Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challengin...Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challenging.Herein, wide bandgap polymer donor PTzBI-dF is demonstrated as an effectivemodulator for enhancing the crystallinity of the bulk heterojunction active layerscomposed of D18 derivatives blended with Y6, leading to dense and orderedmolecular packings, and thus, improves photoluminescence quenching properties.As a result, the photovoltaic devices exhibit reduced trap-assisted charge recombinationlosses, achieving an optimized power conversion efficiency of over 19%.Besides the efficiency enhancement, the devices comprised of PTzBI-dF as athird component simultaneously attain decreased current leakage, improved chargecarrier mobilities, and suppressed bimolecular charge recombination, leading toreduced energy losses. The advanced crystalline structures induced by PTzBI-dFand its characteristics, such as well-aligned energy level, and complementaryabsorption spectra, are ascribed to the promising performance improvements.Our findings suggest that donor phase engineering is a feasible approach to tuning the molecular packings in the active layer, providingguidelines for designing effective morphology modulators for high-performance organic solar cells.展开更多
The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.H...The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.However,achieving precise control over this packaging structure presents a considerable challenge.Herein,we propose a dual additive strategy utilizing dibenzofuran and halogenated naphthalene to systematically manipulate molecular packing orientation and enhance the long-range molecular packing order of the acceptors.Dibenzofuran is crucial in promoting crystallinity within the material,facilitating the formation of an ordered structure,while halogenated naphthalene regulates the orientation of the molecules,ensuring proper alignment.Specifically,the combination of dibenzofuran and 1-chloronaphthalene promotes edge-on molecular packing and enhances the formation of nanofibrillar structures with improved order,leading to improved charge transport and device performance.Implementing this strategy in devices composed of PM6 and L8-BO has yielded a power conversion efficiency of 19.58%,accompanied by long-term stability.Similarly,1-fluoronaphthalene has also demonstrated effectiveness in improving molecular orientation and overall device efficiency,demonstrating the robustness of this dual additive strategy.By addressing the challenges associated with molecular packing and orientation in active layers,our result contributes valuable insights into optimizing organic solar cells for practical applications.展开更多
When used in organic solar cells,poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)aligns interfacial energy levels,promotes hole extraction,blocks electrons,and optimizes the active layer’s morpholog...When used in organic solar cells,poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)aligns interfacial energy levels,promotes hole extraction,blocks electrons,and optimizes the active layer’s morphology.However,with an optimal thickness of approximately 30-40 nm,PEDOT:PSS has insufficient layer thickness tolerance,owing to its low conductivity and hole extraction property.Herein,a hole-selective-molecule doping strategy is proposed to enhance the properties of PEDOT:PSS by introducing MPA2FPh-BT-BA(abbreviated as 2F)into its layer.2F assembles at the anode to form interfacial dipoles due to its unique donor-acceptor-anchor molecular configuration,altering the anode work function and hole-selective extraction.Additionally,2F improves the aggregation properties of PEDOT:PSS by forming hydrogen bonds with the PSS group,enhancing the conductivity characteristics.These changes in the PEDOT:PSS layer further influence the overlaying morphology,leading to increased crystalline features of PM6 and the bulk heterojunction of PM6:Y6.When a 2F-PEDOT:PSS(2FPP)layer is used,power conversion efficiencies of 18.3%,19.2%,and 19.1%are achieved in PM6:Y6,PM6:BTP-eC9,and PM6:L8-BO devices,respectively,outperforming counterparts with PEDOT:PSS.Specifically,the performance of PM6:Y6 devices with a 2FPP layer of 170 nm remains at>15%,providing valuable guidance for designing a thickness-insensitive hole transport layer for high-efficiency organic solar cells.展开更多
Understanding the photophysical interactions between the components in organic-inorganic nanocomposites is a key factor for their efficient application in optoelectronic devices. In particular, the photophysical study...Understanding the photophysical interactions between the components in organic-inorganic nanocomposites is a key factor for their efficient application in optoelectronic devices. In particular, the photophysical study of nanocomposites based on organic conjugated polymers is rare. We investigated the effect of surface plasmon resonance(SPR) of gold nanoparticles(Au NPs) on the photoluminescence(PL) property of a push-pull conjugated polymer(PBDB-T). We prepared the hybrid system by incorporating poly(3-hexylthiophene)-stabilized Au NPs(P3 HT-Au NPs) into PBDB-T. The enhanced and blueshifted PL was observed in the hybrid system compared to PL in a neat PBDB-T system, indicating that the P3 HT chains attached to the Au NPs suppressed charge-transfer from PBDB-T to the Au NPs and relayed the hot electrons to PBDB-T(the band-filling effect).This photophysical phenomenon limited the auto-dissociation of PBDB-T excitons. Thus, the radiative recombination of the excitons occurred more in our hybrid system than in the neat system.展开更多
