The current trend for fabricating OLEDs is solution processing in the scope for low-cost manufacturing, but most small organic molecules must be deposited in vacuum to fabricate devices due to their poor solubility. I...The current trend for fabricating OLEDs is solution processing in the scope for low-cost manufacturing, but most small organic molecules must be deposited in vacuum to fabricate devices due to their poor solubility. In this paper, a new soluble anthracene derivative 2-tert-butyl-9,10-bis(9,9-dipropylfluorenyl)anthracene(TBPFA) was designed and synthesized. The compound exhibited pure-blue-light emitting(λmax=443 nm in dilute dichloromethane, λmax=450 nm in solid film) and high fluorescence quantum efficiency. The none-doped and doped single-layer devices were prepared successfully by spin coating process with TBPFA as blue-light emitting material and blue-light emitting host material respectively. In the doped device, TBPFA can transport energies to TBPe which is a good blue-light emitting material efficiently.展开更多
Organic light-emitting diode(OLED)is an electroluminescent technology that relies on charge-carrier dynamics and is a potential light source for variable environmental conditions.Here,by exploiting a self-developed lo...Organic light-emitting diode(OLED)is an electroluminescent technology that relies on charge-carrier dynamics and is a potential light source for variable environmental conditions.Here,by exploiting a self-developed low-temperature testing system,we investigated the characteristics of hole/electron transport,electro-optic conversion efficiency,and operation lifetime of OLEDs at low-temperature ranging from-40℃to 0℃and room temperature(25℃).Compared to devices operating at room temperature,the carrier transport capability is significantly decreased with reducing temperature,and especially the mobility of the hole-transporting material(HTM)and electron-transporting material(ETM)at-40℃decreases from 1.16×10-6 cm2/V·s and 2.60×10-4 cm2/V·s to 6.91×10-9 cm2/V·s and 1.44×10-5 cm2/V·s,respectively.Indeed,the temperature affects differently on the mobilities of HTM and ETM,which favors unbalanced charge-carrier transport and recombination in OLEDs,thereby leading to the maximum current efficiency decreased from 6.46 cd·A-1 at 25℃to 2.74 cd·A-1 at-40℃.In addition,blue fluorescent OLED at-20℃has an above 56%lifetime improvement(time to 80%of the initial luminance)over the reference device at room temperature,which is attributed to efficiently dissipating heat generated inside the device by the low-temperature environment.展开更多
Light has been sought and explored by human since ancient times.As the most important form of light,fluorescence is significant to applications in bioimaging and optoelectronic devices.However,fluorescence quenching p...Light has been sought and explored by human since ancient times.As the most important form of light,fluorescence is significant to applications in bioimaging and optoelectronic devices.However,fluorescence quenching problem constitutes a serious bottleneck in materials creation.Inspired from the core–shell structure in nature,we report an effective strategy to overcome this long-standing problem by utilizing a molecular core–shell structure.With an emissive core and multifunctional shell fragments,these compounds show aggregation-induced delayed fluorescence(AIDF)properties by restricting singlet oxygen(^(1)O_(2))generation and suppressing the triplet–triplet annihilation(TTA).Protected by the functional shell,the aggregation-induced emission luminogens(AIEgens)exhibit strong emission with high photoluminescent quantum yield and exciton utilization.Furthermore,because the shell materials can form exciplex with electron-transport materials,the fully solution-processed organic light-emitting diodes(OLEDs)based on these core–shell materials show low turnon voltages,excellent device performance with current efficiency of 61.4 cd A–1 and power efficiency of 42.8 lm W–1,which is a record-breaking efficiency based on all-solution processed organic multilayer systems among the AIE-OLEDs so far.This simple visualization strategy based on molecular core–shell structure provides a promising platform for AIEgens used in the fully wet-processed optoelectronic field.展开更多
A series of Sc,Y,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Ho,Er,Tm and Yb complexes with oxybenzoquinoline ligands(BQ) was synthesized by the reactions of 10-hydroxybenzo[h]quinoline with cyclopentadienides or tris(trimethylsilyl)amides ...A series of Sc,Y,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Ho,Er,Tm and Yb complexes with oxybenzoquinoline ligands(BQ) was synthesized by the reactions of 10-hydroxybenzo[h]quinoline with cyclopentadienides or tris(trimethylsilyl)amides of rare earth metals.The structure,as well as the photo-and electroluminescent(PL,EL) properties of these complexes in solutions and solid state were studied.In solutions,complexes of sodium and lanthanides exhibit double peaked ligand-centered PL of enol and keto forms of BQ with a quantum yield of 1%-8%.In the solid state the complexes of Sm,Eu,Ho,Nd,Er,and Yb along with the ligand-centered PL also exhibit a moderate-intensity metal-centered PL which is characteristic of the corresponding Ln^(3+) ions.Sc(BQ)_(3) complex shows bright green EL which has intensity comparable to the best results observed for scandium complexes with other organic ligands.展开更多
