Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the s...Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the surface modification of Li_(2)TiSiO_(5) is carried out at different temperatures using low-temperature plasma to enhance its lithium storage performance.The morphological structure and electrochemical tests demonstrate that plasma treatment can improve the degree of agglomeration.The peak position of the plasma-treated Li_(2)TiSiO_(5) is shifted to a lower angle,and the shift angle increases with increasing sputtering power.Li_(2)TiSiO_(5) after 300 W bombardment shows excellent capacity(144.7 mA·hg^(−1)after 500 cycles at 0.1 Ag^(−1))and rate performance(140 mA·hg^(−1)at 5 Ag^(−1)).Electrochemical analysis indicates that excellent electrochemical performance is attributed to the enhancement of electronic and ionic conductivity by plasma bombardment.展开更多
Prophages are temperate phages integrated into the host bacterial genome.They play an important role in the adaptation and the pathogenicity of bacteria,especially pathogenic bacteria.In this review,we described the d...Prophages are temperate phages integrated into the host bacterial genome.They play an important role in the adaptation and the pathogenicity of bacteria,especially pathogenic bacteria.In this review,we described the distribution of prophages in different hosts and different environments,and focused on the significance of prophages.At the singlecell level,prophages can help the host adapt to harsh external environments by directly carrying virulence genes,encoding regulatory factors and activating lysogeny.At the population level,prophages can influence the overall evolutionary direction and ecological function of the host bacterial community.This review will help us understand the important role of prophages as unique organisms in individual bacteria and microbial populations.展开更多
Silver nanowires(AgNWs),as promising conductor materials,have found their application in various stretchable electronics.However,the mismatch between the work function of AgNWs electrodes and energy level of semicondu...Silver nanowires(AgNWs),as promising conductor materials,have found their application in various stretchable electronics.However,the mismatch between the work function of AgNWs electrodes and energy level of semiconductors limits the obtaining of high-performance devices,especially in stretchable p-type organic thin film transistors(OTFTs)where the resulting severe injection barrier significantly lowers the overall performance of the devices.In this study,we prepared stretchable AgNWs electrodes with high work function that closely matched the highest occupied molecular orbital(HOMO)of the p-type polymer semiconductor poly(indacenodithiophene-co-benzothiadiazole)(IDT-BT)via a ligand exchange reaction with fluorinated molecules and post-treatment-free fabrication.In comparison to the commercial polyvinylpyrrolidone(PVP)stabilized AgNWs,electrodes based on ligand-exchanged AgNWs exhibited higher work function over 5 eV,closer to the HOMO of IDT-BT.As a result,IDT-BT-based p-type OTFTs fabricated using ligand-exchanged AgNWs electrodes achieved a reduced threshold voltage and improved carrier transport property,with a hole mobility of 0.4 cm^(2) V^(-1) s^(-1).Moreover,the ligand exchange on the surface of AgNWs caused no deterioration of the deformability of the resulting devices,largely retaining the original mobility after being stretched by 30%strain.These results demonstrate the effectiveness of the work function tuning via the ligand-exchange strategy in the processing of AgNWs electrodes for enhancing the performance of stretchable electronics.展开更多
The investigation of n-type doping holds a significant interest for the application of thermoelectrics.Herein,the doping of an indandione-terminated compound Q-4F with a singlet open-shell ground state was studied usi...The investigation of n-type doping holds a significant interest for the application of thermoelectrics.Herein,the doping of an indandione-terminated compound Q-4F with a singlet open-shell ground state was studied using two n-dopants N-DMBI and LCV.Both of these two dopants can effectively dope Q-4F due to the large offset between the singly occupied molecular orbital(SOMO)of dopants and the lowest unoccupied molecular orbital(LUMO)of Q-4F.N-DMBI has a higher doping ability than LCV as demonstrated by the UV-vis-NIR and EPR measurements.However,in comparison to N-DMBI doped Q-4F,LCV doped system exhibits much higher electrical conductivity and power factor due to its unperturbed molecular packing and favorable morphology after doping.The optimal conductivity of LCV doped Q-4F is 7.16×10^(-2)±0.16 S·cm^(-1) and the highest power factor reaches 12.3±0.85μW·m–1·K^(-2).These results demonstrate that the modulation of n-dopants is a powerful strategy to balance the doping efficiency and microstructure toward a maximum thermoelectric performance.展开更多
