Research on asymmetric A–D–A structured non-fullerene acceptors has lagged far behind the development of symmetric counterpart.In this contribution,by simply replacing one sulfur atom in indacenodithiophene unit wit...Research on asymmetric A–D–A structured non-fullerene acceptors has lagged far behind the development of symmetric counterpart.In this contribution,by simply replacing one sulfur atom in indacenodithiophene unit with a selenium atom,an asymmetric building block Se PT and a corresponding asymmetric non-fullerene acceptor Se PT-IN have been developed.Asymmetric Se PT-IN achieved a high efficiency of 10.20% in organic solar cells when blended with PBT1-C,much higher than that of symmetric TPT-IN counterpart(8.91%).Our results demonstrated an effective heteroatom substitution strategy to develop asymmetric A–D–A structured non-fullerene acceptors.展开更多
Organic solar cells based on acceptor-p-acceptor(A-π-A) electron acceptors have attracted intensive attention due to their increasing and record power conversion efficiencies. To date, almost all of the reported A-π...Organic solar cells based on acceptor-p-acceptor(A-π-A) electron acceptors have attracted intensive attention due to their increasing and record power conversion efficiencies. To date, almost all of the reported A-π-A electron acceptors are based on aromatic p structures. Here, we have investigated the impact of anti-aromatization of the p-bridges on the optoelectronic properties of A-π-A electron acceptors by(time-dependent) density functional theory. Our calculations show that besides the frontier molecular orbitals corresponding to the aromatic p-bridge based acceptors("aromatic" acceptors),additional and unique occupied and unoccupied frontier orbitals are found for the acceptors based on the anti-aromatic p-bridges("anti-aromatic" acceptors). Moreover, by tuning isomeric structures of the p-bridges(e.g., fusion orientations or linking positions of thiophene moieties), the optical excitation energies for the transition between the additional occupied and unoccupied levels turn to be close to or substantially lower with respect to those for the transition between the "aromatic" frontier orbitals. The optical absorption of the "anti-aromatic" acceptors is thus either stronger or broader than the "aromatic"acceptors. Finally, the reorganization energies for electron transport are tunable and dependent on the p-bridge structures. These results indicate a great potential of "anti-aromatic" electron acceptors in organic photovoltaics.展开更多
Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chain...Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chains on the molecular packing and electron transport properties of a series of bay-linked dimeric perylenediimide(PDI) derivatives by atomistic molecular dynamics simulations in combination with charge transfer rate theory and kinetic Monte Carlo simulations. The results show that despite of different branching positions of the alkyl chains,π–π stacking is effectively inhibited for all the dimeric PDI derivatives. As the branching position moves away from the PDI backbone, the appearance of the alkyl atoms around the PDI backbone will first decrease and then increase. Correspondingly, the short contacts between the PDI moieties are first enhanced and then reduced. In particular, when the branching position is at the third carbon atom, the intermolecular connectivity becomes the most effective and the electron mobility is significantly increased by 2 times.展开更多
Electronic polarization has an important impact on the site energies of charge carriers that play a key role in determining the charge transport in organic semiconductors.Dipolar molecules have strong intermolecular i...Electronic polarization has an important impact on the site energies of charge carriers that play a key role in determining the charge transport in organic semiconductors.Dipolar molecules have strong intermolecular interactions and widespread applications in organic optoelectronics.Howeve r,compared with nonpolar organic semiconductors,electronic polarization for dipolar systems has been rarely studied.Here,taking 1,2,3,4-tetrafluoro-6,7-dimethylnaphthalene as representative,we have calculated the electronic polarization energies of dipolar organic molecular crystals by means of a polarizable forcefield method.Surprisingly,our results point to that the polarization energies for this dipolar system are similar to those of nonpolar systems.In addition,theπ-πstack contributes only about 30%~40%to the total polarization energy,thus the polarization effects along the three dimensions should be treated equally even for the one-dimensional stacking crystals.展开更多