Despite recent dramatic improvements in the electronic characteristics of stretchable organic fieldeffect transistors(FETs),their low operational stability remains a bottleneck for their use in practical applications....Despite recent dramatic improvements in the electronic characteristics of stretchable organic fieldeffect transistors(FETs),their low operational stability remains a bottleneck for their use in practical applications.Here,the operational stability,especially the bias-stress stability,of semiconducting polymer-based FETs under various tensile strains is investigated.Analyses on the structure of stretched semiconducting polymer films and spectroscopic quantification of trapped charges within them reveal the major cause of the strain-dependent bias-stress instability of the FETs.Devices with larger strains exhibit lower stability than those with smaller strains because of the increased water content,which is accompanied by the formation of cracks and nanoscale cavities in the semiconducting polymer film as results of the applied strain.The strain-dependence of bias-stress stability of stretchable OFETs can be eliminated by passivating the devices to avoid penetration of water molecules.This work provides new insights for the development of bias-stable stretchable OFETs.展开更多
基金support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2023GXNSFFA026004 and 2022GXNSFDA035066)+2 种基金the Innovation Project of Guangxi Graduate Education(YCBZ2024034)Natural Science Foundation of Ningbo under grant(2022J149)Natural Science Foundation of Ningbo under grant(2022A-230-G)
文摘Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challenging.Herein, wide bandgap polymer donor PTzBI-dF is demonstrated as an effectivemodulator for enhancing the crystallinity of the bulk heterojunction active layerscomposed of D18 derivatives blended with Y6, leading to dense and orderedmolecular packings, and thus, improves photoluminescence quenching properties.As a result, the photovoltaic devices exhibit reduced trap-assisted charge recombinationlosses, achieving an optimized power conversion efficiency of over 19%.Besides the efficiency enhancement, the devices comprised of PTzBI-dF as athird component simultaneously attain decreased current leakage, improved chargecarrier mobilities, and suppressed bimolecular charge recombination, leading toreduced energy losses. The advanced crystalline structures induced by PTzBI-dFand its characteristics, such as well-aligned energy level, and complementaryabsorption spectra, are ascribed to the promising performance improvements.Our findings suggest that donor phase engineering is a feasible approach to tuning the molecular packings in the active layer, providingguidelines for designing effective morphology modulators for high-performance organic solar cells.
基金the financial support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2023GXNSFFA026004)+2 种基金the Guangxi Talent Program("Highland of Innovation Talents")the Shenzhen High-tech Development Special Plan-Pingshan Districts Innovation Platform Project(29853M-KCJ-2023-002-04)Industry and Energy(MOTIE),Republic of Korea(Project No.:RS-2025-02413058)。
文摘The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.However,achieving precise control over this packaging structure presents a considerable challenge.Herein,we propose a dual additive strategy utilizing dibenzofuran and halogenated naphthalene to systematically manipulate molecular packing orientation and enhance the long-range molecular packing order of the acceptors.Dibenzofuran is crucial in promoting crystallinity within the material,facilitating the formation of an ordered structure,while halogenated naphthalene regulates the orientation of the molecules,ensuring proper alignment.Specifically,the combination of dibenzofuran and 1-chloronaphthalene promotes edge-on molecular packing and enhances the formation of nanofibrillar structures with improved order,leading to improved charge transport and device performance.Implementing this strategy in devices composed of PM6 and L8-BO has yielded a power conversion efficiency of 19.58%,accompanied by long-term stability.Similarly,1-fluoronaphthalene has also demonstrated effectiveness in improving molecular orientation and overall device efficiency,demonstrating the robustness of this dual additive strategy.By addressing the challenges associated with molecular packing and orientation in active layers,our result contributes valuable insights into optimizing organic solar cells for practical applications.