This paper summarizes the mechanism and routes for excitation of triplet emitters in dopant emission based phosphorescent organic light-emitting diodes (PhOLEDs),providing a comprehensive overview of recent progress i...This paper summarizes the mechanism and routes for excitation of triplet emitters in dopant emission based phosphorescent organic light-emitting diodes (PhOLEDs),providing a comprehensive overview of recent progress in molecular hosts for triplet emitters in PhOLEDs.Particularly,based on the nature of different hosts,e.g.,hole transporting,electron transporting or bipolar materials,in which the dopant emitters can be hosted to generate phosphorescence,the respective device performances are summarized and compared.Highlights are given to the relationships among the molecular structure,thermal stability,triplet energy,carrier mobility,molecular orbital energy level and their corresponding device performances.展开更多
Organic semiconductor materials with low reorganization energy have various applications such as in organic light-emitting diodes (OLEDs),organic field-effect transistor (OFETs) and organic solar cells (OSCs).In this ...Organic semiconductor materials with low reorganization energy have various applications such as in organic light-emitting diodes (OLEDs),organic field-effect transistor (OFETs) and organic solar cells (OSCs).In this work,we have designed a new class of gridspiroarenes (GS-SFX and GS-SITF) with #-shaped structures,which have novel crisscross geometrical structures compared to widely used spirocyclic arenes-SFX and SITF.The structure electronic properties,adiabatic ionization potentials (IPa),adiabatic electron affinities (EAa) and reorganization energies (λ) of GS-SFX and GS-SITF have been calculated using density functional theory (DFT) method.The calculated HOMO and LUMO spatial distributions suggest that GS-SFX and GS-SITF have better transport properties.The noncovalent interaction analysis shows the weak intramolecular interactions between their arms.The results indicate that the reorganization energies of GS-SFX and GS-SITF are significantly reduced compared to the dimer structures-DSFX and DSITF.Furthermore,the GS-SITF1 which is one of the isomers of GS-SITF exhibits the lowest values for λ(h)(0.067 eV) and λ(e)(0.153 eV).Therefore,we believe the predicted structure,electronic property,and reorganization energy are good indicator for transport materials.This work has systematically studied the effect of gridization,which provides insights to design organic semiconductor materials with excellent charge transport properties.展开更多
Through-space charge transfer(TSCT)polymers are an attractive class of luminescent polymers with spatial donor/acceptor architecture and thermally activated delayed fluorescence effect,different from conventional lumi...Through-space charge transfer(TSCT)polymers are an attractive class of luminescent polymers with spatial donor/acceptor architecture and thermally activated delayed fluorescence effect,different from conventional luminescent polymers with conjugated donor-acceptor structure and through-bond charge transfer emission.Their emission comes from the intramolecular charge transfer by through-space pathway because the donor and acceptor segments are spatially proximate to each other in each repeating unit but are physically separated by nonconjugated polymer backbone.In this review,recent advances in TSCT polymers with linear,bottlebrush,and dendritic architectures are presented,with the focus on their molecular design,photophysical behavior,and device performance.We hope that this review shall provide a useful insight of new luminescent polymers with TSCT effect for use in solution-processed organic light-emitting diodes.展开更多
Organic photovoltaic(OPV) cells and organic light-emitting diodes(OLEDs) are energy harvesting and generation devices that have attracted great attention these years because of their low costs, thin film structures,fl...Organic photovoltaic(OPV) cells and organic light-emitting diodes(OLEDs) are energy harvesting and generation devices that have attracted great attention these years because of their low costs, thin film structures,flexibility and environment-friendly manufacturing processes. For such thin film devices, photon management methods that increase the light absorption of OPV cells and the light extraction from OLEDs are highly desirable.Here, we report the experimental efforts to fabricate geometrically tunable and spontaneously formed nano-wrinkle structures with large areas, and the theoretical results on photon management with the nano-wrinkles.展开更多