Organic fluorophores are indispensible in chemical/biological imaging. The conjugated fluorescent molecules simultaneously possessing highly tunable emission, high quantum yield in solvents of different polarities, an...Organic fluorophores are indispensible in chemical/biological imaging. The conjugated fluorescent molecules simultaneously possessing highly tunable emission, high quantum yield in solvents of different polarities, and large Stokes shift are quite rare. Herein, we report a new category of fluorophores based on diarylated thieno[3,4-b]thiophenes efficiently synthesized by direct C-H arylation reaction. TbT-Fluors showed full-color-tunable emissions with large Stokes shifts. Intriguingly,the fluorescence quantum yields of TbT-Fluors are barely sensitive to solvent polarities, approaching 100%. Based on photophysical and theoretical investigations, we found that the enhanced oscillator strength of the S_1-S_0 transition and increased T2-S1 energy difference can sufficiently compensate the negative effect from the decreased energy gap and increased reorganization energy in dimethyl sulfoxide(DMSO). Bioimaging applications revealed that some TbT-Fluors can penetrate the cell membrane and are superior for imaging in terms of high photochemical stability and low cytotoxicity. Furthermore, TbT-PhF exhibits specific colocalization with mitochondria in living cells.展开更多
All-polymer solar cells(all-PSCs)comprising polymer donors and polymer acceptors have attracted considerable attention due to their superior photo-thermal stability and mechanical stretchability[1-3].However,the early...All-polymer solar cells(all-PSCs)comprising polymer donors and polymer acceptors have attracted considerable attention due to their superior photo-thermal stability and mechanical stretchability[1-3].However,the early polymer acceptors exhibit weak absorption coefficients in the longer wavelength region(600-900 nm),limiting the photovoltaic performances of all-PSCs[4-8].In order to address this issue,polymerization of the state-of-the-art A-D-A smallmolecule acceptors(SMAs)viaπ-linkers was proposed to develop new polymer acceptors[9].The polymerized SMAs(PSMAs)can not only inherit the strong near-infrared absorption from the corresponding SMAs,but also have tunable electronic energy levels,thus greatly improving the photovoltaic performances of all-PSCs[10-20].Particularly,the power conversion efficiencies(PCEs)have even surpassed 19%for the all-PSCs based on the Y-series PSMAs and suitable polymer donors[21-24].展开更多
Dimerized small-molecule acceptors (DSMAs)have attracted increasing attention in organic solar cells(OSCs) due to the advantages of long-term morphology stabilityand exceptional repeatability. However, the power conve...Dimerized small-molecule acceptors (DSMAs)have attracted increasing attention in organic solar cells(OSCs) due to the advantages of long-term morphology stabilityand exceptional repeatability. However, the power conversionefficiencies of the DSMA-based OSCs are highlydependent on the dimerization modes and the underlyingstructure-performance relationship remains unclear. Here, wehave revealed the role of end-group (EG) engineering of the AD-A small-molecule acceptors (SMAs) in tuning the electronic,optical, and electron transport properties of vinyl-bridgedDSMAs by multiscale theoretical calculations. The resultspoint out that the EG engineering can effectively modulate thelowest unoccupied molecular orbital (LUMO) electron densityat the linkage atoms of the SMAs, leading to a broad range ofsuper-exchange (SE) couplings for intramolecular electrontransfer between two SMA units among the studied DSMAs.Consequently, the LUMO energy and distribution are greatlychanged, which further change the excited state energy andoscillator strength. In addition, the different EGs have importantinfluences on the intermolecular electronic couplingsand connectivity. Notably, compared to the previously reportedDSMA of BB-V, the new-designed NB-V demonstratessimultaneous improvements in light absorption and electronmobility due to well-balanced intramolecular and intermolecularelectronic couplings. This work provides helpfulinsights into the development of DSMAs for high-efficiencyOSCs.展开更多