Natural perceptual systems,shaped by millions of years of evolution,exhibit unparalleled environmental adaptability and energy-efficient information processing that surpass existing engineering technologies[[1],[2],[3...Natural perceptual systems,shaped by millions of years of evolution,exhibit unparalleled environmental adaptability and energy-efficient information processing that surpass existing engineering technologies[[1],[2],[3]].Particularly,the avian visual system of raptors-especially eagles has emerged as a paradigm for bioinspired optoelectronics,owing to its integrated multispectral sensing,dynamic range modulation,and hierarchical neural processing[4].展开更多
Interfacial engineering at the dielectric/semiconductor interface is highly crucial for fabricating organic field-effect transistors with high performance.In this study,a bilayer MXene/semiconductor configuration is i...Interfacial engineering at the dielectric/semiconductor interface is highly crucial for fabricating organic field-effect transistors with high performance.In this study,a bilayer MXene/semiconductor configuration is introduced to fabricate a high-performance n-type transistor,where electrical charges are formed and modulated at the SiO/semiconductor interface,and MXene nanosheets serve as the primary electrical charge channel due to their high mobility and long lateral size.The electrical performance is optimized by adjusting the degree of connectivity of the MXene nanosheets.The proposed MXene/poly{[N,N’-bis(2-octyl-dodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5’-(2,2’-bithiophene)}(N2200)transistors show boosted ntype characteristics,including a 100-fold increase in field-effect mobility,a large ON/OFF ratio of 10^(4),and a small subthreshold swing of 0.65 V dec^(-1),all of which are significantly improved compared with single-layer N2200 transistors.The high performance of the two-dimensional MXene nanochannel is due to its electronegativity and high mobility.The electronegativity significantly enhances electron transfer from N2200 to the MXene channel,where they are efficiently transported along the MXene channel.Interestingly,the MXene/p-type semiconductor transistors show suppressed ptype performance because of the highly negative MXene nanosheets.Additionally,the proposed bilayer MXene/n-type semiconductor configuration shows a good configuration generality and improved performance.These findings demonstrate the feasibility of fabricating high-performance ntype transistors using a bilayer MXene/semiconductor combination.展开更多
Polythiophenes,with merits of low cost and high scalability of synthesis,have received growing interest in organic solar cells.To date,the best-performing polythiophene:nonfullerene solar cells exhibit typical power c...Polythiophenes,with merits of low cost and high scalability of synthesis,have received growing interest in organic solar cells.To date,the best-performing polythiophene:nonfullerene solar cells exhibit typical power conversion efficiencies (PCEs) of 10%–12%,which is much lower than those employing PM6-and D18-type polymers.This inferior performance is mostly limited by the improper miscibility between polythiophene and acceptors.Efforts on engineering the molecular structure to systematically tune the miscibility are required.With the aid of group contribution calculations,the miscibility of polythiophene:nonfullerene blend system was finely tuned by varying the ratios of siloxane-terminated chains and alkyl chains in ester-substituted polythiophenes through random copolymerization.Based on a series of the polythiophene and nonfullerene acceptors,the detailed analysis of blend miscibility and performance reveals a surprising anticorrelation between the Flory-Huggins interaction parameter (χ_(aa)) and the optimal time of solvent vapor annealing for device performance across these systems.Primarily due to the slightly higher χ_(aa),the blend of PDCBT-Cl-Si5 and ITIC-Th1 results in a record-high PCE of 12.85%in polythiophene:nonfullerene solar cells.The results not only provide a calculation-guided approach for molecular design but also prove that precise control of the miscibility is an effective way to design high-performance polythiophene:nonfullerene blends and beyond.展开更多
Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels...Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels and planar conjugated backbones.Herein,three CPs have been synthesized by copolymerizing an indandione-terminated quinoidal unit with bithiophene derivatives.Owning to the high electron affinity of the indandione-terminated quinoidal unit,all polymers showed deep LUMO energy levels below-4.10 eV.Incorporating electron-withdrawing substituents(F or CN)on the bithiophene comonomer can further downshift the LUMO energy levels.As a result,a more efficient n-doping process can be realized when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine(N-DMBI)as the dopant.Ultimately,the polymer with CN substituents delivered the best thermoelectric performance with a power factor of up to 2.14μW·m^(−1)·K^(−2),because it possessed the lowest LUMO energy level among the three CPs.This work highlights that the modulation of LUMO energy level is an effective strategy to optimize the thermoelectric performance of CPs.展开更多
Record-breaking organic solar cells(OSCs)based on blends of polymer donors and small molecule acceptors often show undesirable degradati on,which severely precludes their practical use.Herei n,we demonstrate a facile ...Record-breaking organic solar cells(OSCs)based on blends of polymer donors and small molecule acceptors often show undesirable degradati on,which severely precludes their practical use.Herei n,we demonstrate a facile and cost-effective approach to con struct thermally stable OSCs at 150℃ by incorporating a small amount of a polymer insulator polyacenaphthylene(PAC)with high glass-transition temperature over 230℃ into polymer:acceptor blends.The model PTB7-Th:EH-IDTBR blend with 10 wt%PAC maintained above 85%of its initial efficiency upon continuous heating at 150℃ for over 800 h,while the efficiency of the blend without PAC sharply dropped by 70%after-300 h.Owing to high miscibility with acceptors,PAC confines the motion of the acceptor molecules and suppresses the acceptor crystallization at elevated temperatures,leading to significantly improved stability.Importantly,the effectiveness of this blending approach was also validated in many other OSC systems,showing great potential for achieving high-performance thermally stable electronics.展开更多
The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylen...The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylenimine ethoxylated(PEIE)modified organic field-effect transistors(OFETs)is reported.The intrinsic quinoidal characteristic and excellent coplanarity of BDP can lower the lowest unoccupied molecular orbital(LUMO)levels and improve ordered interchain packing of the resulting polymers in solid states,which are favorable for electron-injection and transport.By using PEIE as the interlayer to block the hole injection,unipolar n-type transport characteristics with high electron mobility of 0.58 and 1.01 cm^(2) V^(-1)s^(-1)were achieved by the OFETs based on PBDP-2F and PBDP-2CN,respectively.More importantly,the extracted mobilities are highly reliable with the reliability factor of above 80%.To the best of our knowledge,PBDP-2CN is the very first quinoid-based conjugated polymer with reliable electron mobility exceeding 1 cm^(2) V^(-1)s^(-1).This work represents a significant step in exploring intrinsic quinoidal CPs for application in n-channel OFETs and logic complementary circuits.展开更多
Organic dyes with strong absorption in the second near-infrared(NIR-II)window(1000-1700 nm)have multiple applications.However,the design and synthesis of stable NIR-II absorbing organic dyes are very challenging and c...Organic dyes with strong absorption in the second near-infrared(NIR-II)window(1000-1700 nm)have multiple applications.However,the design and synthesis of stable NIR-II absorbing organic dyes are very challenging and constantly defy our synthetic ability.In this work,we have successfully synthesized a series of soluble and stable fused thienoisoindigo(nThIID)ribbons.The absorption maximum(λ_(max))of the ribbons increases from 644 nm of 1ThIID to 1252 nm of 6ThIID.Importantly,nThIIDs with n≥4 all display strong absorption in the NIR-II window with molar extinction coefficients(ε_(max))greater than 105 L mol^(−1)cm^(−1)atλmax.These molecules are promising photothermal conversion dyes with photothermal conversion efficiencies of ca.60%under 1064 nm laser irradiation.展开更多
