To construct efficient low band gap polymers,increasing the Quinone structure of the polymer backbone could be one desirable strategy.In this work,two D–Q–A–Q polymers P1 and P2 were designed and synthesized with t...To construct efficient low band gap polymers,increasing the Quinone structure of the polymer backbone could be one desirable strategy.In this work,two D–Q–A–Q polymers P1 and P2 were designed and synthesized with thiophenopyrrole diketone(TPD)and benzothiadiazole(BT)unit as the core and ester linked thieno[3,4-b]thiophene(TT)segment as π-bridging,and the main focus is to make a comparative analysis of different cores in the influence of the optical,electrochemical,photochemical and morphological properties.Compared with the reported PBDTTEH–TBTTHD-i,P1 exhibited the decreased HOMO energy level of-5.38 e V and lower bandgap of 1.48 e V.Furthermore,when replaced with BT core,P2 showed a red-shifted absorption profile of polymer but with up-shifted HOMO energy level.When fabricated the photovoltaic devices in conventional structure,just as expected,the introduction of ester substituent made an obvious increase of VOC from 0.63 to 0.74 V for P1.Besides,due to the deep HOMO energy level,higher hole mobility and excellent phase separation with PC71 BM,a superior photovoltaic performance(PCE=7.13%)was obtained with a short-circuit current density(JSC)of 14.9 m A/cm^2,significantly higher than that of P2(PCE=2.23%).Generally,this study highlights that the strategy of inserting quinoid moieties into D–A polymers could be optional in LBG-polymers design and presents the importance and comparison of potentially competent core groups.展开更多
Despite the rapid advances of red and green perovskite light-emitting diodes(Pe LEDs),achieving high brightness with high external quantum efficiency(EQE)remains a challenge for the pure-blue Pe LEDs,which greatly hin...Despite the rapid advances of red and green perovskite light-emitting diodes(Pe LEDs),achieving high brightness with high external quantum efficiency(EQE)remains a challenge for the pure-blue Pe LEDs,which greatly hinders their practical applications,such as white-light illumination and in optical communication as a high-speed and low-loss light source.Herein,we report a high-performance pure-blue Pe LED based on mixed-halide quasi-2D perovskites incorporated with a zwitterionic molecule of 3-(benzyldimethylammonio)propanesulfonate(3-BAS).Experimental and density functional theory analysis reveals that 3-BAS can simultaneously eliminate non-radiative recombination loss,suppress halide migration,and regulate phase distribution for smoothing energy transfer in the mixed-halide quasi-2D perovskites,leading to the final perovskites with high photoluminescence quantum yield and robust spectrum stability.Thus,the highperformance pure-blue Pe LED with a recorded brightness with 1806 cd m-2and a relative higher EQE of 9.25%is achieved,which is successfully demonstrated in a visible light communication system for voice signal transmission.We pave the way for achieving highly efficient pure-blue Pe LEDs with great application potential in future optical communication networks.展开更多
Side-chain symmetry-breaking strategy plays an important role in developing photovoltaic materials for high-efficiency all-small-molecule organic solar cells(ASM OSCs).However,the power conversion efficiencies(PCEs)of...Side-chain symmetry-breaking strategy plays an important role in developing photovoltaic materials for high-efficiency all-small-molecule organic solar cells(ASM OSCs).However,the power conversion efficiencies(PCEs)of ASM OSCs still lag behind their polymer-based counterparts,which can be attributed to the difficulties in achieving favorable morphology.Herein,two asymmetric porphyrin-based donors named DAPor-DPP and DDPor-DPP were synthesized,presenting stronger intermolecular interaction and closer molecular stacking compared to the symmetric ZnP-TEH.The DAPor-DPP:6TIC blend afforded a favorablemorphologywith nanoscale phase separation and more ordered molecular packing,thus achievingmore efficient charge transportation and suppressed charge recombination.Consequently,the DAPor-DPP:6TIC-based device exhibited superior photovoltaic parameters,yielding a champion PCE of 16.62%higher than that of the DDPor-DPP-based device(14.96%).To our knowledge,16.62%can be ranked as one of the highest PCE values among the binary ASM OSC filed.Thiswork provides a prospective approach to address the challenge ofASM OSCs in improving film morphology and further achieving high efficiency via side-chain symmetry-breaking strategy,exhibiting great potential in constructing efficient ASM OSCs.展开更多
