The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impac...The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.展开更多
A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamin...A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs.展开更多
Nonfused ring electron acceptors(NFREAs)have attracted much attention due to their concise synthetic routes and low cost.However,developing high-performance NFREAs with simple structure remains a great challenge.In th...Nonfused ring electron acceptors(NFREAs)have attracted much attention due to their concise synthetic routes and low cost.However,developing high-performance NFREAs with simple structure remains a great challenge.In this work,a simple building block(POBT)with noncovalently conformational locks(No CLs)was designed and synthesized.Single-crystal X-ray study indicated the presence of S…O NOCLs in POBT,thus enabling it to possess a coplanar conformation comparable to that of fused-ring CPT.Two novel NFREAs based on CPT and POBT were developed,namely TT-CPT and TT-POBT,respectively.Besides,TT-POBT possessed a smaller Stokes shift and a reduced reorganization energy compared with TT-CPT,indicating the introduction of S…O No CLs can enhance the molecular rigidity even if simplifying the molecular structure.As a result,the TT-POBT-based PSC device afforded an impressive power conversion efficiency of 11.15%,much higher than that of TT-CPT counterpart(7.03%),mainly resulting from the tighterπ-πstacking,improved and balanced charge transport,and more favorable film morphology.This work demonstrates the potential of the simple building block POBT with No CLs towards constructing low-cost and highperformance NFREAs.展开更多
Non-fullerene polymer solar cells(NF-PSCs) have gained wide attention recently. Molecular design of non-fullerene electron acceptors effectively promotes the photovoltaic performance of NF-PSCs. However,molecular elec...Non-fullerene polymer solar cells(NF-PSCs) have gained wide attention recently. Molecular design of non-fullerene electron acceptors effectively promotes the photovoltaic performance of NF-PSCs. However,molecular electron acceptors with 2-dimensional(2 D) configuration and conjugation are seldom reported.Herein, we designed and synthesized a series of novel 2 D electron acceptors for efficient NF-PSCs. With rational optimization on the conjugated moieties in both vertical and horizontal direction, these 2 D electron acceptors showed appealing properties, such as good planarity, full-spectrum absorption, high absorption extinction coefficient, and proper blend morphology with donor polymer. A high PCE of 9.76%was achieved for photovoltaic devices with PBDB-T as the donor and these 2 D electron acceptors. It was also found the charge transfer between the conjugated moieties in two directions of these 2 D molecules contributes to the utilization of absorbed photos, resulting in an exceptional EQE of 87% at 730 nm. This work presents rational design guidelines of 2 D electron acceptors, which showed great promise to achieve high-performance non-fullerene polymer solar cells.展开更多
Fullerenes and their derivatives are important types of electron acceptor materials and play a vital role in organic solar cell devices. However, the fullerene acceptor material has some difficulties to overcome the i...Fullerenes and their derivatives are important types of electron acceptor materials and play a vital role in organic solar cell devices. However, the fullerene acceptor material has some difficulties to overcome the intrinsic shortcomings, such as weak absorption in the visible range, difficulty in modification and high cost, which limit the performance of the device and the large-scale application of this type of acceptors. In recent years, non-fullerene electron acceptor material has attracted the attention of scientists due to the advantages of adjustable energy level, wide absorption, simple synthesis, low processing cost and good solubility. Researchers can use the rich chemical means to design and synthesize organic small molecules and their oligomers with specific aggregation morphology and excellent optoelectronic prop- erties. Great advances in the field of synthesis, device engineering, and device physics of non-fullerene acceptors have been achieved in the last few years. At present, non-fullerene small molecules based photovoltaic devices achieve the highest efficiency more than 13% and the efficiency gap between fullerenetype and non-fullerene-type photovoltaic devices is gradually narrowing. In this review, we explore recent progress of non-fullerene small molecule electron acceptors that have been developed and led to highefficiency photovoltaic devices and put forward the prospect of development in the future.展开更多
Benefitting from the development of non-fullerene acceptors(NFAs),remarkable advances have been achieved with the power conversion efficiency(PCE)exceeding 19%over the last few years.However,the major achievement come...Benefitting from the development of non-fullerene acceptors(NFAs),remarkable advances have been achieved with the power conversion efficiency(PCE)exceeding 19%over the last few years.However,the major achievement comes from fused ring electron acceptors(FREAs)with complex structures,leading to high cost.Hence,it is urgent to design new materials to resolve the cost issues concerning basic commercial requirements of organic solar cells.Recently,great progress has been made in fully non-fused ring electron acceptors(NFREAs)with only single-aromatic ring in the electron-donating core,which might achieve a fine balance between the efficiency and cost,thus accelerating the commercial application of organic solar cells.Therefore,this article summarizes the recent advances of fully NFREAs with efficiency over 10%,which may provide a guidance for developing the cost-effective solar cells.展开更多