The effect of chalcogen heteroatom variation on donor materials has been systematically investigated. However, this effect on acceptors has rarely been explored. Herein, nonfullerene acceptors BFPSP and BFPTP were rep...The effect of chalcogen heteroatom variation on donor materials has been systematically investigated. However, this effect on acceptors has rarely been explored. Herein, nonfullerene acceptors BFPSP and BFPTP were reported by simply changing the chalcogen atoms from S to Te. The differences between BFPSP and BFPTP in light absorption, energy levels, excited-state lifetimes, energy loss, charge mobilities, morphology, and photovoltaic properties were systematically investigated to understand the heteroatom effects. More importantly, the electroluminescence spectra, external quantum efficiency of photovoltaics and TDDFTcalculations revealed that the triplet excited state(T1) in energy of BFPTP equals to the charge transfer(CT) state in PBDBT:BFPTP, which allows T1 excitons, generated by intersystem crossing, to split into free charges to contribute to the efficiency.This contribution provides a strategy for tuning the photophysical properties of nonfullerene acceptors and designing high performance triplet materials for OSCs.展开更多
Increasing multidrug-resistant （MDR） superbugs emerge worldwide causing a public health crisis. Consequently, it is urgent to find new antibiotics with efficient broad-spectrum antimicrobial activity. By virtue of v...Increasing multidrug-resistant （MDR） superbugs emerge worldwide causing a public health crisis. Consequently, it is urgent to find new antibiotics with efficient broad-spectrum antimicrobial activity. By virtue of versatility in molecular design, a new peptide-like cell membrane-broken molecule, oligo-（7,7＇-bifluoren-benzo[c][1,2,5]thiadiazole） （OFBT） possessing a conjugated backbone and eight pendant guanidyl moieties was designed and synthesized. OFBT exhibits favorable broad-spectrum of antirnicrobial activity to pathogens including Gram-negative and Gram-positive bacteria, and fungi with the minimum inhibitory concentration （MIC） below 3.0 μM. Moreover, OFBT exhibits high selectivity for pathogens over human cells to make it a promising broad spectrum antimicrobial agent.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
An electron collection layer(ECL)between a photoactive overlay and an electrode plays a crucial role in optimizing the light field and charge extraction in bulk-heterojunction(BHJ)polymer solar cells(PSCs).However,the...An electron collection layer(ECL)between a photoactive overlay and an electrode plays a crucial role in optimizing the light field and charge extraction in bulk-heterojunction(BHJ)polymer solar cells(PSCs).However,the typical thickness of the photoactive layer is thinner than its optical path lengths,limiting further improvement of light absorption and device performance.展开更多
State-of-the-art organic solar cells(OSCs)often require the use of high-boiling point additive or post-treatment such as temperature annealing and solvent vapor annealing to achieve the best efficiency.However,additiv...State-of-the-art organic solar cells(OSCs)often require the use of high-boiling point additive or post-treatment such as temperature annealing and solvent vapor annealing to achieve the best efficiency.However,additives are not desirable in largescale industrial printing process,while post-treatment also increases the production cost.In this article,we report highly efficient ternary OSCs based on PM6:BTP-Cl Br1:BTP-2O-4Cl-C12(weight ratio=1:1:0.2),with 16.68%power conversion efficiency(PCE)for as-cast device,relatively close to its annealed counterpart(17.19%).Apart from obvious energy tuning effect and complementary absorption spectra,the improved PCE of ternary device is mainly attributed to improved morphological properties including the more favorable materials miscibility,crystallinity,domain size and vertical phase separation,which endorse suppressed recombination.The result of this work provides understanding and guidance for high-performance as-cast OSCs through the ternary strategy.展开更多