Exciton binding energy(E_(b))has been regarded as a critical parameter in charge separation during photovoltaic conversion.Minimizing the E_(b) of the photovoltaic materials can facilitate the exciton dissociation in ...Exciton binding energy(E_(b))has been regarded as a critical parameter in charge separation during photovoltaic conversion.Minimizing the E_(b) of the photovoltaic materials can facilitate the exciton dissociation in low-driving force organic solar cells(OSCs)and thus improve the power conversion efficiency(PCE);nevertheless,diminishing the E_(b) with deliberate design principles remains a significant challenge.Herein,bulky side chain as steric hindrance structure was inserted into Y-series acceptors to minimize the E_(b) by modulating the intra-and intermolecular interaction.Theoretical and experimental results indicate that steric hindrance-induced optimal intra-and intermolecular interaction can enhance molecular polarizability,promote electronic orbital overlap between molecules,and facilitate delocalized charge trans-fer pathways,thereby resulting in a low E_(b).The conspicuously reduced E_(b) obtained in Y-ChC5 with pinpoint steric hindrance modulation can minimize the detrimental effects on exciton dissociation in low-driving-force OSCs,achieving a remarkable PCE of 19.1%with over 95%internal quantum efficiency.Our study provides a new molecular design rationale to reduce the E_(b).展开更多
To clearly show how important the impact of side chains on organic solar cells(OSCs)is,we designed three acceptors IDIC-CxPh(x=4,5,or 6)via subtle side-chain regulation.Despite this small change,significant distinctio...To clearly show how important the impact of side chains on organic solar cells(OSCs)is,we designed three acceptors IDIC-CxPh(x=4,5,or 6)via subtle side-chain regulation.Despite this small change,significant distinctions were detected.IDIC-C4Ph devices achieve an optimal efficiency of 13.94%under thermal annealing,but thermal-assistant solvent-vapor annealing hugely suppresses the efficiencies to 10%.However,the C6Ph side chain endows extremely disordered stacking orientations,generating moderate efficiencies of~12.50%.Excitingly,the IDIC-C5Ph affords an unexpected two-channel p-p charge transport(TCCT)property,boosting the fill factor(FF)by up to 80.02%and efficiency to 14.56%,ranking the best among five-ring fused-ladder-type acceptors.Impressively,the special TCCT behavior of IDIC-C5Ph enables 470 nm thick-film OSC with a high FF of up to 70.12%and efficiency of 13.01%,demonstrating the great promise in fabricating largescale OSCs.展开更多
A new star-shaped small molecule named TCNR3TTPA,with a triphenylamine(TPA)unit as the central building block and2-(1,1-dicyanomethylene)-3-octyl rhodanine(CNR)as the end-capped group,has been designed and synthesized...A new star-shaped small molecule named TCNR3TTPA,with a triphenylamine(TPA)unit as the central building block and2-(1,1-dicyanomethylene)-3-octyl rhodanine(CNR)as the end-capped group,has been designed and synthesized.TCNR3TTPA showed a deep highest occupied molecular orbital(HOMO)energy level( 5.60 e V)and broad absorption.The solution-processed bulk heterojunction(BHJ)solar cells based on TCNR3TTPA:PC61BM(1:1,w/w)exhibited a high open-circuit voltage(Voc)of 0.99 V,a short-circuit current density(Jsc)of 5.76 m A/cm2,and a power conversion efficiency(PCE)of 2.50%under the illumination of AM 1.5 G,100 m W/cm2.The high Voc is ascribed to the strong electron-with-drawing ability of the end-capped 2-(1,1-dicyanomethylene)-3-octyl rhodanine group.These results demonstrated that the Voc of small-molecule organic solar cells could be increased by introducing a strong electron-withdrawing end-capped block,and that this is an effective strategy to design high-performance small molecules for organic solar cells.展开更多
Single perylene diimide(PDI)used as a non-fullerene acceptor(NFA)in organic solar cells(OSCs)is enticing because of its low cost and excellent stability.To improve the photovoltaic performance,it is vital to narrow th...Single perylene diimide(PDI)used as a non-fullerene acceptor(NFA)in organic solar cells(OSCs)is enticing because of its low cost and excellent stability.To improve the photovoltaic performance,it is vital to narrow the bandgap and regulate the stacking behavior.To address this challenge,we synthesize soluble perylenetetracarboxylic bisbenzimidazole(PTCBI)molecules with a bulky side chain at the bay region,by replacing the widely used“swallow tail”type alkyl chains at the imide position of PDI molecules with a planar benzimidazole structure.Compared with PDI molecules,PTCBI molecules exhibit red-shifted UV–vis absorption spectra with larger extinction coefcient,and one magnitude higher electron mobility.Finally,OSCs based on one soluble PTCBI-type NFA,namely MAS-7,exhibit a champion power conversion efciency(PCE)of 4.34%,which is signifcantly higher than that of the corresponding PDI-based OSCs and is the highest PCE of PTCBI-based OSCs reported.These results highlight the potential of soluble PTCBI derivatives as NFAs in OSCs.展开更多