Non-fused ring electron acceptors(NFREAs)have a broad application prospect in the commercialization of organic solar cells(OSCs)due to the advantages of simple synthesis and low cost.The selection of intermediate bloc...Non-fused ring electron acceptors(NFREAs)have a broad application prospect in the commercialization of organic solar cells(OSCs)due to the advantages of simple synthesis and low cost.The selection of intermediate block cores of non-fused frameworks and the establishment of the relationship between molecular structure and device performance are crucial for the realization of high-performance OSCs.Herein,two A-D-A’-D-A type NFREAs namely CBTBO-4F and CBTBO-4Cl,constructed with a novel electron-deficient block unit N-(2-butyloctyl)-carbazole[3,4-c:5,6-c]bis[1,2,5]thiadiazole(CBT)and bridging unit 4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene(DTC)coupling with different terminals(IC-2F/2Cl),were designed and synthesized.The two NFREAs feature broad and strong photoresponse from 500 nm to 900 nm due to the strong intramolecular charge transfer characteristics.Compared with CBTBO-4F,CBTBO-4Cl shows better molecular planarity,stronger crystallinity,more ordered molecular stacking,larger van der Waals surface,lower energy level and better active layer morphology,contributing to much better charge separation and transport behaviors in its based devices.As a result,the CBTBO-4Cl based device obtains a higher power conversion efficiency of 10.18%with an open-circuit voltage of 0.80 V and a short-circuit current density of 21.20 mA/cm^(2).These results not only demonstrate the great potential of CBT,a new building block of the benzothiazole family,in the construction of high-performance organic conjugated semiconductors,but also suggest that the terminal chlorination is an effective strategy to improve device performance.展开更多
Sulfate and nitrate reducing bacteria are important culprits for microbiologically influenced corrosion(MIC)using sulfate and nitrate as electron acceptors,respectively.Sulfate and nitrate hold different standard elec...Sulfate and nitrate reducing bacteria are important culprits for microbiologically influenced corrosion(MIC)using sulfate and nitrate as electron acceptors,respectively.Sulfate and nitrate hold different standard electrode potentials,which may lead to differences in corrosion,but their effects on corrosion by the same bacteria have not been reported.The corrosion of Q235 steel affected by Pseudodesulfovibrio cashew(P.cashew)in the sulfate and nitrate media under carbon starvation was studied.It was found that sulfate and nitrate did not lead to differences in corrosion under abiotic conditions.However,P.cashew promoted corrosion in both cases,and the consumption of H_(2)was the main mechanism for MIC.In addition,corrosion was more severe in the sulfate media.The higher corrosivity of P.cashew with sulfate as the electron acceptor is closely related to the higher number of sessile cells in the biofilm,higher bacterial motility,more hydrogen production pathways,and the increased gene expression of enzymes related to energy synthesis.展开更多
The effects of two different external carbon sources （acetate and ethanol） and electron acceptors （dissolved oxygen, nitrate, and nitrite） were investigated under aerobic and anoxic conditions with non-acclimated ...The effects of two different external carbon sources （acetate and ethanol） and electron acceptors （dissolved oxygen, nitrate, and nitrite） were investigated under aerobic and anoxic conditions with non-acclimated process bi- omass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/（g MLVSS.h） （MLVSS： mixed liquor volatile suspended solids）, respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO2-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher deni- trification rates were obtained with acetate （1.4 and 0.8 mg N/（g MLVSS.h）） compared to ethanol （1.1 and 0.7 mg N/ （g MLVSS.h）） for both anoxic electron acceptors （nitrate and nitrite）.展开更多
The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was ...The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was studied at ambient conditions.In the absence of an electron acceptor,only HO^·radicals were generated by irradiated UV light and TiO2.However,in the presence of the two electron acceptors,both HO^· radical and ^1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor.The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2.The type of generated value-added compounds depended on the concentration of the generated ROS.展开更多
Developing narrow-bandgap organic semiconductors is important to facilitate the advancement of organic photovoltaics(OPVs). Herein, two near-infrared non-fused ring acceptors(NIR NFRAs), PTBFTT-F and PTBFTT-Cl have be...Developing narrow-bandgap organic semiconductors is important to facilitate the advancement of organic photovoltaics(OPVs). Herein, two near-infrared non-fused ring acceptors(NIR NFRAs), PTBFTT-F and PTBFTT-Cl have been developed with A-π_A-π_D-D-π_D-π_A-A non-fused structures. It is revealed that the introduction of electron deficient π-bridge(π_A) and multiple intramolecular noncovalent interactions effectively retained the structural planarity and intramolecular charge transfer of NFRAs, extending strong NIR photon absorption up to 950 nm. Further, the chlorinated acceptor, with the enlarged π-surface compared to the fluorinated counterpart, promoted not only molecular stacking in solid, but also the desirable photochemical stability in ambient, which are helpful to thereby improve the exciton and charge dynamics for the corresponding OPVs. Overall, this work provides valuable insights into the design of NIR organic semiconductors.展开更多
In this work, star-shaped perylene bisimide(PBI) derivatives with spiro-aromatic cores linked with ethynyl units were developed as electron acceptors for non-fullerene organic solar cells. The ethynyl linkers were fou...In this work, star-shaped perylene bisimide(PBI) derivatives with spiro-aromatic cores linked with ethynyl units were developed as electron acceptors for non-fullerene organic solar cells. The ethynyl linkers were found to enhance the planarity of the conjugated backbone, resulting in high electron mobilities and near-infrared absorption. The ethynyl-linked PBI acceptors showed high power conversion efficiencies(PCEs) up to 4.27% due to the high short-circuit current density(Jsc) of 8.52 mA/cm^2 and fill factor(FF) of 0.59, while the PBI acceptor without ethynyl units provided a low PCE of 3.57% in nonfullerene solar cells. The results demonstrate that ethynyl units can be applied into designing new PBI electron acceptors with improved charge transport properties and photovoltaic performance.展开更多