Donor-acceptor （D-A）-conjugated polymers P（BT-C1） and P（BT-C2）, with dithieno[2,3-b;7,6-b]carbazole （C1） or dithi- eno[3,2-b;6,7-b]carbazole （C2） as D-unit and benzothiadiazole （BT） as A-unit, were synthes...Donor-acceptor （D-A）-conjugated polymers P（BT-C1） and P（BT-C2）, with dithieno[2,3-b;7,6-b]carbazole （C1） or dithi- eno[3,2-b;6,7-b]carbazole （C2） as D-unit and benzothiadiazole （BT） as A-unit, were synthesized. The optical bandgaps of the polymers are similar （1.84 and 1.88 eV, respectively）. The structures of donor units noticeably influence the energy levels and backbone curvature of the polymers. P（BT-C1） shows a large backbone curvature; its highest occupied molecular orbital （HOMO） energy level is -5.18 eV, whereas P（BT-C2） displays a pseudo-straight backbone and has a HOMO energy level of -5.37 eV. The hole mobilities of the polymers without thermal annealing are 1.9×10^-3 and 2.7×10^-3 cm^2 V-1 s^-1 for P（BT-C1） and P（BT-C2）, respectively, as measured by organic thin-film transistors （OTFTs）. Polymer solar cells using P（BT-C1） and P（BT-C2） as the donor and phenyl-Cyl-butyric acid methyl ester （PCyLBM） as the acceptor were fabricated. Power conversion efficiencies （PCEs） of 4.9% and 5.0% were achieved for P（BT-C1） and P（BT-C2）, respectively. The devices based on P（BT-C2） exhibited a higher Voc due to the deeper HOMO level of the polymer, which led to a slightly higher PCE.展开更多
Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydr...Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.展开更多
The neuromorphic vision sensor(NeuVS),which is based on organic field-effect transistors(OFETs),uses polar functional groups(PFGs)in polymer dielectrics as interfacial units to control charge carriers.However,the mech...The neuromorphic vision sensor(NeuVS),which is based on organic field-effect transistors(OFETs),uses polar functional groups(PFGs)in polymer dielectrics as interfacial units to control charge carriers.However,the mechanism of modulating charge transport on basis of PFGs in devices is unclear.Here,the carboxyl group is introduced into polymer dielectrics in this study,and it can induce the charge transfer process at the semiconductor/dielectric interfaces for effective carrier transport,giving rise to the best device mobility up to 20 cm^(2) V^(−1) s^(−1) at a low operating voltage of−1 V.Furthermore,the polarity modulation effect could further increase the optical figures of merit in NeuVS devices by at least an order of magnitude more than the devices using carboxyl group-free polymer dielectrics.Additionally,devices containing carboxyl groups improved image sensing for light information decoding with 52 grayscale signals and memory capabilities at an incredibly low power consumption of 1.25 fJ/spike.Our findings provide insight into the production of high-performance polymer dielectrics for NeuVS devices.展开更多
The design and synthesis of high-mobility n-type near-amorphous conjugated polymers(NACPs)represent a prominent research focus in organic semiconductors.The diketopyrrolopyrrole(DPP)unit is a widely used building bloc...The design and synthesis of high-mobility n-type near-amorphous conjugated polymers(NACPs)represent a prominent research focus in organic semiconductors.The diketopyrrolopyrrole(DPP)unit is a widely used building block for constructing high-mobility conjugated polymers.However,DPP-based polymers often exhibit semi-crystalline structures and inherent p-type charge-transport characteristics,which hinder their application in n-type flexible electronic devices.To overcome these challenges,this study employs acceptor modulation and terpolymerization by integrating pyridine-flanked DPP with 3,4-difluorothiophene(2FT)and selenophene(Se)as comonomers.Besides,the incorporation of oligo(ethylene glycol)side chains is strategically designed to enhance polymer solubility and favorably modulate the morphology.Thus,a series of polymers,P2FTx(x=100–0),are synthesized via Stille polycondensation,enabling systematic investigation of the composition-structure-property relationships.It reveals that optimal Se incorporation minimizes torsional barriers and reduces backbone regularity,inducing a near-amorphous phase with locally ordered domains while maintaining suitable energy levels for efficient electron transport.Notably,P2FT90 achieves the highest electron mobility of 0.47 cm^(2)·V^(-1)·s^(-1),highlighting the efficacy of this compositional engineering approach.This study exemplifies a synergistic approach that combines precise control of backbone regioregularity and energy-level engineering to realize high-performance n-type NACPs.展开更多
基金supported by Changzhou Basic Research Program(No.CJ20235030)the Research Initiation Fund of Changzhou University(No.ZMF23020057).