基金support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2022GXNSFDA035066 and 2023GXNSFFA026004)+3 种基金the Innovation Project of Guangxi Graduate Education(YCBZ2024034)supported by the National Research Foundation(NRF)of Korea(2020R1A2C3004477)Natural Science Foundation of Ningbo under grant No.2022J149Natural Science Foundation of Ningbo under grant No.2022A-230-G.
文摘When used in organic solar cells,poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)aligns interfacial energy levels,promotes hole extraction,blocks electrons,and optimizes the active layer’s morphology.However,with an optimal thickness of approximately 30-40 nm,PEDOT:PSS has insufficient layer thickness tolerance,owing to its low conductivity and hole extraction property.Herein,a hole-selective-molecule doping strategy is proposed to enhance the properties of PEDOT:PSS by introducing MPA2FPh-BT-BA(abbreviated as 2F)into its layer.2F assembles at the anode to form interfacial dipoles due to its unique donor-acceptor-anchor molecular configuration,altering the anode work function and hole-selective extraction.Additionally,2F improves the aggregation properties of PEDOT:PSS by forming hydrogen bonds with the PSS group,enhancing the conductivity characteristics.These changes in the PEDOT:PSS layer further influence the overlaying morphology,leading to increased crystalline features of PM6 and the bulk heterojunction of PM6:Y6.When a 2F-PEDOT:PSS(2FPP)layer is used,power conversion efficiencies of 18.3%,19.2%,and 19.1%are achieved in PM6:Y6,PM6:BTP-eC9,and PM6:L8-BO devices,respectively,outperforming counterparts with PEDOT:PSS.Specifically,the performance of PM6:Y6 devices with a 2FPP layer of 170 nm remains at>15%,providing valuable guidance for designing a thickness-insensitive hole transport layer for high-efficiency organic solar cells.
基金National Research Foundation of Korea(NRF-2020R1I1A1A01054660)KRICT core project(SS2042)Ministry of Science and ICT,South Korea(NRF-2019M3D1A1078304,NRF-2019R1A2B5B02070657)。
文摘Understanding the photophysical interactions between the components in organic-inorganic nanocomposites is a key factor for their efficient application in optoelectronic devices. In particular, the photophysical study of nanocomposites based on organic conjugated polymers is rare. We investigated the effect of surface plasmon resonance(SPR) of gold nanoparticles(Au NPs) on the photoluminescence(PL) property of a push-pull conjugated polymer(PBDB-T). We prepared the hybrid system by incorporating poly(3-hexylthiophene)-stabilized Au NPs(P3 HT-Au NPs) into PBDB-T. The enhanced and blueshifted PL was observed in the hybrid system compared to PL in a neat PBDB-T system, indicating that the P3 HT chains attached to the Au NPs suppressed charge-transfer from PBDB-T to the Au NPs and relayed the hot electrons to PBDB-T(the band-filling effect).This photophysical phenomenon limited the auto-dissociation of PBDB-T excitons. Thus, the radiative recombination of the excitons occurred more in our hybrid system than in the neat system.
基金supported by the National Research Foundation of Korea(NRF)grants(NRF-2020R1A2C3004477,RS-2022-00166297)funded by the Ministry of Science and ICT of the Korean government.
文摘Despite recent dramatic improvements in the electronic characteristics of stretchable organic fieldeffect transistors(FETs),their low operational stability remains a bottleneck for their use in practical applications.Here,the operational stability,especially the bias-stress stability,of semiconducting polymer-based FETs under various tensile strains is investigated.Analyses on the structure of stretched semiconducting polymer films and spectroscopic quantification of trapped charges within them reveal the major cause of the strain-dependent bias-stress instability of the FETs.Devices with larger strains exhibit lower stability than those with smaller strains because of the increased water content,which is accompanied by the formation of cracks and nanoscale cavities in the semiconducting polymer film as results of the applied strain.The strain-dependence of bias-stress stability of stretchable OFETs can be eliminated by passivating the devices to avoid penetration of water molecules.This work provides new insights for the development of bias-stable stretchable OFETs.