文摘The current trend for fabricating OLEDs is solution processing in the scope for low-cost manufacturing, but most small organic molecules must be deposited in vacuum to fabricate devices due to their poor solubility. In this paper, a new soluble anthracene derivative 2-tert-butyl-9,10-bis(9,9-dipropylfluorenyl)anthracene(TBPFA) was designed and synthesized. The compound exhibited pure-blue-light emitting(λmax=443 nm in dilute dichloromethane, λmax=450 nm in solid film) and high fluorescence quantum efficiency. The none-doped and doped single-layer devices were prepared successfully by spin coating process with TBPFA as blue-light emitting material and blue-light emitting host material respectively. In the doped device, TBPFA can transport energies to TBPe which is a good blue-light emitting material efficiently.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61775130 and 11974236)the Science and Technology Commission of Shanghai Municipality Program,China(Grant Nos.19DZ2281000 and 17DZ2281000)the Research Innovation Program for College Graduates of Jiangsu Province,China(Grant Nos.KYCX202545 and KYCX202549)。
文摘Organic light-emitting diode(OLED)is an electroluminescent technology that relies on charge-carrier dynamics and is a potential light source for variable environmental conditions.Here,by exploiting a self-developed low-temperature testing system,we investigated the characteristics of hole/electron transport,electro-optic conversion efficiency,and operation lifetime of OLEDs at low-temperature ranging from-40℃to 0℃and room temperature(25℃).Compared to devices operating at room temperature,the carrier transport capability is significantly decreased with reducing temperature,and especially the mobility of the hole-transporting material(HTM)and electron-transporting material(ETM)at-40℃decreases from 1.16×10-6 cm2/V·s and 2.60×10-4 cm2/V·s to 6.91×10-9 cm2/V·s and 1.44×10-5 cm2/V·s,respectively.Indeed,the temperature affects differently on the mobilities of HTM and ETM,which favors unbalanced charge-carrier transport and recombination in OLEDs,thereby leading to the maximum current efficiency decreased from 6.46 cd·A-1 at 25℃to 2.74 cd·A-1 at-40℃.In addition,blue fluorescent OLED at-20℃has an above 56%lifetime improvement(time to 80%of the initial luminance)over the reference device at room temperature,which is attributed to efficiently dissipating heat generated inside the device by the low-temperature environment.
基金National Natural Science Foundation of China,Grant/Award Numbers:21875036,22135004Open Fund of theKeyLab of Organic Optoelec-tronics&Molecular EngineeringInnovation and Technology Commission,Grant/Award Number:ITC-CNERC14SC01。
文摘Light has been sought and explored by human since ancient times.As the most important form of light,fluorescence is significant to applications in bioimaging and optoelectronic devices.However,fluorescence quenching problem constitutes a serious bottleneck in materials creation.Inspired from the core–shell structure in nature,we report an effective strategy to overcome this long-standing problem by utilizing a molecular core–shell structure.With an emissive core and multifunctional shell fragments,these compounds show aggregation-induced delayed fluorescence(AIDF)properties by restricting singlet oxygen(^(1)O_(2))generation and suppressing the triplet–triplet annihilation(TTA).Protected by the functional shell,the aggregation-induced emission luminogens(AIEgens)exhibit strong emission with high photoluminescent quantum yield and exciton utilization.Furthermore,because the shell materials can form exciplex with electron-transport materials,the fully solution-processed organic light-emitting diodes(OLEDs)based on these core–shell materials show low turnon voltages,excellent device performance with current efficiency of 61.4 cd A–1 and power efficiency of 42.8 lm W–1,which is a record-breaking efficiency based on all-solution processed organic multilayer systems among the AIE-OLEDs so far.This simple visualization strategy based on molecular core–shell structure provides a promising platform for AIEgens used in the fully wet-processed optoelectronic field.
基金supported by the Russian Science Foundation (2073-10115)。
文摘A series of Sc,Y,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Ho,Er,Tm and Yb complexes with oxybenzoquinoline ligands(BQ) was synthesized by the reactions of 10-hydroxybenzo[h]quinoline with cyclopentadienides or tris(trimethylsilyl)amides of rare earth metals.The structure,as well as the photo-and electroluminescent(PL,EL) properties of these complexes in solutions and solid state were studied.In solutions,complexes of sodium and lanthanides exhibit double peaked ligand-centered PL of enol and keto forms of BQ with a quantum yield of 1%-8%.In the solid state the complexes of Sm,Eu,Ho,Nd,Er,and Yb along with the ligand-centered PL also exhibit a moderate-intensity metal-centered PL which is characteristic of the corresponding Ln^(3+) ions.Sc(BQ)_(3) complex shows bright green EL which has intensity comparable to the best results observed for scandium complexes with other organic ligands.