Molecular doping is essential to improve the electrical conductivity of organic semiconductors for high-performance organic electronic devices. However, the doping efficiency is influenced by several factors, such as ...Molecular doping is essential to improve the electrical conductivity of organic semiconductors for high-performance organic electronic devices. However, the doping efficiency is influenced by several factors, such as the energy levels, energetic fluctuations, dielectric properties, and molecular packing structures of the doped films, and the underlying mechanisms for highefficiency doping are still unclear. Here, through multi-level theoretical simulations on a series of fullerene derivatives, we identify that the energetic fluctuations can play a decisive role in activating charge separation for molecular doping. In particular,the doping efficiency appears to be exponentially increased with the fluctuation of charge polarization energies. Therefore,although the charge mobility is somewhat decreased, the experimental electrical conductivity is improved with the increased energetic fluctuation. Moreover, it has been found that polarization energy fluctuation can be effectively enhanced by simply introducing side chains with greater flexibility into organic semiconductors. This article paves the way towards high-efficiency molecular doping of organic semiconductors.展开更多
Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics.The widely adopted strategies to enhance charge transport,such as restraining intermolecular vibratio...Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics.The widely adopted strategies to enhance charge transport,such as restraining intermolecular vibration,are mostly limited to organic molecules,which are nearly inoperative in 2D inor-ganic molecular crystals currently.In this contribution,charge transport in 2D inorganic molecular crystals is improved by integrating charge-delocalized Se8 rings as building blocks,where the delocalized electrons on Se8 rings lift the intermolecular orbitals overlap,offering efficient charge transfer channels.Besides,α-Se flakes composed of charge-delocalized Se8 rings possess small exciton binding energy.Benefitting from these,α-Se flake exhibits excellent photodetection performance with an ultrafast response rate(�5μs)and a high detectivity of 1.08�1011 Jones.These findings contribute to a deeper under-standing of the charge transport of 2D inorganic molecular crystals composed of electron-delocalized inorganic molecules and pave the way for their poten-tial application in optoelectronics.展开更多
基金financially supported by the National Natural Science Foundation of China (NSFC) (Nos. 21674007 and 21734001)the financial support from National Research Foundation (NRF) of Korea (2012M3A6A7055540 and 2015M1A2A2057506)
文摘Research on asymmetric A–D–A structured non-fullerene acceptors has lagged far behind the development of symmetric counterpart.In this contribution,by simply replacing one sulfur atom in indacenodithiophene unit with a selenium atom,an asymmetric building block Se PT and a corresponding asymmetric non-fullerene acceptor Se PT-IN have been developed.Asymmetric Se PT-IN achieved a high efficiency of 10.20% in organic solar cells when blended with PBT1-C,much higher than that of symmetric TPT-IN counterpart(8.91%).Our results demonstrated an effective heteroatom substitution strategy to develop asymmetric A–D–A structured non-fullerene acceptors.
基金financially supported by the National Natural Science Foundation of China (No. 51773208)the Ministry of Science and Technology of China (No. 2014CB643506)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB12020200).
文摘Organic solar cells based on acceptor-p-acceptor(A-π-A) electron acceptors have attracted intensive attention due to their increasing and record power conversion efficiencies. To date, almost all of the reported A-π-A electron acceptors are based on aromatic p structures. Here, we have investigated the impact of anti-aromatization of the p-bridges on the optoelectronic properties of A-π-A electron acceptors by(time-dependent) density functional theory. Our calculations show that besides the frontier molecular orbitals corresponding to the aromatic p-bridge based acceptors("aromatic" acceptors),additional and unique occupied and unoccupied frontier orbitals are found for the acceptors based on the anti-aromatic p-bridges("anti-aromatic" acceptors). Moreover, by tuning isomeric structures of the p-bridges(e.g., fusion orientations or linking positions of thiophene moieties), the optical excitation energies for the transition between the additional occupied and unoccupied levels turn to be close to or substantially lower with respect to those for the transition between the "aromatic" frontier orbitals. The optical absorption of the "anti-aromatic" acceptors is thus either stronger or broader than the "aromatic"acceptors. Finally, the reorganization energies for electron transport are tunable and dependent on the p-bridge structures. These results indicate a great potential of "anti-aromatic" electron acceptors in organic photovoltaics.
