In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting m...In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.展开更多
Two electron-deficient azaacenes including di-and tetra-cyanodiazafluorene(DCAF and TCAF)with the advantages of deep lowest unoccupied molecular orbital(LUMO),green-synthesis,low-cost,simply purification method,excell...Two electron-deficient azaacenes including di-and tetra-cyanodiazafluorene(DCAF and TCAF)with the advantages of deep lowest unoccupied molecular orbital(LUMO),green-synthesis,low-cost,simply purification method,excellent yields have been obtained,characterized and used as electron injection materials(EIMs)in three groups of electroluminescence devices.Device B with TCAF as EIM exhibited the best performance including turn-on voltage of 5.0 V,stronger maximum luminance intensity of 31,549 cd/m2,higher luminance efficiency of 62.34 cd/A and larger power efficiency of 21.74 lm/W which are 0.53,6.7,9.3 and 15.3 times than that of device A with DCAF as EIMs,respectively.The enhanced interfacial electron injection ability of TCAF than that of DCAF is supported by its better electron mobility in electron-only device,deeper LUMO(-4.52 eV),and stronger electronic affinity.Best external quantum efficiency of 16.56%was achieved with optimized thicknesses of TCAF as EIM and TPBi as electron transporting layer.As a new comer of acceptor family,TCAF would push forward organic electronics with more fascinating and significant applications.展开更多
A hybrid structure consisting of boron-doped porous carbon spheres and graphene （BPCS-G） has been designed and synthesized toward solving the polysulfide- shuttle problem, which is the most critical issue of current...A hybrid structure consisting of boron-doped porous carbon spheres and graphene （BPCS-G） has been designed and synthesized toward solving the polysulfide- shuttle problem, which is the most critical issue of current Li-S batteries. The proposed hybrid structure showing high surface area （870 m^2.g^-1） and high B-dopant content （6.51 wt.%） simultaneously offers both physical confinement and chemical absorption of polysulfides. On one hand, the abundant-pore structure ensures high sulfur loading, facilitates fast charge transfer, and restrains polysulfide migration during cycling. On the other hand, our density functional theory calculations demonstrate that the B dopant is capable of chemically binding polysulfides. As a consequence of such dual polysulfide confinement, the BPCS-G/S cathode prepared with 70 wt.% sulfur loading presents a high reversible capacity of 1,174 mAh.g^-1 at 0.02 C, a high rate capacity of 396 mAh·g^-1 at 5 G and good cyclability over 500 cycles with only 0.05% capacity decay per cycle. The present work provides an efficient and cost-effective platform for the scalable synthesis of high-performance carbon-based materials for advanced Li-S batteries.展开更多
Diketopyrrolopyrrole(DPP)derivatived photosensitizers(PSs)with near infrared(NIR)absorption and good photophysical properties have drawn tremendous attention in cancer phototherapy.However,current DPP derivatives pres...Diketopyrrolopyrrole(DPP)derivatived photosensitizers(PSs)with near infrared(NIR)absorption and good photophysical properties have drawn tremendous attention in cancer phototherapy.However,current DPP derivatives present unsatisfactory quantum yield of singlet oxygen(1O2)due to the large energy gap between the excited singlet and triplet states.To tackle this challenge,herein the DPP core is functionalized with triphenylphosphine-Au(I)group(Th DPP-Au),leading to a high1O2 quantum yield of 0.65.Theoretical calculation attributes the enhancement to spin-orbit coupling and population of the triplet excition upon photoexcitation.The hydrophilic Th DPP-Au nanoparticals(NPs)are prepared via nano-reprecipitation,which displays homogeneous size and excellent light absorption ability(ε=4.382×104 M-1cm-1).And the Th DPP-Au NPs exhibit low dark toxicity and high phototoxicity,which can effectively kill tumor cells via 1O2 induced mitochondrial apoptotic pathway upon irradiation.Furthermore,in vivo experiments demonstrate that Th DPP-Au NPs can selective accumulation in tumor and present excellent synergistic photodynamic/photothermal therapy guided by fluorescence and photothermal dual imaging.展开更多
Will ports become less important in a post-industrial period dominated by service industries?This paper examines the impact and the spillover effects of ports on city economies.The results show that ports contribute t...Will ports become less important in a post-industrial period dominated by service industries?This paper examines the impact and the spillover effects of ports on city economies.The results show that ports contribute to city economies primarily through producer and consumer services.To be specific,ports can drive the development of port-related producer services,and port spillover effects from other cities have a broader impact on producer services;the port contributes to the development of wholesale and retail trades in the local city but the boost to consumer services comes mainly from spillover effects from other ports.This paper concludes that ports are still shaping economic geography by influencing the service sector,and inter-city coordination mechanisms are suggested because of the spillover effects.展开更多
基金financially supported by the National Key Research and Development Program of China (2018YFB0406704)the National Natural Science Foundation of China (61974066, 61725502, 61634001)+3 种基金the Major Research Plan of the National Natural Science Foundation of China (91733302)the fund for Talented of Nanjing Tech University (201983)the Major Program of Natural Science Research of Jiangsu Higher Education Institutions of China (18KJA510002)the Synergetic Innovation Center for Organic Electronics and Information Displays。
文摘In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.