The mechanical properties of bulk-heterojunction(BHJ)films play critical roles in the operational stability of flexible polymer solar cells(PSCs).In this study,the multi-scale mechanical properties of the BHJ films co...The mechanical properties of bulk-heterojunction(BHJ)films play critical roles in the operational stability of flexible polymer solar cells(PSCs).In this study,the multi-scale mechanical properties of the BHJ films containing three representative electron acceptors are systematically evaluated.Interestingly,the tensile moduli of the films based on PC_(71)BM,Y6,and PRi-C39 decrease sequentially,and their fracture strain and toughness show an increasing trend.Moreover,the nanoindentation moduli of the films based on these acceptors vary in accordance with the results of tensile characterizations.Creep analyses illustrate that the occurrence of creep deformation in the PC_(71)BM,Y6,and PRi-C39-based films decrease sequentially.Contact angle tests demonstrate that the donor-acceptor interactions greatly affect the mechanical properties of these films.All results above demonstrate the effects of acceptor type on the multi-scale mechanical properties of the BHJ films,which are important for the development of reliable flexible PSCs.展开更多
Objective::Data comparing the outcomes of MiStent(Micell Technologies,Durham,North Carolina,USA)microcrystalline biodegradable polymer(BP)drug-eluting stent(DES)and those of another post-marketing BP-DES,TIVOLI(EssenT...Objective::Data comparing the outcomes of MiStent(Micell Technologies,Durham,North Carolina,USA)microcrystalline biodegradable polymer(BP)drug-eluting stent(DES)and those of another post-marketing BP-DES,TIVOLI(EssenTech,Beijing,China)are rare.This study sought to compare the angiographic efficacy and clinical outcomes of the microcrystalline BP sirolimus-eluting stent(SES)system MiStent and those of TIVOLI BP-SES.Methods::The DESSOLVE-C trial was a prospective,single-blinded,multicenter,randomized trial(NCT02448524),which randomly assigned patients with de novo coronary lesions to receive MiStent or TIVOLI BP-SES by a 1:1 ratio.The primary endpoint was a non-inferiority comparison of in-stent late lumen loss(LLL)by quantitative coronary angiography at 9 months.The secondary endpoint was device-related clinical cardiovascular composite events(target lesion failure(TLF),composite of cardiac death,target vessel myocardial infarction(MI),and clinically driven target lesion revascularization)and 1-year outcomes.Results::A total of 428 patients(216 patients in the MiStent group and 212 patients in the TIVOLI group)were enrolled and included in an intention-to-treat analysis.MiStent was not only non-inferior but superior to TIVOLI for in-stent LLL at 9 months((0.23±0.37)mm vs.(0.34±0.48)mm,P for non-inferiority<0.001,P for superiority=0.02).Although without significant difference,the rate of TLF in MiStent was quantitatively lower than that in TIVOLI(3.70%vs.6.60%;P=0.17).Conclusion::Compared with TIVOLI BP-SES,the MiStent system was superior in in-stent LLL at 9 months and had a comparable clinical benefit at 1 year in de novo coronary lesions.展开更多
Constructing the low-cost,high-efficiency,and good batch-to-batch reproducibility polymer donor is vitally important for the application of organic solar cells.Herein,we develop a structurally simple carboxylate-subst...Constructing the low-cost,high-efficiency,and good batch-to-batch reproducibility polymer donor is vitally important for the application of organic solar cells.Herein,we develop a structurally simple carboxylate-substituted thiazole as an electronwithdrawing building block to construct a low-cost polymer,PBTTzE,containing a facilely prepared chlorinated benzo[1,2-b:4,5-b′]dithiophene(BDTCl)donor unit.Benefiting from synergistic electron deficient effects of chlorination and ester group and C=N,as well as the noncovalent interaction of S…O and S…N,PBTTzE exhibits a deep HOMO energy level(−5.59 eV),and a planar skeleton structure.When combined with the IT-4F acceptor,the polymer(54 kDa)demonstrated a champion PCE of 15.87%,which is the highest value in the IT-4F-based binary devices to date.Moreover,PBTTzE exhibits excellent batch-tobatch reproducibility due to its very similar PCEs within a range of 43–76 kDa.In addition,an alloyed state and complementary absorption can be formed between PM6 and PBTTzE.Therefore,in a ternary device with PBTTzE added to the PM6:BTP-eC9 blend,a top PCE of 18.76%is achieved due to the suppressed energy loss,prolonged exciton diffusion distance,and improved charge transport.Our work demonstrates that the carboxylate-substituted thiazole is a highly promising acceptor unit for constructing low-cost and high-performance polymers.展开更多