基金supported by the National Natural Science Foundation of China(Grant no.51773208,51803216)the Ministry of Science and Technology of China(Grant no.2014CB643506)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDB12020200)
文摘Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chains on the molecular packing and electron transport properties of a series of bay-linked dimeric perylenediimide(PDI) derivatives by atomistic molecular dynamics simulations in combination with charge transfer rate theory and kinetic Monte Carlo simulations. The results show that despite of different branching positions of the alkyl chains,π–π stacking is effectively inhibited for all the dimeric PDI derivatives. As the branching position moves away from the PDI backbone, the appearance of the alkyl atoms around the PDI backbone will first decrease and then increase. Correspondingly, the short contacts between the PDI moieties are first enhanced and then reduced. In particular, when the branching position is at the third carbon atom, the intermolecular connectivity becomes the most effective and the electron mobility is significantly increased by 2 times.
基金support from the Ministry of Science and Technology of China(No.2017YFA0204502)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB12020200)。
文摘Electronic polarization has an important impact on the site energies of charge carriers that play a key role in determining the charge transport in organic semiconductors.Dipolar molecules have strong intermolecular interactions and widespread applications in organic optoelectronics.Howeve r,compared with nonpolar organic semiconductors,electronic polarization for dipolar systems has been rarely studied.Here,taking 1,2,3,4-tetrafluoro-6,7-dimethylnaphthalene as representative,we have calculated the electronic polarization energies of dipolar organic molecular crystals by means of a polarizable forcefield method.Surprisingly,our results point to that the polarization energies for this dipolar system are similar to those of nonpolar systems.In addition,theπ-πstack contributes only about 30%~40%to the total polarization energy,thus the polarization effects along the three dimensions should be treated equally even for the one-dimensional stacking crystals.
基金supported by the National Basic Research Program of China(2014CB643502)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12010200)the National Natural Science Foundation of China(91333113,21572234)
文摘Organic fluorophores are indispensible in chemical/biological imaging. The conjugated fluorescent molecules simultaneously possessing highly tunable emission, high quantum yield in solvents of different polarities, and large Stokes shift are quite rare. Herein, we report a new category of fluorophores based on diarylated thieno[3,4-b]thiophenes efficiently synthesized by direct C-H arylation reaction. TbT-Fluors showed full-color-tunable emissions with large Stokes shifts. Intriguingly,the fluorescence quantum yields of TbT-Fluors are barely sensitive to solvent polarities, approaching 100%. Based on photophysical and theoretical investigations, we found that the enhanced oscillator strength of the S_1-S_0 transition and increased T2-S1 energy difference can sufficiently compensate the negative effect from the decreased energy gap and increased reorganization energy in dimethyl sulfoxide(DMSO). Bioimaging applications revealed that some TbT-Fluors can penetrate the cell membrane and are superior for imaging in terms of high photochemical stability and low cytotoxicity. Furthermore, TbT-PhF exhibits specific colocalization with mitochondria in living cells.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0520102)the National Key R&D Program of China(2024YFA1209600)+1 种基金the National Natural Science Foundation of China(22173108)the Youth Innovation Promotion Association CAS(2023037).
文摘All-polymer solar cells(all-PSCs)comprising polymer donors and polymer acceptors have attracted considerable attention due to their superior photo-thermal stability and mechanical stretchability[1-3].However,the early polymer acceptors exhibit weak absorption coefficients in the longer wavelength region(600-900 nm),limiting the photovoltaic performances of all-PSCs[4-8].In order to address this issue,polymerization of the state-of-the-art A-D-A smallmolecule acceptors(SMAs)viaπ-linkers was proposed to develop new polymer acceptors[9].The polymerized SMAs(PSMAs)can not only inherit the strong near-infrared absorption from the corresponding SMAs,but also have tunable electronic energy levels,thus greatly improving the photovoltaic performances of all-PSCs[10-20].Particularly,the power conversion efficiencies(PCEs)have even surpassed 19%for the all-PSCs based on the Y-series PSMAs and suitable polymer donors[21-24].
