In the field of organic solar cells(OSCs),side-chain engineering is a key strategy for developing high-performance non-fullerene small molecule acceptors(SMAs),which could adjust the material solubility and modulate t...In the field of organic solar cells(OSCs),side-chain engineering is a key strategy for developing high-performance non-fullerene small molecule acceptors(SMAs),which could adjust the material solubility and modulate the intermolecular stacking properties,profoundly impacting the film morphology and thus acting on the final power conversion efficiency(PCE) of the materials.In this study,two asymmetric acceptor molecules,Qx-Ph Br-BO and Qx-Ph Br-X,were synthesized by migrating the branching site of the outer side chain from the β-site to the γ-site.The branching site located at the γ-site could reduce the steric-hindrance effect and enhance the molecular aggregation behavior,giving rise to redshifted absorption and tight π-π stacking.Morphology analysis shows that the Qx-Ph Br-X-based devices have smoother surfaces and a phase-separated structure,which is more favorable for charge transport and extraction.The Qx-Ph Br-X-based devices exhibit balanced hole-electron mobility,efficient exciton dissociation,and low charge recombination.As a result,Qx-Ph Br-X with γ-site branching exhibits superior photovoltaic performance with a PCE of 17.16 %,which is significantly higher than that of Qx-Ph Br-BO at 16.28 %.These results highlight the importance of side-chain modifications for optimizing OSC efficiency and provide an important reference for precise tuning of side-chain structures in future molecular design.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
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
Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge ...Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.展开更多
The integration of advanced diagnostic and therapeutic capabilities in oncology has given rise to phototheranostics,a field that combines the precision of imaging with the selectivity of light-activated treatments.Due...The integration of advanced diagnostic and therapeutic capabilities in oncology has given rise to phototheranostics,a field that combines the precision of imaging with the selectivity of light-activated treatments.Due to their pronounced near-infrared(NIR)absorption,tunable molecular structures,and commendable stability,organic photovoltaic non-fullerene acceptors(NFAs)represent a promising frontier in cancer management.Despite the great potential of NFAs in phototheranostics,there is currently a lack of systematic reviews in this field.This review provides a meticulous examination of the current state of NFAs in the field of phototheranostics,highlighting the strategic approaches to spectral red-shifting that enhance tissue penetration and therapeutic efficacy.It dissects the link between molecular architecture and performance across key therapeutic and diagnostic modalities,including photothermal therapy(PTT),photodynamic therapy(PDT),and fluorescence imaging(FLI).In addition,the review presents a concise analysis of the challenges and milestones in the clinical translation of NFAs,offering insights into the innovations required to overcome existing barriers.展开更多
Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationshi...Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationship is of great significance.Herein,we explored the chlorination effect of the side chain on the terminals.We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs,BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups.We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors,affording high photovoltage and photocurrent.With the stepwise chlorination,the open-circuit voltage(V_(OC))values decrease from 1.28,1.22,to 1.20 V,while the corresponding power conversion efficiencies(PCEs)improve from 5.07%,9.15%,to 10.96%.Compared with BTA5-based OSCs,introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss(0.14<0.17<0.19 e V),resulting in a sequential decrease in VO C.However,more chlorine atom replacements produce more effective exciton dissociation,higher charge transfer,and balanced carrier mobility in the blend films,ultimately achieving better PCEs.This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance,implying good application potential in indoor photovoltaics.展开更多