Characteristics of phosphorus removal bacteria were investigated by using three different types of electron acceptors, as well as the positive role of nitrite in phosphorus removal process. An （AO）^2 SBR （anaerobic...Characteristics of phosphorus removal bacteria were investigated by using three different types of electron acceptors, as well as the positive role of nitrite in phosphorus removal process. An （AO）^2 SBR （anaerobic-aerobic-anoxic-aerobic sequencing batch reactor） was thereby employed to enrich denitrifying phosphorus removal bacteria for simultaneously removing phosphorus and nitrogen via auoxic phosphorus uptake, Ammonium oxidation was controlled at the first phase of the nitrification process. Nitrite-inhibition batch tests illustrated that nitrite was not an inhibitor to phosphorus uptake process, but served as an alternative electron acceptor to nitrate and oxygen if the concentration was under the inhibition level of 40mg NO2 - N·L^- 1. It implied that in addition to the two well-accepted groups of phosphorus removal bacterium （ one can only utilize oxygen as electron acceptor, P1, while the other can use both oxygen and nitrate as electron acceptor, P2 ）, a new group of phosphorus removal bacterium P3, which could use oxygen, nitrate and nitrite as electron acceptor to take up phosphorus were identified in the test system. To understand （AO）^2 SBR sludge better, the relative population of the different bacteria in this system, plus another A/O SBR sludge （ seed sludge） were respectively estimated by the phosphorus uptake batch tests with either oxygen or nitrate or nitrite as electron acceptor. The results demonstrated that phosphorus removal capability of （AO）^2 SBR sludge had a little degradation after A/O sludge was cultivated in the （AO）^2 mode over a long period of time. However, deuitrifying phosphorus removal bacteria （ P2 and P3 ） was significantly enriched showed by the relative population of the three types of bacteria, which implied that energy for aeration and COD consumption could be reduced in theory.展开更多
Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a d...Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a deficiency in understanding the structure-property relationship.Herein,we investigated two low-cost terthiophene-based electron acceptors,namely,3TC8 and 3TEH,with 3,4-bis(octan-3-yloxy)thiophene,differing only in the alkylated thiophene-bridges.Both acceptors exhibit low optical gaps(∼1.43 eV)and possess deep highest occupied molecular orbital(HOMO)levels(∼−5.8 eV).Notably,the single-crystal structure of 3TEH demonstrates highly planar conjugated backbone and strongπ-πstacking between intermolecular terminal groups,attributed to the presence of the bulky alkylated noncovalently conformational locks.Upon utilizing both acceptors to fabricate OSCs,the 3TC8-based device exhibited a power conversion efficiency(PCE)of 11.1%,while the 3TEH-based OSC demonstrated an excellent PCE of 14.4%.This PCE is the highest among OSCs based on terthiophene-containing electron acceptors.These results offer a new strategy for designing low-cost electron acceptors for highly efficient OSCs.展开更多
We synthesize and compare four near-infrared absorbing fused-ring electron acceptors named as nTTIC(n=2,3,4,and 5),based on different number of thieno[3,2-b]thiophene(TT)unit as the electron-donating core.With increas...We synthesize and compare four near-infrared absorbing fused-ring electron acceptors named as nTTIC(n=2,3,4,and 5),based on different number of thieno[3,2-b]thiophene(TT)unit as the electron-donating core.With increasing the TT unit,absorption spectrum of the TTIC series red shifts,and the highest occupied molecular orbital(HOMO)upshifts notably.It is worth noting that 4TTIC and 5TTIC exhibit absorption edges approaching 1100 nm,which is the photoresponse limit of solar cells based on crystal silicon.When the TTIC series acceptors are blended with polymer donor PM6,the binary-blend organic solar cells based on 3TTIC show the best power conversion efficiency(PCE)of 13.1%.In contrast,2TTIC-based devices exhibit relatively lower PCE of 8.32%,mainly caused by the larger energy loss and blue-shifted absorption.Due to insufficient driving force of charge separation caused by very high HOMO,4TTIC and 5TTIC show poor PCEs lower than 3%.展开更多
Metal-organic framework(MOF)photocatalysts have shown promising application in photocatalytic Cr(VI)reduction,but their activities are still restrained by severe charge recombination.To overcome this limitation,herein...Metal-organic framework(MOF)photocatalysts have shown promising application in photocatalytic Cr(VI)reduction,but their activities are still restrained by severe charge recombination.To overcome this limitation,herein we propose that the incorporation of cocatalysts as electron acceptors inside MOF pores can provide a better chance to separate the photogenerated electrons,compared with traditional methods to cover cocatalysts on the MOF surface.Following this strategy,we demonstrate a facile method to in situ generate carbon quantum dots(CQDs)as cocatalysts inside a typical MOF photocatalyst(MIL-53(Fe)).The CQDs can serve as efficient localized electron acceptors for separating the photogenerated carriers from the inner metal-oxo clusters among the MOFs,and thus their photocatalytic activities can be greatly improved.Besides acting as electron acceptors,we also reveal that the CQDs can work as photosensitizers for the MOF particles under long-wavelength light irradiation,playing a second role to enhance their activities.The MIL-53(Fe)/CQD composites have been well characterized and their photocatalytic mechanism has been proposed.展开更多
