Nonfused ring electron acceptors(NFREAs)are promising candidates for future commercialization of organic solar cells(OSCs)due to their simple synthesis.Still,the power conversion efficiencies(PCEs)of NFREA-based OSCs ...Nonfused ring electron acceptors(NFREAs)are promising candidates for future commercialization of organic solar cells(OSCs)due to their simple synthesis.Still,the power conversion efficiencies(PCEs)of NFREA-based OSCs have large room for improvement.In this work,by merging end group halogenation and side chain engineering,we developed four A-D-A’-D-A type NFREAs,which we refer to as EH-4F,C4-4F,EH-4Cl,and C4-4Cl.Single crystal X-ray diffraction revealed that multiple intermolecular S⋅⋅⋅F interactions between cyclopentadithiophene and 5,6-difluoro-3-(dicyanomethylene)indanone could cause an unfavorable dimer formation,leading to ineffectiveπ-πstackings in EH-4F and C4-4F,whereas no such dimer was found in EH-4Cl and C4-4Cl after replacing with 5,6-dichloro-3-(dicyanomethylene)indanone.Moreover,although the shorter n-butyl side chain resulted in a closer molecular packing in C4-4Cl,EH-4Cl(2-ethylhexyl substitution)with proper crystallinity exhibited enhanced face-on orientation in thin film,which is favorable for vertical charge transport and further reducing charge recombination.As a result,a PCE of 13.0%is obtained for EH-4Cl-based OSC with a fill factor of 0.70.This work highlights the importance of molecular packing and orientation control toward future high-performance A-D-A’-D-A type NFREAs.展开更多
Ferroelectric Sr_(0.6)Ba_(0.4)Nb_(2)O_(6)(SBN)shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied.The presence of such structural vacancy provides the possibili...Ferroelectric Sr_(0.6)Ba_(0.4)Nb_(2)O_(6)(SBN)shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied.The presence of such structural vacancy provides the possibility to further modulate the crystal structure and electrical properties.In this work,alkali ions(Li^(+),Na^(+),K^(+))doped SBN ceramics have been fabricated via solid-solution reaction method.In general,each doping promotes the crystal structure evolves from unfilled toward filled tungsten bronze.However,the different doping ion radius causes the differences in occupying initial structural vacancies,resulting in significantly different electrical properties,Li^(+)doping enhances relaxor characteristic whereas Na+and K^(+)doping lead to normal ferroelectric behavior,accompanying an increase in Curie temperature(TC)from 36℃ of SBN to 40,212,148℃ of Li^(+),Na^(+)and K^(+)doping,respectively.Benefiting from improved relaxor degree and high density,the Li^(+)doped SBN displays a good energy storage performance.Since the ratio of Sr/Ba and(Sr+Ba)/Nb has not been changed,this work presents direct evidence for the effect of structural vacancy on crystal structure and properties,as well as inspiration for further work on unfilled tungsten bronze.展开更多
The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylen...The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylenimine ethoxylated(PEIE)modified organic field-effect transistors(OFETs)is reported.The intrinsic quinoidal characteristic and excellent coplanarity of BDP can lower the lowest unoccupied molecular orbital(LUMO)levels and improve ordered interchain packing of the resulting polymers in solid states,which are favorable for electron-injection and transport.By using PEIE as the interlayer to block the hole injection,unipolar n-type transport characteristics with high electron mobility of 0.58 and 1.01 cm^(2) V^(-1)s^(-1)were achieved by the OFETs based on PBDP-2F and PBDP-2CN,respectively.More importantly,the extracted mobilities are highly reliable with the reliability factor of above 80%.To the best of our knowledge,PBDP-2CN is the very first quinoid-based conjugated polymer with reliable electron mobility exceeding 1 cm^(2) V^(-1)s^(-1).This work represents a significant step in exploring intrinsic quinoidal CPs for application in n-channel OFETs and logic complementary circuits.展开更多
A new polymer donor based on 3,3′-difluoro-2,2′-bithiophene(2F2T) and difluorobenzoxadiazole(ffBX), named 2F2T-ffBX, is designed and synthesized. The organic solar cell(OSC) based on 2F2T-ffBX donor and [6,6]-phenyl...A new polymer donor based on 3,3′-difluoro-2,2′-bithiophene(2F2T) and difluorobenzoxadiazole(ffBX), named 2F2T-ffBX, is designed and synthesized. The organic solar cell(OSC) based on 2F2T-ffBX donor and [6,6]-phenyl-C60-butyl acid methyl ester([60]PCBM) acceptor exhibits a high efficiency of 7.3% with a high open-circuit voltage(Voc) of 1.03 V. When blended with perylenediimide-based acceptor(PDI6), the corresponding OSC shows a higher Voc of 1.19 V with a low energy loss of 0.50 e V but a much lower efficiency of 2.0%. The detailed analyses including charge generation, transport, recombination properties, and morphology were performed to understand the performance of corresponding devices.展开更多
基金National Key Research and Development Program,Grant/Award Number:2019YFA0705900National Natural Science Foundation of China,Grant/Award Numbers:22275058,U20A6002,22109046+1 种基金Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2022B1515120008,2022A1515011417Guangdong Innovative and Entrepreneurial Research Team Program,Grant/Award Number:2019ZT08L075。
文摘Nonfused ring electron acceptors(NFREAs)are promising candidates for future commercialization of organic solar cells(OSCs)due to their simple synthesis.Still,the power conversion efficiencies(PCEs)of NFREA-based OSCs have large room for improvement.In this work,by merging end group halogenation and side chain engineering,we developed four A-D-A’-D-A type NFREAs,which we refer to as EH-4F,C4-4F,EH-4Cl,and C4-4Cl.Single crystal X-ray diffraction revealed that multiple intermolecular S⋅⋅⋅F interactions between cyclopentadithiophene and 5,6-difluoro-3-(dicyanomethylene)indanone could cause an unfavorable dimer formation,leading to ineffectiveπ-πstackings in EH-4F and C4-4F,whereas no such dimer was found in EH-4Cl and C4-4Cl after replacing with 5,6-dichloro-3-(dicyanomethylene)indanone.Moreover,although the shorter n-butyl side chain resulted in a closer molecular packing in C4-4Cl,EH-4Cl(2-ethylhexyl substitution)with proper crystallinity exhibited enhanced face-on orientation in thin film,which is favorable for vertical charge transport and further reducing charge recombination.As a result,a PCE of 13.0%is obtained for EH-4Cl-based OSC with a fill factor of 0.70.This work highlights the importance of molecular packing and orientation control toward future high-performance A-D-A’-D-A type NFREAs.