High-voltage lithium(Li)metal batteries(LMBs)face substantial challenges,including Li dendrite growth and instability in high-voltage cathodes such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811),which impede their practic...High-voltage lithium(Li)metal batteries(LMBs)face substantial challenges,including Li dendrite growth and instability in high-voltage cathodes such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811),which impede their practical applications and long-term stability.To address these challenges,tris(pentafluorophenyl)borane additive as an electron acceptor is introduced into an ethyl methyl carbonate/fluoroethylene carbonate-based electrolyte.This approach effectively engineers robust dual interfaces on the Li metal anode and the NCM811 cathode,thereby mitigating dendritic growth of Li and enhancing the stability of the cathode.This additive-driven strategy enables LMBs to operate at ultra-high voltages up to 4.7 V.Consequently,Li||Cu cells achieve a coulombic efficiency of 98.96%,and Li||Li symmetric cells extend their cycle life to an impressive 4000 h.Li||NCM811 full cells maintain a high capacity retention of 87.8%after 100 cycles at 4.7 V.Additionally,Li||LNMO full cells exhibit exceptional rate capability,delivering 132.2 mAh g^(-1)at 10 C and retaining 95.0%capacity after 250 cycles at 1 C and 5 V.As a result,NCM811||graphite pouch cells maintain a 93.4%capacity retention after 1100 cycles at 1 C.These findings underscore the efficacy of additive engineering in addressing Li dendrite formation and instability of cathode under high voltage,thereby paving the road for durable,high-performance LMBs.展开更多
The asymmetric molecular design strategy,with advantages in modulating the molecular dipole moment and intermolecular interactions and achieving more favorable molecular packing and orientation,has been an effective a...The asymmetric molecular design strategy,with advantages in modulating the molecular dipole moment and intermolecular interactions and achieving more favorable molecular packing and orientation,has been an effective approach for designing high-performance nonfullerene acceptors(NFAs).Herein,two asymmetric NFAs,Y-CN-2F and Y-CN-2Cl,were designed and synthesized by introducing a linear alkyl chain terminated with the 4-cyanobiphenyl group,a well-known mesogenic unit,at one of the inner pyrrole positions instead of the normal 2-butyloctyl branched alkyl chain.The difference between Y-CN-2F and Y-CN-2Cl is the terminated IC-groups,which was modified with F and Cl halogens,respectively.Both NFAs displayed strong absorption in the near-infrared to visible-light range,which is complementary to that of typical medium-bandgap donor polymers.After optimization with D18 donor in organic solar cells(OSCs),Y-CN-2F and Y-CN-2Cl provided comparable power conversion efficiencies(PCEs)of 15.33%and 15.88%.While the D18:Y-CN-2F based devices displayed higher fill factors(FFs),those based on D18:Y-CN-2Cl exhibited higher current densities and open-circuit voltages.The Y-CN-2Cl film showed longer light absorption than YCN-2F,which is beneficial for more light harvesting.Moreover,D18:Y-CN-2Cl displayed a lower fluorescence lifetime and faster carrier transfer processes,which could be attributed to its higher mobility.For the D18:Y-CN-2F blended film,a more pronounced fiber network structure and balanced carrier mobility were observed,which contributed to the higher FFs values.This work presents new efforts to develop more asymmetric NFAs with specific functional segments for efficient organic electronics.展开更多
A research team led by Dr.GE Ziyi from the Ningbo Institute of Materials Technology and Engineering(NIMTE)of the Chinese Academy of Sciences has developed novel giant acceptors with an oxygenated linker,enabling the c...A research team led by Dr.GE Ziyi from the Ningbo Institute of Materials Technology and Engineering(NIMTE)of the Chinese Academy of Sciences has developed novel giant acceptors with an oxygenated linker,enabling the creation of highly efficient non-halogen-processed organic solar cells(OSCs),with a power conversion efficiency(PCE)up to 20.02%.展开更多
Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structura...Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structural design to optimize the blend morphology remains challenging.Herein,we present a simple yet effective design strategy to modulate the aggregation behavior of the Y-series-based polymer acceptor PY-V-γby introducing a pendant-fluorinated Y-series acceptor(Y2F-ET)into the main-conjugated backbone.Two random copolymer acceptors(PY-EY-5 and PY-EY-20)were synthesized with varying molar fractions of Y2F-ET pendant monomers.Our findings revealed that both the solution-phase and solid-state aggregation behaviors were progressively suppressed as the Y2F-ET content increased.Compared to the highly self-aggregating PY-V-γ-based all-PSCs,the more amorphous PY-EY-5 enabled devices to achieve an increased device efficiency from 17.31%to 18.45%,which is attributed to the slightly smaller polymer phase-separation domain sizes and reduced molecular aggregation in the PM6:PY-EY-5 blend.Moreover,the finely tuned blend morphology exhibited superior thermal stability,underscoring the significant advantages of the Y-series pendant random copolymerization approach.展开更多