Currently,friction characteristics obtained from empirical parameters or soil direct shear tests are widely applied in the resistance calculation and operational parameter optimization of soil tillage components.Howev...Currently,friction characteristics obtained from empirical parameters or soil direct shear tests are widely applied in the resistance calculation and operational parameter optimization of soil tillage components.However,the operation of soiltouching components is a dynamic process,and there are few reports on the dynamic friction characteristics of soil-contacting components in agricultural tillage based on factors such as different moisture content,pressure,and relative velocity.Herein,a test device to measure the friction characteristics of compressible bulk materials was developed:the interface friction between the soil and 65Mn plate and the internal friction characteristics of soil were tested using this device,and the dynamic changes of interface friction coefficient and internal friction coefficient with moisture content,pressure,and relative velocity were obtained.Based on the dynamic friction parameters of soil,the ditching resistance model of a typical ploughshare opener was established,the ditching resistance value was predicted,and field experiments were performed under different operating speeds(0.5 m/s,0.7 m/s,and 0.9 m/s)and ditching depths(60 mm,100 mm,and 140 mm).The results indicated that the calculated values of the ditching resistance model based on the dynamic friction parameters of soil reduced the error by 15%compared with the calculated values based on the friction characteristics of the soil direct shear test,which verified the accuracy of the ditching resistance model and the validity of the parameters obtained from the test device for the friction characteristics of compressible bulk materials.In addition,the minimum ditching resistance can be obtained when the ditching speed is 0.7 m/s at the same ditching depths,which is consistent with the dynamic friction characteristics of soil.It can be found that the dynamic friction characteristics of bulk materials have basic theoretical support for the optimization of operational component structures and operational parameters.展开更多
基金the National Natural Science Foundation of China (21604092, 51573205 and 51773220)China Postdoctoral Science Foundation (2017M610453+1 种基金the Youth Innovation Promotion Association CAS (2016194) for financial supportthe CAS-TWAS President’s Fellowship Program for Ph.D
文摘To construct efficient low band gap polymers,increasing the Quinone structure of the polymer backbone could be one desirable strategy.In this work,two D–Q–A–Q polymers P1 and P2 were designed and synthesized with thiophenopyrrole diketone(TPD)and benzothiadiazole(BT)unit as the core and ester linked thieno[3,4-b]thiophene(TT)segment as π-bridging,and the main focus is to make a comparative analysis of different cores in the influence of the optical,electrochemical,photochemical and morphological properties.Compared with the reported PBDTTEH–TBTTHD-i,P1 exhibited the decreased HOMO energy level of-5.38 e V and lower bandgap of 1.48 e V.Furthermore,when replaced with BT core,P2 showed a red-shifted absorption profile of polymer but with up-shifted HOMO energy level.When fabricated the photovoltaic devices in conventional structure,just as expected,the introduction of ester substituent made an obvious increase of VOC from 0.63 to 0.74 V for P1.Besides,due to the deep HOMO energy level,higher hole mobility and excellent phase separation with PC71 BM,a superior photovoltaic performance(PCE=7.13%)was obtained with a short-circuit current density(JSC)of 14.9 m A/cm^2,significantly higher than that of P2(PCE=2.23%).Generally,this study highlights that the strategy of inserting quinoid moieties into D–A polymers could be optional in LBG-polymers design and presents the importance and comparison of potentially competent core groups.
