and 52273176)the Shanghai Municipal Science and Technology Major Project(grant no.2018SHZDZX03)the Fundamental Research Funds for the Central Universities,and East China University of Science and Technology.
文摘Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices.However,designing an all-electrically-driven molecular switch is a great challenge.Here,we experimentally and theoretically investigated the charge transport characteristics of isoindigo(ISO)-molecules at the single-molecule level using the scanning tunneling microscope break junction technique.We find that the single-molecule junctions of ISO-molecules display bias voltage-driven switching characteristics.These switches are realtime,reversible,and nondestructive under low-bias voltages.Experimental results show that the mechanism of the switch is not the transition from nonresonant charge transport to resonant charge transport,but it is the shift of the frontier orbital energy levels of ISO-molecules and the change of the interfacial electronic coupling with bias voltage.Our results will advance the design of high-performance bias voltage-driven molecular switches.