The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highes...The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highest occupied molecular orbital(HOMO)level and low degree of crystallinity of the star donor polymer PCE10 limit its application in PDI-based Organic solar cells(OSCs).In this study,two benzo[1,2-b:4,5-b′]difuran(BDF)-based narrow-bandgap polymer donors,PBDF and PBDFCl,were synthesized to improve the photovoltaic performance of PDI-based OSCs.The smaller BDF moiety with higher electronegativity endows the resulting polymers with stronger aggregation and lower HOMO energy levels.The power conversion efficiency(PCE)value of the PBDF:Ph(PDI)3-based OSCs was 7.24%,which is much higher than that of PCE10-based OSCs(6.09%).Further chlorination of the conjugated side chain elevated the PCE to 8.84%,which is 1.4 times higher than that of PCE10-based OSCs.These results demonstrate the significant contribution of designing novel narrow-bandgap polymer donors to boost the PCE of PDI-based OSCs and highlight the importance of matching the aggregation behaviors of polymeric donor materials with that of NFAs.展开更多
基金the financial support by the Beijing Natural Science Foundation (No.Z230018)the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB0520102)CAS Project for Young Scientists in Basic Research (No.YSBR-102)。
文摘In the field of organic solar cells(OSCs),side-chain engineering is a key strategy for developing high-performance non-fullerene small molecule acceptors(SMAs),which could adjust the material solubility and modulate the intermolecular stacking properties,profoundly impacting the film morphology and thus acting on the final power conversion efficiency(PCE) of the materials.In this study,two asymmetric acceptor molecules,Qx-Ph Br-BO and Qx-Ph Br-X,were synthesized by migrating the branching site of the outer side chain from the β-site to the γ-site.The branching site located at the γ-site could reduce the steric-hindrance effect and enhance the molecular aggregation behavior,giving rise to redshifted absorption and tight π-π stacking.Morphology analysis shows that the Qx-Ph Br-X-based devices have smoother surfaces and a phase-separated structure,which is more favorable for charge transport and extraction.The Qx-Ph Br-X-based devices exhibit balanced hole-electron mobility,efficient exciton dissociation,and low charge recombination.As a result,Qx-Ph Br-X with γ-site branching exhibits superior photovoltaic performance with a PCE of 17.16 %,which is significantly higher than that of Qx-Ph Br-BO at 16.28 %.These results highlight the importance of side-chain modifications for optimizing OSC efficiency and provide an important reference for precise tuning of side-chain structures in future molecular design.
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supported by NSFC(22271282)the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences with the grant number of CXZX-2022-JQ04.
文摘Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.
基金supported by the Natural Science Foundation of Zhejiang Province(Nos.LZ23B040001,LY23E030003 and LY24B030005)the National Natural Science Foundation of China(No.22105222)+1 种基金the Interdisciplinary Research Project of Hangzhou Normal University(No.2024JCXK05)the Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application,Soochow University。
文摘The integration of advanced diagnostic and therapeutic capabilities in oncology has given rise to phototheranostics,a field that combines the precision of imaging with the selectivity of light-activated treatments.Due to their pronounced near-infrared(NIR)absorption,tunable molecular structures,and commendable stability,organic photovoltaic non-fullerene acceptors(NFAs)represent a promising frontier in cancer management.Despite the great potential of NFAs in phototheranostics,there is currently a lack of systematic reviews in this field.This review provides a meticulous examination of the current state of NFAs in the field of phototheranostics,highlighting the strategic approaches to spectral red-shifting that enhance tissue penetration and therapeutic efficacy.It dissects the link between molecular architecture and performance across key therapeutic and diagnostic modalities,including photothermal therapy(PTT),photodynamic therapy(PDT),and fluorescence imaging(FLI).In addition,the review presents a concise analysis of the challenges and milestones in the clinical translation of NFAs,offering insights into the innovations required to overcome existing barriers.