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 41172110 and 61107090） and Shandong Provincial Natural Science Foundation （Grant No. ZR2011BZ007）.
基金the support of the National Natural Science Foundation of China(NSFC)(61774077,12304473,62175094)the Key Projects of Joint Fund of Basic and Applied Basic Research Fund of Guangdong Province(2019B1515120073,2019B090921002)+3 种基金the Guangdong Science and Technology Research Foundation(2020A1414010036)the High-End Foreign Experts Project(G20200019046)the Young Talent Support Project of Henan Province(2024HYTP001)the Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(JDGD-202302)
文摘Despite the rapid advances of red and green perovskite light-emitting diodes(Pe LEDs),achieving high brightness with high external quantum efficiency(EQE)remains a challenge for the pure-blue Pe LEDs,which greatly hinders their practical applications,such as white-light illumination and in optical communication as a high-speed and low-loss light source.Herein,we report a high-performance pure-blue Pe LED based on mixed-halide quasi-2D perovskites incorporated with a zwitterionic molecule of 3-(benzyldimethylammonio)propanesulfonate(3-BAS).Experimental and density functional theory analysis reveals that 3-BAS can simultaneously eliminate non-radiative recombination loss,suppress halide migration,and regulate phase distribution for smoothing energy transfer in the mixed-halide quasi-2D perovskites,leading to the final perovskites with high photoluminescence quantum yield and robust spectrum stability.Thus,the highperformance pure-blue Pe LED with a recorded brightness with 1806 cd m-2and a relative higher EQE of 9.25%is achieved,which is successfully demonstrated in a visible light communication system for voice signal transmission.We pave the way for achieving highly efficient pure-blue Pe LEDs with great application potential in future optical communication networks.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB4200400National Natural Science Foundation of China,Grant/Award Numbers:52172048,52103221,22205130,12175298+3 种基金Shandong Provincial Natural Science Foundation,Grant/Award Numbers:ZR2021QB024,ZR2021QB179,ZR2021ZD06,2023HWYQ-026Qingdao New Energy Shandong Laboratory Open Project,Grant/Award Number:QNESL OP 202309Guangdong Natural Science Foundation of China,Grant/Award Numbers:2023A1515012323,2023A1515010943,2022A1515110643,2024A1515010023Fundamental Research Funds of Shandong University。
文摘Side-chain symmetry-breaking strategy plays an important role in developing photovoltaic materials for high-efficiency all-small-molecule organic solar cells(ASM OSCs).However,the power conversion efficiencies(PCEs)of ASM OSCs still lag behind their polymer-based counterparts,which can be attributed to the difficulties in achieving favorable morphology.Herein,two asymmetric porphyrin-based donors named DAPor-DPP and DDPor-DPP were synthesized,presenting stronger intermolecular interaction and closer molecular stacking compared to the symmetric ZnP-TEH.The DAPor-DPP:6TIC blend afforded a favorablemorphologywith nanoscale phase separation and more ordered molecular packing,thus achievingmore efficient charge transportation and suppressed charge recombination.Consequently,the DAPor-DPP:6TIC-based device exhibited superior photovoltaic parameters,yielding a champion PCE of 16.62%higher than that of the DDPor-DPP-based device(14.96%).To our knowledge,16.62%can be ranked as one of the highest PCE values among the binary ASM OSC filed.Thiswork provides a prospective approach to address the challenge ofASM OSCs in improving film morphology and further achieving high efficiency via side-chain symmetry-breaking strategy,exhibiting great potential in constructing efficient ASM OSCs.