Bulky aromatic side groups are an effective strategy for the design of highly efficient fully nonfused electron acceptors(FNEAs)by creating spatial confinement to achieve backbone planarity.However,theπ-πinteraction...Bulky aromatic side groups are an effective strategy for the design of highly efficient fully nonfused electron acceptors(FNEAs)by creating spatial confinement to achieve backbone planarity.However,theπ-πinteractions between the steric aromatic groups can induce single bond rotation and form a twisting molecular configuration.Hence,it’s crucial to improve the positive planarization effect and inhibit the unfavorableπ-πinteracted competition from the steric groups.Herein,we designed and synthesized a series of tetrathiophene-based FNEAs,namely 4T-C2,4TC3,4T-C4,and 4T-C5,by precisely regulating the length of the alkyl side chain by systematically increasing it by one atom.Among the four FNEAs,only the n-propyl functionalized 4T-C3 accomplished a planar molecular backbone,which produced a highly interconnected three-dimensional charge transport network,confirmed by the single crystal characterization.Molecular dynamics simulations provided a deeper understanding of this structural variation,and results indicate that the length of alkyl-substituted side chains significantly influences intermolecular interaction,thereby achieving controllable regulation at molecular conformation.Finally,4T-C3 achieved outstanding power conversion efficiencies of 14.88%and 19.54%for binary and ternary organic solar cells,respectively.Overall,this work provides a systematic understanding and precise conformation regulation strategy for FNEAs design.展开更多
The development of high-performance nearinfrared(NIR)absorbing electron acceptors is a major challenge in achieving high short-circuit current density(JSC)to increase power conversion efficiency(PCE)of organic solar c...The development of high-performance nearinfrared(NIR)absorbing electron acceptors is a major challenge in achieving high short-circuit current density(JSC)to increase power conversion efficiency(PCE)of organic solar cells(OSCs).Herein,three new multi-heteroatomized Y-series acceptors(bi-asy-Y-Br,bi-asy-Y-FBr,and bi-asy-Y-FBrF)were developed by combining dual-asymmetric selenium-fused core and brominated end-groups with different numbers of fluorine substitutions.With gradually increasing fluorination,three acceptors exhibit red-shift absorption.Among them,biasy-Y-FBrF presents planar molecular geometry,the maximum average electrostatic potential,and the minimum molecular dipole moment,which are conducive to intramolecular packing and charge transport.Moreover,D18:bi-asy-Y-FBrF active layer presents higher crystallinity,more suitable phase separation,and reduced charge recombination compared to D18:bi-asy-Y-Br and D18:bi-asy-Y-FBr blends.Consequently,among theses binary OSCs,D18:bi-asy-Y-FBrF device achieves a higher PCE of 15.74% with an enhanced JSC of 26.28 mA cm^(-2),while D18:bi-asy-Y-Br device obtains a moderate PCE of 15.04% with the highest open-circuit voltage(VOC)of 0.926 V.Inspired by its high VOC and complementary absorption with NIR-absorbing BTP-eC9 as acceptor,bi-asy-Y-Br is introduced into binary D18:BTP-eC9 to construct ternary OSCs,achieving a further boosted PCE of 19.12%,which is among the top values for the reported green solvent processed OSCs.展开更多
The A–D–A′–D–A-type non-fused ring electron acceptors(NFREAs),consisting of electron-donating unit(D)as the bridge to link electron-accepting units(A and A′),have emerged as promising electron acceptors for orga...The A–D–A′–D–A-type non-fused ring electron acceptors(NFREAs),consisting of electron-donating unit(D)as the bridge to link electron-accepting units(A and A′),have emerged as promising electron acceptors for organic solar cells(OSCs)and organic photodetectors(OPDs).As the units are linked by the carbon–carbon single bonds,these electron acceptors generally possess feasible synthesis and tunable optoelectronic properties.Herein,the recent progress of A–D–A′–D–A-type NFREAs is reviewed,including molecular design,device performance,structure–property relationships,and their applications in OSCs and OPDs.Finally,we discuss the challenges and propose the perspectives for the further development of A–D–A′–D–A-type NFREAs.展开更多
Fullerene derivatives are classic electron acceptor materials for organic solar cells (Oscs) but possess some intrinsic drawbacks such as weak visiblelightabsorption,limitedoptoelectronic property tunability,dificult ...Fullerene derivatives are classic electron acceptor materials for organic solar cells (Oscs) but possess some intrinsic drawbacks such as weak visiblelightabsorption,limitedoptoelectronic property tunability,dificult purification and photochemical/morphological instability.Fullereneacceptors area bottleneck restricting further development of this field. Ourgroup pioneered the exploration of novel nonfulerene acceptors in China in 2006,andinitiated the research of two representative acceptor systems, rylene dimide polymer and fused-ring electron acceptor (FREA).FREA breaks the theoreticalefficiencylimit of fullerene-based OsCs (-13%) and promotes the whole field to an unprecedented prosperity with efficiency of 20%, heraldinga nonfullerene era for OsCs.In this review, we revisit 15-year nonfullerene exploration journey,summarize the design principles,molecular engineeringstrategies, physical mechanisms and device applications of these two nonfullerene acceptor systems, and propose some possible researchtopics in the nearfuture.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.22375024,21975031,51933001,and 21734009)。
文摘The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.
基金Financial support from the National Natural Science Foundation of China(22375024,21975031,21734009,51933001,22109080,and 52173174)the Natural Science Foundation of Shandong Province(No.ZR2022YQ45)+2 种基金the Taishan Scholars Program(Nos.tstp20221121 and tsqnz20221134)The Beijing Natural Science Foundation(No.2244073)supported by State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)(RZ2200002821)is acknowledged.
文摘A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs.
基金the National Natural Science Foundation of China(Nos.52103352,51925306 and 52120105006)National Key R&D Program of China(No.2018FYA 0305800)+3 种基金Key Research Program of Chinese Academy of Sciences(No.XDPB08-2)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB28000000)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2022165)the Fundamental Research Funds for the Central Universities.