基金support from the National Natural Science Foundation of China(Nos.52373176,52073067)。
文摘Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationship is of great significance.Herein,we explored the chlorination effect of the side chain on the terminals.We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs,BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups.We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors,affording high photovoltage and photocurrent.With the stepwise chlorination,the open-circuit voltage(V_(OC))values decrease from 1.28,1.22,to 1.20 V,while the corresponding power conversion efficiencies(PCEs)improve from 5.07%,9.15%,to 10.96%.Compared with BTA5-based OSCs,introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss(0.14<0.17<0.19 e V),resulting in a sequential decrease in VO C.However,more chlorine atom replacements produce more effective exciton dissociation,higher charge transfer,and balanced carrier mobility in the blend films,ultimately achieving better PCEs.This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance,implying good application potential in indoor photovoltaics.
基金financially supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000002)the Shenzhen Key Laboratory of Advanced Energy Storage(ZDSYS20220401141000001)the High level of special funds(G03034K001)。
文摘High-voltage lithium(Li)metal batteries(LMBs)face substantial challenges,including Li dendrite growth and instability in high-voltage cathodes such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811),which impede their practical applications and long-term stability.To address these challenges,tris(pentafluorophenyl)borane additive as an electron acceptor is introduced into an ethyl methyl carbonate/fluoroethylene carbonate-based electrolyte.This approach effectively engineers robust dual interfaces on the Li metal anode and the NCM811 cathode,thereby mitigating dendritic growth of Li and enhancing the stability of the cathode.This additive-driven strategy enables LMBs to operate at ultra-high voltages up to 4.7 V.Consequently,Li||Cu cells achieve a coulombic efficiency of 98.96%,and Li||Li symmetric cells extend their cycle life to an impressive 4000 h.Li||NCM811 full cells maintain a high capacity retention of 87.8%after 100 cycles at 4.7 V.Additionally,Li||LNMO full cells exhibit exceptional rate capability,delivering 132.2 mAh g^(-1)at 10 C and retaining 95.0%capacity after 250 cycles at 1 C and 5 V.As a result,NCM811||graphite pouch cells maintain a 93.4%capacity retention after 1100 cycles at 1 C.These findings underscore the efficacy of additive engineering in addressing Li dendrite formation and instability of cathode under high voltage,thereby paving the road for durable,high-performance LMBs.
基金financially supported by the National Natural Science Foundation of China(Nos.22465018,52163018 and 22405107)of ChinaJiangxi Provincial Department of Science and Technology(Nos.20232BBE50026,jxsq2023102153,20232BAB21302 and 2024SSY05132)Jiangxi Academy of Sciences(Nos.2023YYB07,2022YSBG22031,2022YJC2019,2022YJC2017,2023YSBG21017,2022YYB10,2022YRCS002,2023YJC1001,and 2023YSBG22025)。
文摘The asymmetric molecular design strategy,with advantages in modulating the molecular dipole moment and intermolecular interactions and achieving more favorable molecular packing and orientation,has been an effective approach for designing high-performance nonfullerene acceptors(NFAs).Herein,two asymmetric NFAs,Y-CN-2F and Y-CN-2Cl,were designed and synthesized by introducing a linear alkyl chain terminated with the 4-cyanobiphenyl group,a well-known mesogenic unit,at one of the inner pyrrole positions instead of the normal 2-butyloctyl branched alkyl chain.The difference between Y-CN-2F and Y-CN-2Cl is the terminated IC-groups,which was modified with F and Cl halogens,respectively.Both NFAs displayed strong absorption in the near-infrared to visible-light range,which is complementary to that of typical medium-bandgap donor polymers.After optimization with D18 donor in organic solar cells(OSCs),Y-CN-2F and Y-CN-2Cl provided comparable power conversion efficiencies(PCEs)of 15.33%and 15.88%.While the D18:Y-CN-2F based devices displayed higher fill factors(FFs),those based on D18:Y-CN-2Cl exhibited higher current densities and open-circuit voltages.The Y-CN-2Cl film showed longer light absorption than YCN-2F,which is beneficial for more light harvesting.Moreover,D18:Y-CN-2Cl displayed a lower fluorescence lifetime and faster carrier transfer processes,which could be attributed to its higher mobility.For the D18:Y-CN-2F blended film,a more pronounced fiber network structure and balanced carrier mobility were observed,which contributed to the higher FFs values.This work presents new efforts to develop more asymmetric NFAs with specific functional segments for efficient organic electronics.