基金National Natural Science Foundation of China,Grant/Award Numbers:52203225,52073122,22375077,22008184Key R&D Project of Hubei Province,Grant/Award Number:2022BAA095+3 种基金Hubei Natural Science Foundation,Grant/Award Number:2022CFB903Special Project from Jianghan University,Grant/Award Number:2022XKZX02Ministry of Science and Technology of China,Grant/Award Number:2021YFE0113600Excellent Discipline Cultivation Project by JHUN,Grant/Award Numbers:2023XKZ010,2023XKZ014。
文摘Exciton binding energy(E_(b))has been regarded as a critical parameter in charge separation during photovoltaic conversion.Minimizing the E_(b) of the photovoltaic materials can facilitate the exciton dissociation in low-driving force organic solar cells(OSCs)and thus improve the power conversion efficiency(PCE);nevertheless,diminishing the E_(b) with deliberate design principles remains a significant challenge.Herein,bulky side chain as steric hindrance structure was inserted into Y-series acceptors to minimize the E_(b) by modulating the intra-and intermolecular interaction.Theoretical and experimental results indicate that steric hindrance-induced optimal intra-and intermolecular interaction can enhance molecular polarizability,promote electronic orbital overlap between molecules,and facilitate delocalized charge trans-fer pathways,thereby resulting in a low E_(b).The conspicuously reduced E_(b) obtained in Y-ChC5 with pinpoint steric hindrance modulation can minimize the detrimental effects on exciton dissociation in low-driving-force OSCs,achieving a remarkable PCE of 19.1%with over 95%internal quantum efficiency.Our study provides a new molecular design rationale to reduce the E_(b).
基金The authors are deeply grateful to the National Natural Science Foundation of China(21502205,51773220,51703104,and 51873227)DICP&QIBEBT(UN201805)for financial support.X.C.B.deeply thanks the Youth Innovation Promotion Association CAS(2016194).R.Q.Y.gives thanks to the“Chutian Scholar Program”of Hubei province.The work is also supported by the Dalian National Laboratory for Clean Energy for Clean Energy(DNL),CAS.The authors thanks Prof.Chunming Yang from the Shanghai Synchrotron Radiation Facility for useful discussions.
文摘To clearly show how important the impact of side chains on organic solar cells(OSCs)is,we designed three acceptors IDIC-CxPh(x=4,5,or 6)via subtle side-chain regulation.Despite this small change,significant distinctions were detected.IDIC-C4Ph devices achieve an optimal efficiency of 13.94%under thermal annealing,but thermal-assistant solvent-vapor annealing hugely suppresses the efficiencies to 10%.However,the C6Ph side chain endows extremely disordered stacking orientations,generating moderate efficiencies of~12.50%.Excitingly,the IDIC-C5Ph affords an unexpected two-channel p-p charge transport(TCCT)property,boosting the fill factor(FF)by up to 80.02%and efficiency to 14.56%,ranking the best among five-ring fused-ladder-type acceptors.Impressively,the special TCCT behavior of IDIC-C5Ph enables 470 nm thick-film OSC with a high FF of up to 70.12%and efficiency of 13.01%,demonstrating the great promise in fabricating largescale OSCs.