文摘Nonfused ring electron acceptors(NFREAs)have attracted much attention due to their concise synthetic routes and low cost.However,developing high-performance NFREAs with simple structure remains a great challenge.In this work,a simple building block(POBT)with noncovalently conformational locks(No CLs)was designed and synthesized.Single-crystal X-ray study indicated the presence of S…O NOCLs in POBT,thus enabling it to possess a coplanar conformation comparable to that of fused-ring CPT.Two novel NFREAs based on CPT and POBT were developed,namely TT-CPT and TT-POBT,respectively.Besides,TT-POBT possessed a smaller Stokes shift and a reduced reorganization energy compared with TT-CPT,indicating the introduction of S…O No CLs can enhance the molecular rigidity even if simplifying the molecular structure.As a result,the TT-POBT-based PSC device afforded an impressive power conversion efficiency of 11.15%,much higher than that of TT-CPT counterpart(7.03%),mainly resulting from the tighterπ-πstacking,improved and balanced charge transport,and more favorable film morphology.This work demonstrates the potential of the simple building block POBT with No CLs towards constructing low-cost and highperformance NFREAs.
基金financially supported by the National Key Research and Development Program of China (No. 2019YFA0705900) funded by MOSTthe Basic and Applied Basic Research Major Program of Guangdong Province (No. 2019B030302007)the National Natural Science Foundation of China (No. 51521002)。
文摘Non-fullerene polymer solar cells(NF-PSCs) have gained wide attention recently. Molecular design of non-fullerene electron acceptors effectively promotes the photovoltaic performance of NF-PSCs. However,molecular electron acceptors with 2-dimensional(2 D) configuration and conjugation are seldom reported.Herein, we designed and synthesized a series of novel 2 D electron acceptors for efficient NF-PSCs. With rational optimization on the conjugated moieties in both vertical and horizontal direction, these 2 D electron acceptors showed appealing properties, such as good planarity, full-spectrum absorption, high absorption extinction coefficient, and proper blend morphology with donor polymer. A high PCE of 9.76%was achieved for photovoltaic devices with PBDB-T as the donor and these 2 D electron acceptors. It was also found the charge transfer between the conjugated moieties in two directions of these 2 D molecules contributes to the utilization of absorbed photos, resulting in an exceptional EQE of 87% at 730 nm. This work presents rational design guidelines of 2 D electron acceptors, which showed great promise to achieve high-performance non-fullerene polymer solar cells.
基金the financial support by the National Natural Science Foundation of China(51303099)the Natural Science Basic Research Plan in Shaanxi Province of China(2017JM5058)the Funded Projects for the Academic Leaders and Academic Backbones,Shaanxi Normal University(16QNGG008)
文摘Fullerenes and their derivatives are important types of electron acceptor materials and play a vital role in organic solar cell devices. However, the fullerene acceptor material has some difficulties to overcome the intrinsic shortcomings, such as weak absorption in the visible range, difficulty in modification and high cost, which limit the performance of the device and the large-scale application of this type of acceptors. In recent years, non-fullerene electron acceptor material has attracted the attention of scientists due to the advantages of adjustable energy level, wide absorption, simple synthesis, low processing cost and good solubility. Researchers can use the rich chemical means to design and synthesize organic small molecules and their oligomers with specific aggregation morphology and excellent optoelectronic prop- erties. Great advances in the field of synthesis, device engineering, and device physics of non-fullerene acceptors have been achieved in the last few years. At present, non-fullerene small molecules based photovoltaic devices achieve the highest efficiency more than 13% and the efficiency gap between fullerenetype and non-fullerene-type photovoltaic devices is gradually narrowing. In this review, we explore recent progress of non-fullerene small molecule electron acceptors that have been developed and led to highefficiency photovoltaic devices and put forward the prospect of development in the future.
基金The authors gratefully acknowledge the financial support from National Natural Science Foundation of China(NSFC,Nos.51973169 and 52003209)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015)the Science Foundation of Wuhan Institute of Technology(Nos.K202023 and K202025).
文摘Benefitting from the development of non-fullerene acceptors(NFAs),remarkable advances have been achieved with the power conversion efficiency(PCE)exceeding 19%over the last few years.However,the major achievement comes from fused ring electron acceptors(FREAs)with complex structures,leading to high cost.Hence,it is urgent to design new materials to resolve the cost issues concerning basic commercial requirements of organic solar cells.Recently,great progress has been made in fully non-fused ring electron acceptors(NFREAs)with only single-aromatic ring in the electron-donating core,which might achieve a fine balance between the efficiency and cost,thus accelerating the commercial application of organic solar cells.Therefore,this article summarizes the recent advances of fully NFREAs with efficiency over 10%,which may provide a guidance for developing the cost-effective solar cells.
基金This work was financially supported by the National Natural Science Foundation of China(NSFC,Nos.51973032,21905043 and 51833004)the“Chenguang Program”supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.19CG36)+4 种基金the Jiangxi Provincial Natural Science Foundation(Nos.20212ACB203005 and 20212BAB213018)the Thousand Talents Plan of Jiangxi Province(No.jxsq2019101051)the Jiangxi Provincial Education Department Science and Technology Research Foundation(No.GJJ210310)X.Xia and X.Lu acknowledge the financial support from Research Grants Council(RGC)of Hong Kong(General Research Fund No.14303519)Y.Chen expresses thanks for the support from the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DH-D-2021008).