文摘A research team led by Dr.GE Ziyi from the Ningbo Institute of Materials Technology and Engineering(NIMTE)of the Chinese Academy of Sciences has developed novel giant acceptors with an oxygenated linker,enabling the creation of highly efficient non-halogen-processed organic solar cells(OSCs),with a power conversion efficiency(PCE)up to 20.02%.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22279094 and 22409149)Hubei Provincial Natural Science Foundation(No.2024 AFB068)Fundamental Research Funds for the Central Universities。
文摘Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structural design to optimize the blend morphology remains challenging.Herein,we present a simple yet effective design strategy to modulate the aggregation behavior of the Y-series-based polymer acceptor PY-V-γby introducing a pendant-fluorinated Y-series acceptor(Y2F-ET)into the main-conjugated backbone.Two random copolymer acceptors(PY-EY-5 and PY-EY-20)were synthesized with varying molar fractions of Y2F-ET pendant monomers.Our findings revealed that both the solution-phase and solid-state aggregation behaviors were progressively suppressed as the Y2F-ET content increased.Compared to the highly self-aggregating PY-V-γ-based all-PSCs,the more amorphous PY-EY-5 enabled devices to achieve an increased device efficiency from 17.31%to 18.45%,which is attributed to the slightly smaller polymer phase-separation domain sizes and reduced molecular aggregation in the PM6:PY-EY-5 blend.Moreover,the finely tuned blend morphology exhibited superior thermal stability,underscoring the significant advantages of the Y-series pendant random copolymerization approach.
基金supported by the National Natural Science Foundation of China(Nos.52273195 and 51973169)Young Top-notch Talent Cultivation Program of Hubei Province,Natural Science Foundation of Hubei Province(No.2022CFB097)。
文摘The development of narrow-bandgap polymer donors with complementary absorption and matched energy levels for perylene diimides(PDI)-based nonfullerene acceptors(NFAs)has received little attention.The high-lying highest occupied molecular orbital(HOMO)level and low degree of crystallinity of the star donor polymer PCE10 limit its application in PDI-based Organic solar cells(OSCs).In this study,two benzo[1,2-b:4,5-b′]difuran(BDF)-based narrow-bandgap polymer donors,PBDF and PBDFCl,were synthesized to improve the photovoltaic performance of PDI-based OSCs.The smaller BDF moiety with higher electronegativity endows the resulting polymers with stronger aggregation and lower HOMO energy levels.The power conversion efficiency(PCE)value of the PBDF:Ph(PDI)3-based OSCs was 7.24%,which is much higher than that of PCE10-based OSCs(6.09%).Further chlorination of the conjugated side chain elevated the PCE to 8.84%,which is 1.4 times higher than that of PCE10-based OSCs.These results demonstrate the significant contribution of designing novel narrow-bandgap polymer donors to boost the PCE of PDI-based OSCs and highlight the importance of matching the aggregation behaviors of polymeric donor materials with that of NFAs.