文摘Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the surface modification of Li_(2)TiSiO_(5) is carried out at different temperatures using low-temperature plasma to enhance its lithium storage performance.The morphological structure and electrochemical tests demonstrate that plasma treatment can improve the degree of agglomeration.The peak position of the plasma-treated Li_(2)TiSiO_(5) is shifted to a lower angle,and the shift angle increases with increasing sputtering power.Li_(2)TiSiO_(5) after 300 W bombardment shows excellent capacity(144.7 mA·hg^(−1)after 500 cycles at 0.1 Ag^(−1))and rate performance(140 mA·hg^(−1)at 5 Ag^(−1)).Electrochemical analysis indicates that excellent electrochemical performance is attributed to the enhancement of electronic and ionic conductivity by plasma bombardment.
基金the National Natural Science Foundation(31600148)the Shandong Excellent Young Scientist Award Fund(BS2014YY031).
文摘Prophages are temperate phages integrated into the host bacterial genome.They play an important role in the adaptation and the pathogenicity of bacteria,especially pathogenic bacteria.In this review,we described the distribution of prophages in different hosts and different environments,and focused on the significance of prophages.At the singlecell level,prophages can help the host adapt to harsh external environments by directly carrying virulence genes,encoding regulatory factors and activating lysogeny.At the population level,prophages can influence the overall evolutionary direction and ecological function of the host bacterial community.This review will help us understand the important role of prophages as unique organisms in individual bacteria and microbial populations.
基金supported by the National Natural Science Foundation of China(52173179,52433008 and 52121002)the Fundamental Research Funds for the Central Universities.
文摘Silver nanowires(AgNWs),as promising conductor materials,have found their application in various stretchable electronics.However,the mismatch between the work function of AgNWs electrodes and energy level of semiconductors limits the obtaining of high-performance devices,especially in stretchable p-type organic thin film transistors(OTFTs)where the resulting severe injection barrier significantly lowers the overall performance of the devices.In this study,we prepared stretchable AgNWs electrodes with high work function that closely matched the highest occupied molecular orbital(HOMO)of the p-type polymer semiconductor poly(indacenodithiophene-co-benzothiadiazole)(IDT-BT)via a ligand exchange reaction with fluorinated molecules and post-treatment-free fabrication.In comparison to the commercial polyvinylpyrrolidone(PVP)stabilized AgNWs,electrodes based on ligand-exchanged AgNWs exhibited higher work function over 5 eV,closer to the HOMO of IDT-BT.As a result,IDT-BT-based p-type OTFTs fabricated using ligand-exchanged AgNWs electrodes achieved a reduced threshold voltage and improved carrier transport property,with a hole mobility of 0.4 cm^(2) V^(-1) s^(-1).Moreover,the ligand exchange on the surface of AgNWs caused no deterioration of the deformability of the resulting devices,largely retaining the original mobility after being stretched by 30%strain.These results demonstrate the effectiveness of the work function tuning via the ligand-exchange strategy in the processing of AgNWs electrodes for enhancing the performance of stretchable electronics.
基金supported by the National Key R&D Program of China(2021YFA0717900)the National Natural Science Foundation of China(Nos.22222506,52073209,and 52121002)and the Fundamental Research Funds for the Central Universities.
文摘The investigation of n-type doping holds a significant interest for the application of thermoelectrics.Herein,the doping of an indandione-terminated compound Q-4F with a singlet open-shell ground state was studied using two n-dopants N-DMBI and LCV.Both of these two dopants can effectively dope Q-4F due to the large offset between the singly occupied molecular orbital(SOMO)of dopants and the lowest unoccupied molecular orbital(LUMO)of Q-4F.N-DMBI has a higher doping ability than LCV as demonstrated by the UV-vis-NIR and EPR measurements.However,in comparison to N-DMBI doped Q-4F,LCV doped system exhibits much higher electrical conductivity and power factor due to its unperturbed molecular packing and favorable morphology after doping.The optimal conductivity of LCV doped Q-4F is 7.16×10^(-2)±0.16 S·cm^(-1) and the highest power factor reaches 12.3±0.85μW·m–1·K^(-2).These results demonstrate that the modulation of n-dopants is a powerful strategy to balance the doping efficiency and microstructure toward a maximum thermoelectric performance.
基金supported by the National Key Research and Development Program of China(2021YFA0717900)the National Natural Science Foundation of China(52273190 and 52121002).
文摘Natural perceptual systems,shaped by millions of years of evolution,exhibit unparalleled environmental adaptability and energy-efficient information processing that surpass existing engineering technologies[[1],[2],[3]].Particularly,the avian visual system of raptors-especially eagles has emerged as a paradigm for bioinspired optoelectronics,owing to its integrated multispectral sensing,dynamic range modulation,and hierarchical neural processing[4].