文摘Non-fused ring electron acceptors(NFREAs)have a broad application prospect in the commercialization of organic solar cells(OSCs)due to the advantages of simple synthesis and low cost.The selection of intermediate block cores of non-fused frameworks and the establishment of the relationship between molecular structure and device performance are crucial for the realization of high-performance OSCs.Herein,two A-D-A’-D-A type NFREAs namely CBTBO-4F and CBTBO-4Cl,constructed with a novel electron-deficient block unit N-(2-butyloctyl)-carbazole[3,4-c:5,6-c]bis[1,2,5]thiadiazole(CBT)and bridging unit 4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene(DTC)coupling with different terminals(IC-2F/2Cl),were designed and synthesized.The two NFREAs feature broad and strong photoresponse from 500 nm to 900 nm due to the strong intramolecular charge transfer characteristics.Compared with CBTBO-4F,CBTBO-4Cl shows better molecular planarity,stronger crystallinity,more ordered molecular stacking,larger van der Waals surface,lower energy level and better active layer morphology,contributing to much better charge separation and transport behaviors in its based devices.As a result,the CBTBO-4Cl based device obtains a higher power conversion efficiency of 10.18%with an open-circuit voltage of 0.80 V and a short-circuit current density of 21.20 mA/cm^(2).These results not only demonstrate the great potential of CBT,a new building block of the benzothiazole family,in the construction of high-performance organic conjugated semiconductors,but also suggest that the terminal chlorination is an effective strategy to improve device performance.
基金Project(2022LSL050102)supported by the Laoshan Laboratory,China。
文摘Sulfate and nitrate reducing bacteria are important culprits for microbiologically influenced corrosion(MIC)using sulfate and nitrate as electron acceptors,respectively.Sulfate and nitrate hold different standard electrode potentials,which may lead to differences in corrosion,but their effects on corrosion by the same bacteria have not been reported.The corrosion of Q235 steel affected by Pseudodesulfovibrio cashew(P.cashew)in the sulfate and nitrate media under carbon starvation was studied.It was found that sulfate and nitrate did not lead to differences in corrosion under abiotic conditions.However,P.cashew promoted corrosion in both cases,and the consumption of H_(2)was the main mechanism for MIC.In addition,corrosion was more severe in the sulfate media.The higher corrosivity of P.cashew with sulfate as the electron acceptor is closely related to the higher number of sessile cells in the biofilm,higher bacterial motility,more hydrogen production pathways,and the increased gene expression of enzymes related to energy synthesis.
基金Project supported by the European Regional Development Fund within the Framework of the Innovative Economy Operational Program 2007-2013(No.UDA-POIG.01.03.01-22-140/09-04)the CARbon BALAncing for Nutrient Control in Wastewater Treatment(CARBALA)(No.PIRSES-GA-2011-295176)the National Water Pollution Control and Management of Science and Technology in China(No.2015ZX07218001)
文摘The effects of two different external carbon sources （acetate and ethanol） and electron acceptors （dissolved oxygen, nitrate, and nitrite） were investigated under aerobic and anoxic conditions with non-acclimated process bi- omass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/（g MLVSS.h） （MLVSS： mixed liquor volatile suspended solids）, respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO2-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher deni- trification rates were obtained with acetate （1.4 and 0.8 mg N/（g MLVSS.h）） compared to ethanol （1.1 and 0.7 mg N/ （g MLVSS.h）） for both anoxic electron acceptors （nitrate and nitrite）.
基金Chulalongkorn University Dutsadi Phiphat Scholarshipthe Ratchadapisek Sompoch Endowment Fund(Sci-Super Ⅱ GF_58_08_23_01)the Thailand Research Fund(IRG5780001) for financial support
文摘The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was studied at ambient conditions.In the absence of an electron acceptor,only HO^·radicals were generated by irradiated UV light and TiO2.However,in the presence of the two electron acceptors,both HO^· radical and ^1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor.The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2.The type of generated value-added compounds depended on the concentration of the generated ROS.
基金funded by National Natural Science Foundation of China (No.22125901)the National Key Research and Development Program of China (No.2019YFA0705900)the Fundamental Research Funds for the Central Universities (No.226–2023–00113)。
文摘Developing narrow-bandgap organic semiconductors is important to facilitate the advancement of organic photovoltaics(OPVs). Herein, two near-infrared non-fused ring acceptors(NIR NFRAs), PTBFTT-F and PTBFTT-Cl have been developed with A-π_A-π_D-D-π_D-π_A-A non-fused structures. It is revealed that the introduction of electron deficient π-bridge(π_A) and multiple intramolecular noncovalent interactions effectively retained the structural planarity and intramolecular charge transfer of NFRAs, extending strong NIR photon absorption up to 950 nm. Further, the chlorinated acceptor, with the enlarged π-surface compared to the fluorinated counterpart, promoted not only molecular stacking in solid, but also the desirable photochemical stability in ambient, which are helpful to thereby improve the exciton and charge dynamics for the corresponding OPVs. Overall, this work provides valuable insights into the design of NIR organic semiconductors.
基金supported by the Recruitment Program of Global Youth Experts of Chinasupported by the National Natural Science Foundation of China(Nos. 21574138, 51603209 and 91633301)the Strategic Priority Research Program(No. XDB12030200) of the Chinese Academy of Sciences
文摘In this work, star-shaped perylene bisimide(PBI) derivatives with spiro-aromatic cores linked with ethynyl units were developed as electron acceptors for non-fullerene organic solar cells. The ethynyl linkers were found to enhance the planarity of the conjugated backbone, resulting in high electron mobilities and near-infrared absorption. The ethynyl-linked PBI acceptors showed high power conversion efficiencies(PCEs) up to 4.27% due to the high short-circuit current density(Jsc) of 8.52 mA/cm^2 and fill factor(FF) of 0.59, while the PBI acceptor without ethynyl units provided a low PCE of 3.57% in nonfullerene solar cells. The results demonstrate that ethynyl units can be applied into designing new PBI electron acceptors with improved charge transport properties and photovoltaic performance.