基金supported by the National Natural Science Foundation of China (20974046)funding from the Nanjing University of Posts and Telecommunications (207162)+2 种基金Natural Science Foundation of Jiangsu High Education (08KJB430011)New Century Excellent Talents funding from Ministry of Education in China (NCET-08-0697)National Basic Research Program of China (973 Program) (2009CB930600)
文摘This paper summarizes the mechanism and routes for excitation of triplet emitters in dopant emission based phosphorescent organic light-emitting diodes (PhOLEDs),providing a comprehensive overview of recent progress in molecular hosts for triplet emitters in PhOLEDs.Particularly,based on the nature of different hosts,e.g.,hole transporting,electron transporting or bipolar materials,in which the dopant emitters can be hosted to generate phosphorescence,the respective device performances are summarized and compared.Highlights are given to the relationships among the molecular structure,thermal stability,triplet energy,carrier mobility,molecular orbital energy level and their corresponding device performances.
基金This work was supported by the National Natural Science Foundation of China (Nos. 21503114, 21774061, 61605090, 91833306)Synergetic Innovation Centre for Organic Electronics and In formation Displays, Nanji ng Un iversity of Posts a nd Telecommunications Scientific Foundation NUPTSF (NY215056, NY21417& NY215172, 2016XSG03)the Six Peak Talents Foundation of Jiangsu Province (XCL-CXTD-009), and the High Performanee Computing Center of Nanjing Tech University.
文摘Organic semiconductor materials with low reorganization energy have various applications such as in organic light-emitting diodes (OLEDs),organic field-effect transistor (OFETs) and organic solar cells (OSCs).In this work,we have designed a new class of gridspiroarenes (GS-SFX and GS-SITF) with #-shaped structures,which have novel crisscross geometrical structures compared to widely used spirocyclic arenes-SFX and SITF.The structure electronic properties,adiabatic ionization potentials (IPa),adiabatic electron affinities (EAa) and reorganization energies (λ) of GS-SFX and GS-SITF have been calculated using density functional theory (DFT) method.The calculated HOMO and LUMO spatial distributions suggest that GS-SFX and GS-SITF have better transport properties.The noncovalent interaction analysis shows the weak intramolecular interactions between their arms.The results indicate that the reorganization energies of GS-SFX and GS-SITF are significantly reduced compared to the dimer structures-DSFX and DSITF.Furthermore,the GS-SITF1 which is one of the isomers of GS-SITF exhibits the lowest values for λ(h)(0.067 eV) and λ(e)(0.153 eV).Therefore,we believe the predicted structure,electronic property,and reorganization energy are good indicator for transport materials.This work has systematically studied the effect of gridization,which provides insights to design organic semiconductor materials with excellent charge transport properties.
基金National Natural Science Foundation of China,Grant/Award Numbers:51833009,52073282,91833306973 Project,Grant/Award Number:2015CB655000Youth Innovation Promotion Association of Chinese Academy of Sciences,Grant/Award Number:2015180。
文摘Through-space charge transfer(TSCT)polymers are an attractive class of luminescent polymers with spatial donor/acceptor architecture and thermally activated delayed fluorescence effect,different from conventional luminescent polymers with conjugated donor-acceptor structure and through-bond charge transfer emission.Their emission comes from the intramolecular charge transfer by through-space pathway because the donor and acceptor segments are spatially proximate to each other in each repeating unit but are physically separated by nonconjugated polymer backbone.In this review,recent advances in TSCT polymers with linear,bottlebrush,and dendritic architectures are presented,with the focus on their molecular design,photophysical behavior,and device performance.We hope that this review shall provide a useful insight of new luminescent polymers with TSCT effect for use in solution-processed organic light-emitting diodes.
基金the National High Technology Research and Development Program(863)of China(No.2011AA050518)the National Natural Science Foundation of China(No.61275168) the SJTU-UM Joint Research Fund
文摘Organic photovoltaic(OPV) cells and organic light-emitting diodes(OLEDs) are energy harvesting and generation devices that have attracted great attention these years because of their low costs, thin film structures,flexibility and environment-friendly manufacturing processes. For such thin film devices, photon management methods that increase the light absorption of OPV cells and the light extraction from OLEDs are highly desirable.Here, we report the experimental efforts to fabricate geometrically tunable and spontaneously formed nano-wrinkle structures with large areas, and the theoretical results on photon management with the nano-wrinkles.