基金supported by the National Natural Science Foundation of China(51173199,51211140346,61405209)the National Basic Research Program of China(2014CB643501,2010DFA52310)+1 种基金the Shandong Provincial Natural Science Foundation(ZR2011BZ007)the Qingdao Municipal Science and Technology Program(11-2-4-22-hz)
文摘A new star-shaped small molecule named TCNR3TTPA,with a triphenylamine(TPA)unit as the central building block and2-(1,1-dicyanomethylene)-3-octyl rhodanine(CNR)as the end-capped group,has been designed and synthesized.TCNR3TTPA showed a deep highest occupied molecular orbital(HOMO)energy level( 5.60 e V)and broad absorption.The solution-processed bulk heterojunction(BHJ)solar cells based on TCNR3TTPA:PC61BM(1:1,w/w)exhibited a high open-circuit voltage(Voc)of 0.99 V,a short-circuit current density(Jsc)of 5.76 m A/cm2,and a power conversion efficiency(PCE)of 2.50%under the illumination of AM 1.5 G,100 m W/cm2.The high Voc is ascribed to the strong electron-with-drawing ability of the end-capped 2-(1,1-dicyanomethylene)-3-octyl rhodanine group.These results demonstrated that the Voc of small-molecule organic solar cells could be increased by introducing a strong electron-withdrawing end-capped block,and that this is an effective strategy to design high-performance small molecules for organic solar cells.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.51973169,51703172,and 52273195)Key R&D Program of Hubei Province(No.2022BAA095)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015).
文摘Single perylene diimide(PDI)used as a non-fullerene acceptor(NFA)in organic solar cells(OSCs)is enticing because of its low cost and excellent stability.To improve the photovoltaic performance,it is vital to narrow the bandgap and regulate the stacking behavior.To address this challenge,we synthesize soluble perylenetetracarboxylic bisbenzimidazole(PTCBI)molecules with a bulky side chain at the bay region,by replacing the widely used“swallow tail”type alkyl chains at the imide position of PDI molecules with a planar benzimidazole structure.Compared with PDI molecules,PTCBI molecules exhibit red-shifted UV–vis absorption spectra with larger extinction coefcient,and one magnitude higher electron mobility.Finally,OSCs based on one soluble PTCBI-type NFA,namely MAS-7,exhibit a champion power conversion efciency(PCE)of 4.34%,which is signifcantly higher than that of the corresponding PDI-based OSCs and is the highest PCE of PTCBI-based OSCs reported.These results highlight the potential of soluble PTCBI derivatives as NFAs in OSCs.
基金supported by the National Natural Science Foundation of China(52103213,52073122)University-Level Research Project Funding Program of Jianghan University(2022XKZX03)+2 种基金Ministry of Science and Technology of China(2021YFE0113600)Key R&D Project of Hubei Province(2022BAA095)Open Fund of State Key Laboratory of Luminescent Materials and Devices(2022-skllmd-04).
文摘The mechanical properties of bulk-heterojunction(BHJ)films play critical roles in the operational stability of flexible polymer solar cells(PSCs).In this study,the multi-scale mechanical properties of the BHJ films containing three representative electron acceptors are systematically evaluated.Interestingly,the tensile moduli of the films based on PC_(71)BM,Y6,and PRi-C39 decrease sequentially,and their fracture strain and toughness show an increasing trend.Moreover,the nanoindentation moduli of the films based on these acceptors vary in accordance with the results of tensile characterizations.Creep analyses illustrate that the occurrence of creep deformation in the PC_(71)BM,Y6,and PRi-C39-based films decrease sequentially.Contact angle tests demonstrate that the donor-acceptor interactions greatly affect the mechanical properties of these films.All results above demonstrate the effects of acceptor type on the multi-scale mechanical properties of the BHJ films,which are important for the development of reliable flexible PSCs.
文摘Objective::Data comparing the outcomes of MiStent(Micell Technologies,Durham,North Carolina,USA)microcrystalline biodegradable polymer(BP)drug-eluting stent(DES)and those of another post-marketing BP-DES,TIVOLI(EssenTech,Beijing,China)are rare.This study sought to compare the angiographic efficacy and clinical outcomes of the microcrystalline BP sirolimus-eluting stent(SES)system MiStent and those of TIVOLI BP-SES.Methods::The DESSOLVE-C trial was a prospective,single-blinded,multicenter,randomized trial(NCT02448524),which randomly assigned patients with de novo coronary lesions to receive MiStent or TIVOLI BP-SES by a 1:1 ratio.The primary endpoint was a non-inferiority comparison of in-stent late lumen loss(LLL)by quantitative coronary angiography at 9 months.The secondary endpoint was device-related clinical cardiovascular composite events(target lesion failure(TLF),composite of cardiac death,target vessel myocardial infarction(MI),and clinically driven target lesion revascularization)and 1-year outcomes.Results::A total of 428 patients(216 patients in the MiStent group and 212 patients in the TIVOLI group)were enrolled and included in an intention-to-treat analysis.MiStent was not only non-inferior but superior to TIVOLI for in-stent LLL at 9 months((0.23±0.37)mm vs.(0.34±0.48)mm,P for non-inferiority<0.001,P for superiority=0.02).Although without significant difference,the rate of TLF in MiStent was quantitatively lower than that in TIVOLI(3.70%vs.6.60%;P=0.17).Conclusion::Compared with TIVOLI BP-SES,the MiStent system was superior in in-stent LLL at 9 months and had a comparable clinical benefit at 1 year in de novo coronary lesions.