基金supported by the National Natural Science Foundation of China(U21A20497 and 61974029)the Natural Science Foundation for Distinguished Young Scholars of Fujian Province(2020J06012)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ129)。
文摘Interfacial engineering at the dielectric/semiconductor interface is highly crucial for fabricating organic field-effect transistors with high performance.In this study,a bilayer MXene/semiconductor configuration is introduced to fabricate a high-performance n-type transistor,where electrical charges are formed and modulated at the SiO/semiconductor interface,and MXene nanosheets serve as the primary electrical charge channel due to their high mobility and long lateral size.The electrical performance is optimized by adjusting the degree of connectivity of the MXene nanosheets.The proposed MXene/poly{[N,N’-bis(2-octyl-dodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5’-(2,2’-bithiophene)}(N2200)transistors show boosted ntype characteristics,including a 100-fold increase in field-effect mobility,a large ON/OFF ratio of 10^(4),and a small subthreshold swing of 0.65 V dec^(-1),all of which are significantly improved compared with single-layer N2200 transistors.The high performance of the two-dimensional MXene nanochannel is due to its electronegativity and high mobility.The electronegativity significantly enhances electron transfer from N2200 to the MXene channel,where they are efficiently transported along the MXene channel.Interestingly,the MXene/p-type semiconductor transistors show suppressed ptype performance because of the highly negative MXene nanosheets.Additionally,the proposed bilayer MXene/n-type semiconductor configuration shows a good configuration generality and improved performance.These findings demonstrate the feasibility of fabricating high-performance ntype transistors using a bilayer MXene/semiconductor combination.
基金supported by the National Natural Science Foundation of China(52073207,22075200,51703158,51933008)supported by the Peiyang Scholar Program of Tianjin University+2 种基金the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology,2020skllmd-11)Peiyang Young Junior Faculty Program of Tianjin University(2019XRG-0021)Independent Innovation Fund of Tianjin University(2020XZC-0105)。
文摘Polythiophenes,with merits of low cost and high scalability of synthesis,have received growing interest in organic solar cells.To date,the best-performing polythiophene:nonfullerene solar cells exhibit typical power conversion efficiencies (PCEs) of 10%–12%,which is much lower than those employing PM6-and D18-type polymers.This inferior performance is mostly limited by the improper miscibility between polythiophene and acceptors.Efforts on engineering the molecular structure to systematically tune the miscibility are required.With the aid of group contribution calculations,the miscibility of polythiophene:nonfullerene blend system was finely tuned by varying the ratios of siloxane-terminated chains and alkyl chains in ester-substituted polythiophenes through random copolymerization.Based on a series of the polythiophene and nonfullerene acceptors,the detailed analysis of blend miscibility and performance reveals a surprising anticorrelation between the Flory-Huggins interaction parameter (χ_(aa)) and the optimal time of solvent vapor annealing for device performance across these systems.Primarily due to the slightly higher χ_(aa),the blend of PDCBT-Cl-Si5 and ITIC-Th1 results in a record-high PCE of 12.85%in polythiophene:nonfullerene solar cells.The results not only provide a calculation-guided approach for molecular design but also prove that precise control of the miscibility is an effective way to design high-performance polythiophene:nonfullerene blends and beyond.
基金supported by National Key R&D Program of China(2021YFA0717900)National Natural Science Foundation of China(52073209,52121002 and 22222506)the Fundamental Research Funds forthe Central Universities.
文摘Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels and planar conjugated backbones.Herein,three CPs have been synthesized by copolymerizing an indandione-terminated quinoidal unit with bithiophene derivatives.Owning to the high electron affinity of the indandione-terminated quinoidal unit,all polymers showed deep LUMO energy levels below-4.10 eV.Incorporating electron-withdrawing substituents(F or CN)on the bithiophene comonomer can further downshift the LUMO energy levels.As a result,a more efficient n-doping process can be realized when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine(N-DMBI)as the dopant.Ultimately,the polymer with CN substituents delivered the best thermoelectric performance with a power factor of up to 2.14μW·m^(−1)·K^(−2),because it possessed the lowest LUMO energy level among the three CPs.This work highlights that the modulation of LUMO energy level is an effective strategy to optimize the thermoelectric performance of CPs.