基金the National Natural Science Foundation of China(Nos.21975126,51673095,21875104,21875191,21603104)the Natural Science Foundation of Jiangsu Province(Nos.BK20171470,BK20160991,BK20150064,BK20130912)+1 种基金973 Program(No.2015CB932200)Ministry of Education and Synergetic Innovation Center for Organic Electronics and Information Displays for financial support
文摘Two electron-deficient azaacenes including di-and tetra-cyanodiazafluorene(DCAF and TCAF)with the advantages of deep lowest unoccupied molecular orbital(LUMO),green-synthesis,low-cost,simply purification method,excellent yields have been obtained,characterized and used as electron injection materials(EIMs)in three groups of electroluminescence devices.Device B with TCAF as EIM exhibited the best performance including turn-on voltage of 5.0 V,stronger maximum luminance intensity of 31,549 cd/m2,higher luminance efficiency of 62.34 cd/A and larger power efficiency of 21.74 lm/W which are 0.53,6.7,9.3 and 15.3 times than that of device A with DCAF as EIMs,respectively.The enhanced interfacial electron injection ability of TCAF than that of DCAF is supported by its better electron mobility in electron-only device,deeper LUMO(-4.52 eV),and stronger electronic affinity.Best external quantum efficiency of 16.56%was achieved with optimized thicknesses of TCAF as EIM and TPBi as electron transporting layer.As a new comer of acceptor family,TCAF would push forward organic electronics with more fascinating and significant applications.
文摘A hybrid structure consisting of boron-doped porous carbon spheres and graphene （BPCS-G） has been designed and synthesized toward solving the polysulfide- shuttle problem, which is the most critical issue of current Li-S batteries. The proposed hybrid structure showing high surface area （870 m^2.g^-1） and high B-dopant content （6.51 wt.%） simultaneously offers both physical confinement and chemical absorption of polysulfides. On one hand, the abundant-pore structure ensures high sulfur loading, facilitates fast charge transfer, and restrains polysulfide migration during cycling. On the other hand, our density functional theory calculations demonstrate that the B dopant is capable of chemically binding polysulfides. As a consequence of such dual polysulfide confinement, the BPCS-G/S cathode prepared with 70 wt.% sulfur loading presents a high reversible capacity of 1,174 mAh.g^-1 at 0.02 C, a high rate capacity of 396 mAh·g^-1 at 5 G and good cyclability over 500 cycles with only 0.05% capacity decay per cycle. The present work provides an efficient and cost-effective platform for the scalable synthesis of high-performance carbon-based materials for advanced Li-S batteries.
基金supported by the National Natural Science of Foundation of China(61525402,61775095,21704043)Jiangsu Provincial Key Research and Development Plan(BE2017741)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20170990,17KJB150020)the Six talent peak innovation team in Jiangsu Province(TD-SWYY-009)
文摘Diketopyrrolopyrrole(DPP)derivatived photosensitizers(PSs)with near infrared(NIR)absorption and good photophysical properties have drawn tremendous attention in cancer phototherapy.However,current DPP derivatives present unsatisfactory quantum yield of singlet oxygen(1O2)due to the large energy gap between the excited singlet and triplet states.To tackle this challenge,herein the DPP core is functionalized with triphenylphosphine-Au(I)group(Th DPP-Au),leading to a high1O2 quantum yield of 0.65.Theoretical calculation attributes the enhancement to spin-orbit coupling and population of the triplet excition upon photoexcitation.The hydrophilic Th DPP-Au nanoparticals(NPs)are prepared via nano-reprecipitation,which displays homogeneous size and excellent light absorption ability(ε=4.382×104 M-1cm-1).And the Th DPP-Au NPs exhibit low dark toxicity and high phototoxicity,which can effectively kill tumor cells via 1O2 induced mitochondrial apoptotic pathway upon irradiation.Furthermore,in vivo experiments demonstrate that Th DPP-Au NPs can selective accumulation in tumor and present excellent synergistic photodynamic/photothermal therapy guided by fluorescence and photothermal dual imaging.
基金Shanghai Philosophy and Social Science Fund(No.2018BJB008)Liberal Arts and Social Sciences Foundation of Ministry of Education in China(No.21YJC790060).
文摘Will ports become less important in a post-industrial period dominated by service industries?This paper examines the impact and the spillover effects of ports on city economies.The results show that ports contribute to city economies primarily through producer and consumer services.To be specific,ports can drive the development of port-related producer services,and port spillover effects from other cities have a broader impact on producer services;the port contributes to the development of wholesale and retail trades in the local city but the boost to consumer services comes mainly from spillover effects from other ports.This paper concludes that ports are still shaping economic geography by influencing the service sector,and inter-city coordination mechanisms are suggested because of the spillover effects.