文摘Characteristics of phosphorus removal bacteria were investigated by using three different types of electron acceptors, as well as the positive role of nitrite in phosphorus removal process. An （AO）^2 SBR （anaerobic-aerobic-anoxic-aerobic sequencing batch reactor） was thereby employed to enrich denitrifying phosphorus removal bacteria for simultaneously removing phosphorus and nitrogen via auoxic phosphorus uptake, Ammonium oxidation was controlled at the first phase of the nitrification process. Nitrite-inhibition batch tests illustrated that nitrite was not an inhibitor to phosphorus uptake process, but served as an alternative electron acceptor to nitrate and oxygen if the concentration was under the inhibition level of 40mg NO2 - N·L^- 1. It implied that in addition to the two well-accepted groups of phosphorus removal bacterium （ one can only utilize oxygen as electron acceptor, P1, while the other can use both oxygen and nitrate as electron acceptor, P2 ）, a new group of phosphorus removal bacterium P3, which could use oxygen, nitrate and nitrite as electron acceptor to take up phosphorus were identified in the test system. To understand （AO）^2 SBR sludge better, the relative population of the different bacteria in this system, plus another A/O SBR sludge （ seed sludge） were respectively estimated by the phosphorus uptake batch tests with either oxygen or nitrate or nitrite as electron acceptor. The results demonstrated that phosphorus removal capability of （AO）^2 SBR sludge had a little degradation after A/O sludge was cultivated in the （AO）^2 mode over a long period of time. However, deuitrifying phosphorus removal bacteria （ P2 and P3 ） was significantly enriched showed by the relative population of the three types of bacteria, which implied that energy for aeration and COD consumption could be reduced in theory.
基金supported by the Beijing Natural Science Foundation of China(Z230019,2212005)the National Natural Science Foundation of China(NSFC 22173062,21833005,22090022 and 22275125).
文摘Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a deficiency in understanding the structure-property relationship.Herein,we investigated two low-cost terthiophene-based electron acceptors,namely,3TC8 and 3TEH,with 3,4-bis(octan-3-yloxy)thiophene,differing only in the alkylated thiophene-bridges.Both acceptors exhibit low optical gaps(∼1.43 eV)and possess deep highest occupied molecular orbital(HOMO)levels(∼−5.8 eV).Notably,the single-crystal structure of 3TEH demonstrates highly planar conjugated backbone and strongπ-πstacking between intermolecular terminal groups,attributed to the presence of the bulky alkylated noncovalently conformational locks.Upon utilizing both acceptors to fabricate OSCs,the 3TC8-based device exhibited a power conversion efficiency(PCE)of 11.1%,while the 3TEH-based OSC demonstrated an excellent PCE of 14.4%.This PCE is the highest among OSCs based on terthiophene-containing electron acceptors.These results offer a new strategy for designing low-cost electron acceptors for highly efficient OSCs.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.U21A20101 and 22105208)China Postdoctoral Science Foundation(No.2021M703263).
文摘We synthesize and compare four near-infrared absorbing fused-ring electron acceptors named as nTTIC(n=2,3,4,and 5),based on different number of thieno[3,2-b]thiophene(TT)unit as the electron-donating core.With increasing the TT unit,absorption spectrum of the TTIC series red shifts,and the highest occupied molecular orbital(HOMO)upshifts notably.It is worth noting that 4TTIC and 5TTIC exhibit absorption edges approaching 1100 nm,which is the photoresponse limit of solar cells based on crystal silicon.When the TTIC series acceptors are blended with polymer donor PM6,the binary-blend organic solar cells based on 3TTIC show the best power conversion efficiency(PCE)of 13.1%.In contrast,2TTIC-based devices exhibit relatively lower PCE of 8.32%,mainly caused by the larger energy loss and blue-shifted absorption.Due to insufficient driving force of charge separation caused by very high HOMO,4TTIC and 5TTIC show poor PCEs lower than 3%.
基金Natural Science Foundation of Zhejiang Province(No R15B010001)National Natural Science Foundation of China(No 21701143)。
文摘Metal-organic framework(MOF)photocatalysts have shown promising application in photocatalytic Cr(VI)reduction,but their activities are still restrained by severe charge recombination.To overcome this limitation,herein we propose that the incorporation of cocatalysts as electron acceptors inside MOF pores can provide a better chance to separate the photogenerated electrons,compared with traditional methods to cover cocatalysts on the MOF surface.Following this strategy,we demonstrate a facile method to in situ generate carbon quantum dots(CQDs)as cocatalysts inside a typical MOF photocatalyst(MIL-53(Fe)).The CQDs can serve as efficient localized electron acceptors for separating the photogenerated carriers from the inner metal-oxo clusters among the MOFs,and thus their photocatalytic activities can be greatly improved.Besides acting as electron acceptors,we also reveal that the CQDs can work as photosensitizers for the MOF particles under long-wavelength light irradiation,playing a second role to enhance their activities.The MIL-53(Fe)/CQD composites have been well characterized and their photocatalytic mechanism has been proposed.
基金supported by the National Natural Science Foundation of China(grant nos.22475062 and 22075069)Natural Science Foundation of Henan Province(grant no.212300410002)Program sponsored by Henan Province(grant no.23ZX002),Post-graduate Education Reform and Quality Improvement Project of Henan Province(grant no.YJS2025AL100).