基金supported by the National Natural Science Foundation of China(Nos.52073207,22075200,and 51703158)L.Y.expresses thanks for the start-up grant of Peiyang Scholar program from Tianjin University and the Open Fund of the State Key Laboratory of Luminesce nt Materials and Devices(South China University of Technology,No.2020-skllmd-11)+1 种基金M.L.thanks the Peiyang Young Junior Faculty Program of Tianjin University(No.2019XRG-0021)L.Y.acknowledges the merit beamtime(Project ID:15692)approved by the Australian Synchrotron and beamtime(Project ID:2020-BEPC-PT-004082)approved by Beijing Synchro-tron Radiati on Facility.
文摘Record-breaking organic solar cells(OSCs)based on blends of polymer donors and small molecule acceptors often show undesirable degradati on,which severely precludes their practical use.Herei n,we demonstrate a facile and cost-effective approach to con struct thermally stable OSCs at 150℃ by incorporating a small amount of a polymer insulator polyacenaphthylene(PAC)with high glass-transition temperature over 230℃ into polymer:acceptor blends.The model PTB7-Th:EH-IDTBR blend with 10 wt%PAC maintained above 85%of its initial efficiency upon continuous heating at 150℃ for over 800 h,while the efficiency of the blend without PAC sharply dropped by 70%after-300 h.Owing to high miscibility with acceptors,PAC confines the motion of the acceptor molecules and suppresses the acceptor crystallization at elevated temperatures,leading to significantly improved stability.Importantly,the effectiveness of this blending approach was also validated in many other OSC systems,showing great potential for achieving high-performance thermally stable electronics.
基金supported by the Ministry of Science and Technology of China(2017YFA0206600,2019YFA0705900)the National Natural Science Foundation of China(21875072,21774093)+2 种基金the Fundamental Research Funds for Central Universities(South China University of Technology,D2190310)Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08L075)the Open Funds of State Key Laboratory of Fine Chemicals(KF1901)。
文摘The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylenimine ethoxylated(PEIE)modified organic field-effect transistors(OFETs)is reported.The intrinsic quinoidal characteristic and excellent coplanarity of BDP can lower the lowest unoccupied molecular orbital(LUMO)levels and improve ordered interchain packing of the resulting polymers in solid states,which are favorable for electron-injection and transport.By using PEIE as the interlayer to block the hole injection,unipolar n-type transport characteristics with high electron mobility of 0.58 and 1.01 cm^(2) V^(-1)s^(-1)were achieved by the OFETs based on PBDP-2F and PBDP-2CN,respectively.More importantly,the extracted mobilities are highly reliable with the reliability factor of above 80%.To the best of our knowledge,PBDP-2CN is the very first quinoid-based conjugated polymer with reliable electron mobility exceeding 1 cm^(2) V^(-1)s^(-1).This work represents a significant step in exploring intrinsic quinoidal CPs for application in n-channel OFETs and logic complementary circuits.
基金This work was supported by the National Natural Science Foundation of China(grant nos.22005211 and 52121002).Prof.Yonghao Zheng is acknowledged for his help on the analysis of VT-EPR results.
文摘Organic dyes with strong absorption in the second near-infrared(NIR-II)window(1000-1700 nm)have multiple applications.However,the design and synthesis of stable NIR-II absorbing organic dyes are very challenging and constantly defy our synthetic ability.In this work,we have successfully synthesized a series of soluble and stable fused thienoisoindigo(nThIID)ribbons.The absorption maximum(λ_(max))of the ribbons increases from 644 nm of 1ThIID to 1252 nm of 6ThIID.Importantly,nThIIDs with n≥4 all display strong absorption in the NIR-II window with molar extinction coefficients(ε_(max))greater than 105 L mol^(−1)cm^(−1)atλmax.These molecules are promising photothermal conversion dyes with photothermal conversion efficiencies of ca.60%under 1064 nm laser irradiation.