基金supported by the National Natural Science Foundation of China(52003209,51973169,52273195)Key R&D program of Hubei Province(2022BAA095)+1 种基金Open Key Fund Project of State Key Laboratory of Advanced Technology for Materials Synthesis and Processing of Wuhan University of Technology(2022-KF-34)Scientific Research Foundation of Wuhan Institute of Technology(K202023).
文摘Constructing the low-cost,high-efficiency,and good batch-to-batch reproducibility polymer donor is vitally important for the application of organic solar cells.Herein,we develop a structurally simple carboxylate-substituted thiazole as an electronwithdrawing building block to construct a low-cost polymer,PBTTzE,containing a facilely prepared chlorinated benzo[1,2-b:4,5-b′]dithiophene(BDTCl)donor unit.Benefiting from synergistic electron deficient effects of chlorination and ester group and C=N,as well as the noncovalent interaction of S…O and S…N,PBTTzE exhibits a deep HOMO energy level(−5.59 eV),and a planar skeleton structure.When combined with the IT-4F acceptor,the polymer(54 kDa)demonstrated a champion PCE of 15.87%,which is the highest value in the IT-4F-based binary devices to date.Moreover,PBTTzE exhibits excellent batch-tobatch reproducibility due to its very similar PCEs within a range of 43–76 kDa.In addition,an alloyed state and complementary absorption can be formed between PM6 and PBTTzE.Therefore,in a ternary device with PBTTzE added to the PM6:BTP-eC9 blend,a top PCE of 18.76%is achieved due to the suppressed energy loss,prolonged exciton diffusion distance,and improved charge transport.Our work demonstrates that the carboxylate-substituted thiazole is a highly promising acceptor unit for constructing low-cost and high-performance polymers.
基金financially supported by China Agriculture Research System(Grant No.CARS-02)Chongqing Science and Technology Bureau Agricultural High Tech Special Project(Grant No.CSTC2019ngzx0017).
文摘Currently,friction characteristics obtained from empirical parameters or soil direct shear tests are widely applied in the resistance calculation and operational parameter optimization of soil tillage components.However,the operation of soiltouching components is a dynamic process,and there are few reports on the dynamic friction characteristics of soil-contacting components in agricultural tillage based on factors such as different moisture content,pressure,and relative velocity.Herein,a test device to measure the friction characteristics of compressible bulk materials was developed:the interface friction between the soil and 65Mn plate and the internal friction characteristics of soil were tested using this device,and the dynamic changes of interface friction coefficient and internal friction coefficient with moisture content,pressure,and relative velocity were obtained.Based on the dynamic friction parameters of soil,the ditching resistance model of a typical ploughshare opener was established,the ditching resistance value was predicted,and field experiments were performed under different operating speeds(0.5 m/s,0.7 m/s,and 0.9 m/s)and ditching depths(60 mm,100 mm,and 140 mm).The results indicated that the calculated values of the ditching resistance model based on the dynamic friction parameters of soil reduced the error by 15%compared with the calculated values based on the friction characteristics of the soil direct shear test,which verified the accuracy of the ditching resistance model and the validity of the parameters obtained from the test device for the friction characteristics of compressible bulk materials.In addition,the minimum ditching resistance can be obtained when the ditching speed is 0.7 m/s at the same ditching depths,which is consistent with the dynamic friction characteristics of soil.It can be found that the dynamic friction characteristics of bulk materials have basic theoretical support for the optimization of operational component structures and operational parameters.