文摘Bulky aromatic side groups are an effective strategy for the design of highly efficient fully nonfused electron acceptors(FNEAs)by creating spatial confinement to achieve backbone planarity.However,theπ-πinteractions between the steric aromatic groups can induce single bond rotation and form a twisting molecular configuration.Hence,it’s crucial to improve the positive planarization effect and inhibit the unfavorableπ-πinteracted competition from the steric groups.Herein,we designed and synthesized a series of tetrathiophene-based FNEAs,namely 4T-C2,4TC3,4T-C4,and 4T-C5,by precisely regulating the length of the alkyl side chain by systematically increasing it by one atom.Among the four FNEAs,only the n-propyl functionalized 4T-C3 accomplished a planar molecular backbone,which produced a highly interconnected three-dimensional charge transport network,confirmed by the single crystal characterization.Molecular dynamics simulations provided a deeper understanding of this structural variation,and results indicate that the length of alkyl-substituted side chains significantly influences intermolecular interaction,thereby achieving controllable regulation at molecular conformation.Finally,4T-C3 achieved outstanding power conversion efficiencies of 14.88%and 19.54%for binary and ternary organic solar cells,respectively.Overall,this work provides a systematic understanding and precise conformation regulation strategy for FNEAs design.
基金supported by the National Key Research and Development Program of China(2022YFE0132400)the National Natural Science Foundation of China(NSFC)(22209131 and 22405204)+6 种基金the Key Scientific and Technological Innovation Team Project of Shaanxi Province(2020TD-002)the 111 project 2.0(BP0618008)the Postdoctoral Innovation Talents Support Program(BX20230285)the Science and Technology Program of Shaanxi Province(2023-JC-QN-0448)the Outstanding Youth Science and Technology Fund Project of Xi’an University of Science and Technology(8159922001)the Open Fund of Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications(Changzhou University)(GDRGCS2023002)supported by the Director,Office of Science,Office of Basic Energy Sciences of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘The development of high-performance nearinfrared(NIR)absorbing electron acceptors is a major challenge in achieving high short-circuit current density(JSC)to increase power conversion efficiency(PCE)of organic solar cells(OSCs).Herein,three new multi-heteroatomized Y-series acceptors(bi-asy-Y-Br,bi-asy-Y-FBr,and bi-asy-Y-FBrF)were developed by combining dual-asymmetric selenium-fused core and brominated end-groups with different numbers of fluorine substitutions.With gradually increasing fluorination,three acceptors exhibit red-shift absorption.Among them,biasy-Y-FBrF presents planar molecular geometry,the maximum average electrostatic potential,and the minimum molecular dipole moment,which are conducive to intramolecular packing and charge transport.Moreover,D18:bi-asy-Y-FBrF active layer presents higher crystallinity,more suitable phase separation,and reduced charge recombination compared to D18:bi-asy-Y-Br and D18:bi-asy-Y-FBr blends.Consequently,among theses binary OSCs,D18:bi-asy-Y-FBrF device achieves a higher PCE of 15.74% with an enhanced JSC of 26.28 mA cm^(-2),while D18:bi-asy-Y-Br device obtains a moderate PCE of 15.04% with the highest open-circuit voltage(VOC)of 0.926 V.Inspired by its high VOC and complementary absorption with NIR-absorbing BTP-eC9 as acceptor,bi-asy-Y-Br is introduced into binary D18:BTP-eC9 to construct ternary OSCs,achieving a further boosted PCE of 19.12%,which is among the top values for the reported green solvent processed OSCs.
基金National Natural Science Foundation of China(22275058,U20A6002,and 22405092)National Key Research and Development Program funded by the Ministry of Science and Technology of China(2019YFA0705900)+4 种基金Guangdong Basic and Applied Basic Research Foundation(2022B1515120008)Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08L075)State Key Lab of Luminescent Materials and Devices(Skllmd-2023-10)Start-up Founding Project funded by Ningbo University of Technology(2022KQ65)General Scientific Research Project of Zhejiang Education Department(Y202456587)。
文摘The A–D–A′–D–A-type non-fused ring electron acceptors(NFREAs),consisting of electron-donating unit(D)as the bridge to link electron-accepting units(A and A′),have emerged as promising electron acceptors for organic solar cells(OSCs)and organic photodetectors(OPDs).As the units are linked by the carbon–carbon single bonds,these electron acceptors generally possess feasible synthesis and tunable optoelectronic properties.Herein,the recent progress of A–D–A′–D–A-type NFREAs is reviewed,including molecular design,device performance,structure–property relationships,and their applications in OSCs and OPDs.Finally,we discuss the challenges and propose the perspectives for the further development of A–D–A′–D–A-type NFREAs.
基金This work is supported by the National Natural Science Foundation of China(U21A20101).
文摘Fullerene derivatives are classic electron acceptor materials for organic solar cells (Oscs) but possess some intrinsic drawbacks such as weak visiblelightabsorption,limitedoptoelectronic property tunability,dificult purification and photochemical/morphological instability.Fullereneacceptors area bottleneck restricting further development of this field. Ourgroup pioneered the exploration of novel nonfulerene acceptors in China in 2006,andinitiated the research of two representative acceptor systems, rylene dimide polymer and fused-ring electron acceptor (FREA).FREA breaks the theoreticalefficiencylimit of fullerene-based OsCs (-13%) and promotes the whole field to an unprecedented prosperity with efficiency of 20%, heraldinga nonfullerene era for OsCs.In this review, we revisit 15-year nonfullerene exploration journey,summarize the design principles,molecular engineeringstrategies, physical mechanisms and device applications of these two nonfullerene acceptor systems, and propose some possible researchtopics in the nearfuture.
