We fabricate a series of samples and OLEDs with organic multilayer quantum well structure, which consist of alternate PBD and Alqy Both PBD and Alq3 are electron-transporting materials, and PBD is used as potential ba...We fabricate a series of samples and OLEDs with organic multilayer quantum well structure, which consist of alternate PBD and Alqy Both PBD and Alq3 are electron-transporting materials, and PBD is used as potential barrier layer, while Alq3 is used as potential well layer and emitting layer. Compared with double-layer structure, the luminescent characteristics of organic samples and diodes with quantum well structure are investigated and the quantum well structure helps the energy transfer between well layer and barrier layer. The quantum well structure makes carriers disperse in the different well layers and then increases the number of excitons to enhance the efficiency of the recombination.展开更多
Abstract: Organic multiple quantum well(OMQ) structures consisting of alternating layers of tris(8 - quinolinolato)aluminum( ff) (Alq3) and 2 - (4 - biphenylyl) -5 - (4 - ter - butylphenyl) -(1,3,3- oxadiazole) (PBD) ...Abstract: Organic multiple quantum well(OMQ) structures consisting of alternating layers of tris(8 - quinolinolato)aluminum( ff) (Alq3) and 2 - (4 - biphenylyl) -5 - (4 - ter - butylphenyl) -(1,3,3- oxadiazole) (PBD) have been fabricated by organic molecular beam deposition (OMBD). The individual layer thickness in the multilayer samples was varied from 6 nm to 20 nm. The multiple quantum well structures were determined by low angle X - ray diffraction, optical absorption and photolumi-nescence(PL). The PL spectra narrow and the emission energy has been observed to shift to higher energy compared with that in the monolayer structure, suggesting a quantum size effect.展开更多
Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular ass...Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular assemblies could be a potentially viable approach toward artificial photosynthesis.Although self-assembled organic materials are known to carry out water splitting reactions,developing self-assembled organic materials for photocatalytic overall water splitting still remains a critical challenge.Herein,we first demonstrate that crystalline organic nanosheets assembled from linear oligo(phenylene butadiynylene)(OPB)are able to catalyze overall water splitting under visible light irradiation.Further investigations reveal that the photocatalytic activity of self-assembled organic structures is closely related to the crystalline structure along with the corresponding electronic structure.Structural disorders in OPB nanosheets and extrinsic factors such as adsorbed water molecules will induce the formation of electron traps which can make the OPB nanosheets thermodynamically unfavorable for photocatalytic overall water splitting.The deactivation mechanism unveiled in this study provides crucial insights into the assembling of artificial organic materials for future solar-to-chemical energy conversion.展开更多
基金This work was Supported by "973" National Key Basic ResearchFoundation of China (No. 2003CB314707)National Natural Sci-ence Foundation of China (No. 60576016 ,10374001, and No.10434030).
文摘We fabricate a series of samples and OLEDs with organic multilayer quantum well structure, which consist of alternate PBD and Alqy Both PBD and Alq3 are electron-transporting materials, and PBD is used as potential barrier layer, while Alq3 is used as potential well layer and emitting layer. Compared with double-layer structure, the luminescent characteristics of organic samples and diodes with quantum well structure are investigated and the quantum well structure helps the energy transfer between well layer and barrier layer. The quantum well structure makes carriers disperse in the different well layers and then increases the number of excitons to enhance the efficiency of the recombination.
文摘Abstract: Organic multiple quantum well(OMQ) structures consisting of alternating layers of tris(8 - quinolinolato)aluminum( ff) (Alq3) and 2 - (4 - biphenylyl) -5 - (4 - ter - butylphenyl) -(1,3,3- oxadiazole) (PBD) have been fabricated by organic molecular beam deposition (OMBD). The individual layer thickness in the multilayer samples was varied from 6 nm to 20 nm. The multiple quantum well structures were determined by low angle X - ray diffraction, optical absorption and photolumi-nescence(PL). The PL spectra narrow and the emission energy has been observed to shift to higher energy compared with that in the monolayer structure, suggesting a quantum size effect.
基金the National Key R&D Program of China(2017YFA0207301,2016YFA0200602,and 2018YFA0208702)the National Natural Science Foundation of China(21875235,21573211,and 21633007)+2 种基金the Anhui Initiative in Quantum Information Technologies(AHY090200)the China Postdoctoral Science Foundation(BX20200317)the Fundamental Research Funds for the Central Universities。
文摘Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular assemblies could be a potentially viable approach toward artificial photosynthesis.Although self-assembled organic materials are known to carry out water splitting reactions,developing self-assembled organic materials for photocatalytic overall water splitting still remains a critical challenge.Herein,we first demonstrate that crystalline organic nanosheets assembled from linear oligo(phenylene butadiynylene)(OPB)are able to catalyze overall water splitting under visible light irradiation.Further investigations reveal that the photocatalytic activity of self-assembled organic structures is closely related to the crystalline structure along with the corresponding electronic structure.Structural disorders in OPB nanosheets and extrinsic factors such as adsorbed water molecules will induce the formation of electron traps which can make the OPB nanosheets thermodynamically unfavorable for photocatalytic overall water splitting.The deactivation mechanism unveiled in this study provides crucial insights into the assembling of artificial organic materials for future solar-to-chemical energy conversion.