基金financially supported by the National Basic Research Program of China(2014CB643504)the National Natural Science Foundation of China(51273193)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12010300)
文摘Donor-acceptor （D-A）-conjugated polymers P（BT-C1） and P（BT-C2）, with dithieno[2,3-b;7,6-b]carbazole （C1） or dithi- eno[3,2-b;6,7-b]carbazole （C2） as D-unit and benzothiadiazole （BT） as A-unit, were synthesized. The optical bandgaps of the polymers are similar （1.84 and 1.88 eV, respectively）. The structures of donor units noticeably influence the energy levels and backbone curvature of the polymers. P（BT-C1） shows a large backbone curvature; its highest occupied molecular orbital （HOMO） energy level is -5.18 eV, whereas P（BT-C2） displays a pseudo-straight backbone and has a HOMO energy level of -5.37 eV. The hole mobilities of the polymers without thermal annealing are 1.9×10^-3 and 2.7×10^-3 cm^2 V-1 s^-1 for P（BT-C1） and P（BT-C2）, respectively, as measured by organic thin-film transistors （OTFTs）. Polymer solar cells using P（BT-C1） and P（BT-C2） as the donor and phenyl-Cyl-butyric acid methyl ester （PCyLBM） as the acceptor were fabricated. Power conversion efficiencies （PCEs） of 4.9% and 5.0% were achieved for P（BT-C1） and P（BT-C2）, respectively. The devices based on P（BT-C2） exhibited a higher Voc due to the deeper HOMO level of the polymer, which led to a slightly higher PCE.
基金This work was financially supported by the National Key R&D Program of China(2021YFA0717900)National Natural Science Foundation of China(no.51933008,22222506 and 52121002).
文摘Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.
基金They acknowledge financial support from the National Key Research and Development Program(2021YFA0717900)Beijing National Laboratory for Molecular Sciences(BNLMS202006)+1 种基金National Natural Science Foundation of China(62004138,52273190,61905121)Haihe Laboratory of Sustainable Chemical Transformations.
文摘The neuromorphic vision sensor(NeuVS),which is based on organic field-effect transistors(OFETs),uses polar functional groups(PFGs)in polymer dielectrics as interfacial units to control charge carriers.However,the mechanism of modulating charge transport on basis of PFGs in devices is unclear.Here,the carboxyl group is introduced into polymer dielectrics in this study,and it can induce the charge transfer process at the semiconductor/dielectric interfaces for effective carrier transport,giving rise to the best device mobility up to 20 cm^(2) V^(−1) s^(−1) at a low operating voltage of−1 V.Furthermore,the polarity modulation effect could further increase the optical figures of merit in NeuVS devices by at least an order of magnitude more than the devices using carboxyl group-free polymer dielectrics.Additionally,devices containing carboxyl groups improved image sensing for light information decoding with 52 grayscale signals and memory capabilities at an incredibly low power consumption of 1.25 fJ/spike.Our findings provide insight into the production of high-performance polymer dielectrics for NeuVS devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.22375051 and 52203216)the Shanghai Rising-Star Program(24YF2702800).
文摘The design and synthesis of high-mobility n-type near-amorphous conjugated polymers(NACPs)represent a prominent research focus in organic semiconductors.The diketopyrrolopyrrole(DPP)unit is a widely used building block for constructing high-mobility conjugated polymers.However,DPP-based polymers often exhibit semi-crystalline structures and inherent p-type charge-transport characteristics,which hinder their application in n-type flexible electronic devices.To overcome these challenges,this study employs acceptor modulation and terpolymerization by integrating pyridine-flanked DPP with 3,4-difluorothiophene(2FT)and selenophene(Se)as comonomers.Besides,the incorporation of oligo(ethylene glycol)side chains is strategically designed to enhance polymer solubility and favorably modulate the morphology.Thus,a series of polymers,P2FTx(x=100–0),are synthesized via Stille polycondensation,enabling systematic investigation of the composition-structure-property relationships.It reveals that optimal Se incorporation minimizes torsional barriers and reduces backbone regularity,inducing a near-amorphous phase with locally ordered domains while maintaining suitable energy levels for efficient electron transport.Notably,P2FT90 achieves the highest electron mobility of 0.47 cm^(2)·V^(-1)·s^(-1),highlighting the efficacy of this compositional engineering approach.This study exemplifies a synergistic approach that combines precise control of backbone regioregularity and energy-level engineering to realize high-performance n-type NACPs.