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB0520102)the National Natural Science Foundation of China (22173108)the Youth Innovation Promotion Association CAS (2023037)。
文摘Dimerized small-molecule acceptors (DSMAs)have attracted increasing attention in organic solar cells(OSCs) due to the advantages of long-term morphology stabilityand exceptional repeatability. However, the power conversionefficiencies of the DSMA-based OSCs are highlydependent on the dimerization modes and the underlyingstructure-performance relationship remains unclear. Here, wehave revealed the role of end-group (EG) engineering of the AD-A small-molecule acceptors (SMAs) in tuning the electronic,optical, and electron transport properties of vinyl-bridgedDSMAs by multiscale theoretical calculations. The resultspoint out that the EG engineering can effectively modulate thelowest unoccupied molecular orbital (LUMO) electron densityat the linkage atoms of the SMAs, leading to a broad range ofsuper-exchange (SE) couplings for intramolecular electrontransfer between two SMA units among the studied DSMAs.Consequently, the LUMO energy and distribution are greatlychanged, which further change the excited state energy andoscillator strength. In addition, the different EGs have importantinfluences on the intermolecular electronic couplingsand connectivity. Notably, compared to the previously reportedDSMA of BB-V, the new-designed NB-V demonstratessimultaneous improvements in light absorption and electronmobility due to well-balanced intramolecular and intermolecularelectronic couplings. This work provides helpfulinsights into the development of DSMAs for high-efficiencyOSCs.
基金supported by the National Natural Science Foundation of China(21774130,21673054)the National Key Research and Development Program of China(2018FYA 0305800)+6 种基金the Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-JSC046)Key Research Program of the Chinese Academy of Sciences(XDPB08-2)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB28000000,XDB12020200)External Cooperation Programs of Chinese Academy of Sciences(211211KYSB20170014)Innovation Program of Aerospace Science and Technology,China Aerospace Science and Technology CorporationOne Hundred Talents Program of Chinese Academy of Sciences,and University of Chinese Academy of Sciences,the Ministry of Science and Technology(2017YFA0205004,2016YFA0200700)Beijing Natural Research Foundation(4182076)
文摘The effect of chalcogen heteroatom variation on donor materials has been systematically investigated. However, this effect on acceptors has rarely been explored. Herein, nonfullerene acceptors BFPSP and BFPTP were reported by simply changing the chalcogen atoms from S to Te. The differences between BFPSP and BFPTP in light absorption, energy levels, excited-state lifetimes, energy loss, charge mobilities, morphology, and photovoltaic properties were systematically investigated to understand the heteroatom effects. More importantly, the electroluminescence spectra, external quantum efficiency of photovoltaics and TDDFTcalculations revealed that the triplet excited state(T1) in energy of BFPTP equals to the charge transfer(CT) state in PBDBT:BFPTP, which allows T1 excitons, generated by intersystem crossing, to split into free charges to contribute to the efficiency.This contribution provides a strategy for tuning the photophysical properties of nonfullerene acceptors and designing high performance triplet materials for OSCs.
基金supported by the National Natural Science Foundation of China (21533012, 21473220)Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09030306)
文摘Increasing multidrug-resistant （MDR） superbugs emerge worldwide causing a public health crisis. Consequently, it is urgent to find new antibiotics with efficient broad-spectrum antimicrobial activity. By virtue of versatility in molecular design, a new peptide-like cell membrane-broken molecule, oligo-（7,7＇-bifluoren-benzo[c][1,2,5]thiadiazole） （OFBT） possessing a conjugated backbone and eight pendant guanidyl moieties was designed and synthesized. OFBT exhibits favorable broad-spectrum of antirnicrobial activity to pathogens including Gram-negative and Gram-positive bacteria, and fungi with the minimum inhibitory concentration （MIC） below 3.0 μM. Moreover, OFBT exhibits high selectivity for pathogens over human cells to make it a promising broad spectrum antimicrobial agent.
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supported by the National Natural Science Foundation of China(grant nos.51873007,51961165102,and 21835006)the Fundamental Research Funds for the Central Universities in China(grant nos.2019MS025,2018MS032,and 2019QN057).
文摘An electron collection layer(ECL)between a photoactive overlay and an electrode plays a crucial role in optimizing the light field and charge extraction in bulk-heterojunction(BHJ)polymer solar cells(PSCs).However,the typical thickness of the photoactive layer is thinner than its optical path lengths,limiting further improvement of light absorption and device performance.