基金This work was supported by the National Natural Science Foundation of China(No.12174179)the Natural Science Foundation of Jiangsu Province(No.BK20221251)the Dengfeng B project of Nanjing University and the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_0149).
文摘Ferroelectric Sr_(0.6)Ba_(0.4)Nb_(2)O_(6)(SBN)shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied.The presence of such structural vacancy provides the possibility to further modulate the crystal structure and electrical properties.In this work,alkali ions(Li^(+),Na^(+),K^(+))doped SBN ceramics have been fabricated via solid-solution reaction method.In general,each doping promotes the crystal structure evolves from unfilled toward filled tungsten bronze.However,the different doping ion radius causes the differences in occupying initial structural vacancies,resulting in significantly different electrical properties,Li^(+)doping enhances relaxor characteristic whereas Na+and K^(+)doping lead to normal ferroelectric behavior,accompanying an increase in Curie temperature(TC)from 36℃ of SBN to 40,212,148℃ of Li^(+),Na^(+)and K^(+)doping,respectively.Benefiting from improved relaxor degree and high density,the Li^(+)doped SBN displays a good energy storage performance.Since the ratio of Sr/Ba and(Sr+Ba)/Nb has not been changed,this work presents direct evidence for the effect of structural vacancy on crystal structure and properties,as well as inspiration for further work on unfilled tungsten bronze.
基金financial support from the Ministry of Science and Technology of China(2019YFA0705900)National Natural Science Foundation of China(U20A6002,22275058,and 22109046)+2 种基金Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08L075)Guangdong Basic and Applied Basic Research Foundation(2022B1515120008)the Start-up Founding Research and Cultivation Project funded by Ningbo University of Technology(2022KQ65 and 2022TS03)。
基金supported by the Ministry of Science and Technology of China(2017YFA0206600,2019YFA0705900)the National Natural Science Foundation of China(21875072,21774093)+2 种基金the Fundamental Research Funds for Central Universities(South China University of Technology,D2190310)Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08L075)the Open Funds of State Key Laboratory of Fine Chemicals(KF1901)。
文摘The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylenimine ethoxylated(PEIE)modified organic field-effect transistors(OFETs)is reported.The intrinsic quinoidal characteristic and excellent coplanarity of BDP can lower the lowest unoccupied molecular orbital(LUMO)levels and improve ordered interchain packing of the resulting polymers in solid states,which are favorable for electron-injection and transport.By using PEIE as the interlayer to block the hole injection,unipolar n-type transport characteristics with high electron mobility of 0.58 and 1.01 cm^(2) V^(-1)s^(-1)were achieved by the OFETs based on PBDP-2F and PBDP-2CN,respectively.More importantly,the extracted mobilities are highly reliable with the reliability factor of above 80%.To the best of our knowledge,PBDP-2CN is the very first quinoid-based conjugated polymer with reliable electron mobility exceeding 1 cm^(2) V^(-1)s^(-1).This work represents a significant step in exploring intrinsic quinoidal CPs for application in n-channel OFETs and logic complementary circuits.
基金supported by the Ministry of Science and Technology (2017YFA0206600, 2014CB643501)the National Natural Science Foundation of China (21875072, 21520102006, 91633301)the Recruitment Program of Global Youth Experts of China
文摘A new polymer donor based on 3,3′-difluoro-2,2′-bithiophene(2F2T) and difluorobenzoxadiazole(ffBX), named 2F2T-ffBX, is designed and synthesized. The organic solar cell(OSC) based on 2F2T-ffBX donor and [6,6]-phenyl-C60-butyl acid methyl ester([60]PCBM) acceptor exhibits a high efficiency of 7.3% with a high open-circuit voltage(Voc) of 1.03 V. When blended with perylenediimide-based acceptor(PDI6), the corresponding OSC shows a higher Voc of 1.19 V with a low energy loss of 0.50 e V but a much lower efficiency of 2.0%. The detailed analyses including charge generation, transport, recombination properties, and morphology were performed to understand the performance of corresponding devices.