基金support by the National Key Research and Development Program of China(2019YFA0705900)funded by Minister of Science and Technologythe Basic and Applied Basic Research Major Program of Guangdong Province(2019B030302007)+9 种基金the Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002)the Shen Zhen Technology and Innovation Commission(JCYJ20170413173814007,JCYJ20170818113905024)the Hong Kong Research Grants Council(Research Impact Fund R6021-18,collaborative research fund C6023-19G,project numbers,16309218,16310019,16303917)Hong Kong Innovation and Technology Commission(for the support through projects ITCCNERC14SC01 and ITS/471/18)the National Natural Science Foundation of China(NSFC,91433202)the support by the National Natural Science Foundation of China(NSFC,51773142,51973146)the Jiangsu Provincial Natural Science Foundation(BK20190099)the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe support by Hong Kong PhD Fellowship Scheme(PF17-03929)the support from Design and Manufacturing Services Facility(DMSF)and Materials Characterization and Preparation Facility(MCPF)of Hong Kong University of Science&Technology(HKUST)on characterizations。
文摘State-of-the-art organic solar cells(OSCs)often require the use of high-boiling point additive or post-treatment such as temperature annealing and solvent vapor annealing to achieve the best efficiency.However,additives are not desirable in largescale industrial printing process,while post-treatment also increases the production cost.In this article,we report highly efficient ternary OSCs based on PM6:BTP-Cl Br1:BTP-2O-4Cl-C12(weight ratio=1:1:0.2),with 16.68%power conversion efficiency(PCE)for as-cast device,relatively close to its annealed counterpart(17.19%).Apart from obvious energy tuning effect and complementary absorption spectra,the improved PCE of ternary device is mainly attributed to improved morphological properties including the more favorable materials miscibility,crystallinity,domain size and vertical phase separation,which endorse suppressed recombination.The result of this work provides understanding and guidance for high-performance as-cast OSCs through the ternary strategy.
基金supported by the Beijing Natural Science Foundation (2244083)the National Natural Science Foundation of China (22173108)+1 种基金the Ministry of Science and Technology of China (2018YFA0703200)the Youth Innovation Promotion Association CAS (2023037)。
文摘Molecular doping is essential to improve the electrical conductivity of organic semiconductors for high-performance organic electronic devices. However, the doping efficiency is influenced by several factors, such as the energy levels, energetic fluctuations, dielectric properties, and molecular packing structures of the doped films, and the underlying mechanisms for highefficiency doping are still unclear. Here, through multi-level theoretical simulations on a series of fullerene derivatives, we identify that the energetic fluctuations can play a decisive role in activating charge separation for molecular doping. In particular,the doping efficiency appears to be exponentially increased with the fluctuation of charge polarization energies. Therefore,although the charge mobility is somewhat decreased, the experimental electrical conductivity is improved with the increased energetic fluctuation. Moreover, it has been found that polarization energy fluctuation can be effectively enhanced by simply introducing side chains with greater flexibility into organic semiconductors. This article paves the way towards high-efficiency molecular doping of organic semiconductors.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A2069,21825103)the China Postdoctoral Science Foundation(Grant No.2021M691108).
文摘Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics.The widely adopted strategies to enhance charge transport,such as restraining intermolecular vibration,are mostly limited to organic molecules,which are nearly inoperative in 2D inor-ganic molecular crystals currently.In this contribution,charge transport in 2D inorganic molecular crystals is improved by integrating charge-delocalized Se8 rings as building blocks,where the delocalized electrons on Se8 rings lift the intermolecular orbitals overlap,offering efficient charge transfer channels.Besides,α-Se flakes composed of charge-delocalized Se8 rings possess small exciton binding energy.Benefitting from these,α-Se flake exhibits excellent photodetection performance with an ultrafast response rate(�5μs)and a high detectivity of 1.08�1011 Jones.These findings contribute to a deeper under-standing of the charge transport of 2D inorganic molecular crystals composed of electron-delocalized inorganic molecules and pave the way for their poten-tial application in optoelectronics.
