meso-酯类卟啉化合物的合成及光电性能研究

采用Adler-Longo法,设计合成了两种系列共8种具有对称结构的中位四取代酯类卟啉化合物,通过~1H NMR,^(13)C NMR,IR对其分子结构进行了表征,通过紫外-可见光谱法(UV)、荧光光谱法(PL)和循环伏安法(CV)对这些化合物的光电性能进行了研究;结果表明,所合成的中位四取代酯类卟啉化合物结构正确,并均具有较高的荧光量子效率、较低的轨道能隙,是一类较好的光致电材料,在有机半导体材料、有机太阳能电池等方面具有潜在的应用前景。

变光电效应的试验验证及应用前景展望

阐述了变光电效应及该结构体(光交流电池)产生变光电效应的过程及原理,并在得出初步结论的同时做了进一步展望。

Synthesis and optophysical properties of blue-emitting iridium (Ⅲ) complex bearing oxadiazole-based picolinic acid derivative

An iridium （Ⅲ） bis[（4,6-difluorophenyl）pyridinato-N, C^2][6-（6＇-（4＂-（ 5＂-phenyl- 1＂, 3＂, 4＂-oxadiazole-2＂-yl） phenoxy） hexyloxy picolinate） was synthesized and characterized by IH NMR and elementary analysis in order to study the effect of ancillary ligand of the oxadiazole-based picolinic acid derivative on optophysical properties of its iridium complex, and further to obtain an iridium complex with highly-efficient blue emission. The thermal stability, UV absorption and photoluminescent properties of this iridium complex were investigated. Compared with iridium （Ⅲ） bis[（4,6-difluorophenyl）pyridinato-N, C^2]（picolinate） reported as a highly-efficient blue electroluminescent material, this iridium complex bearing an oxadiazole-based picolinic acid derivative presents higher thermal stability, more intense UV absorption at 291 nm and similar photoluminescent spectrum peaked at 469 nm. This indicates that tuning ancillary ligand of picolinic acid with an oxadiazole unit can improve the optophysical properties of its iridium complex.

Organic light-emitting devices based on new rare earth complex Tb(p-ClBA)_3phen

A new rare earth complex Tb（p-CIBA）3phen was synthesized and introduced into organic tight emitting devices （OLEDs） as emitting material. The Tb（p-CIBA）3phen was doped into PVK to improve the filmforming and hole-transporting property. Two kinds of devices were fabricated. The device structure is as the following. Single-layer device： ITO/PVK： Tb （p-CIBA） 3 phen /LiF/Al; double-layer device： ITO/PVK： Tb（p-CIBA）3phen/AIQ/LiF/AI. The performances of both devices were investigated carefully. We found that the emission of PVK was completely restrained,and only the green emission was observed from the electroluminescence. The full width at half maximum （FWHM） was less than 10 nm. The highest EL brighthess of the single-layer device is 25.4 cd/cm^2 at a fixed bias of 18 V,and the highest EL brightness of the double-layer device reaches 234.8 cd/cm^2 at a voltage of 20 V.

Progress in small-molecule luminescent materials for organic light-emitting diodes

Organic light-emitting diodes （OLEDs） have been extensively studied since the first efficient device based on small molecular luminescent materials was reported by Tang. Organic electroluminescent material, one of the centerpieces of OLEDs, has been the focus of studies by many material scientists. To obtain high luminosity and to keep material costs low, a few remarkable design concepts have been developed. Aggregation-induced emission （AIE） materials were invented to overcome the common fluorescence-quenching problem, and cross-dipole stacking of fluorescent molecules was shown to be an effective method to get high solid-state luminescence. To exceed the limit of internal quantum efficiency of conventional fluorescent materials, phosphorescent materials were successfully applied in highly efficient electroluminescent devices. Most recently, delayed flu- orescent materials via reverse-intersystem crossing （RISC） from triplet to singlet and the ＂hot exciton＂ materials based on hy- bridized local and charge-transfer （HLCT） states were developed to he a new generation of low-cost luminescent materials as efficient as phosphorescent materials. In terms of the device-fabrication process, solution-processible small molecular lumi- nescent materials possess the advantages of high purity （vs. polymers） and low procession cost （vs. vacuum deposition）, which are garnering them increasing attention. Herein, we review the progress of the development of small-molecule luminescent materials with different design concepts and features, and also briefly examine future development tendencies of luminescent materials.

Progress in next-generation organic electroluminescent materials:material design beyond exciton statistics

Exciton(or spin)statistics is a physical principle based on the statistics of spin multiplicity.In electroluminescence,injected electrons and holes have randomized spin states,and usually form singlet or triplet excitons in the ratio of 1:3.Exciton statistics determines that the upper limit of internal quantum efficiency is 25%in fluorescent devices,since only singlet exciton can decay radiatively.However,both experimental and theoretical evidence indicate that the actual efficiency can exceed the exciton statistics limit of 25%by utilizing materials with special electronic structure and optimized device structures.These results bring light to break through the exciton statistics limit and develop new-generation fluorescent materials with low cost and high efficiency.Recently,the exciton statistics,which has attracted great attention in the past decade,is being rejuvenated due to the discovery of some fluorescent materials with abnormally high efficiencies.In view of their significance in theoretical research of organic semiconductors and developing new-generation OLED materials,such materials are widely investigated in both academic institutions and industry.Several key issues still require further clarification for this kind of materials,such as the molecular design concepts.Herein,we review the progress of the materials with efficiency exceeding the exciton statistics limit,and the routes to improve exciton utilization efficiency.In the end,we present an innovative pathway to fully harvest the excitons in fluorescent devices,namely,"hot exciton"model and relevant fluorescence material with hybridized local and charge-transfer(HLCT)excited state.

A nano-liter droplet-based microfluidic reactor serves as continuous large-scale production of inorganic perovskite nanocrystals

Lead halide perovskite nanocrystals(NCs)exhibit high photoluminescence quantum yield(PLQY),high defect tolerance,narrow half peak width,and wide luminous gamut,making them the ideal optoelectronic materials in numerous fields.Nonetheless,their production still suffers from the limited productivity at the bench level.In this work,we fabricated CsPbX3(X=Cl,Br,I)NCs within droplet-based micro-reactors,where both the nucleation and growth processes could be precisely controlled inside 130-nL microdroplets.This provides a new paradigm for the large-scale synthesis of perovskite NCs with high PLQY.Compared with other synthetic methods,this method can increase the concentration of reactant precursors by 3±116 times,while lowering the ligand to reactant ratio to 2%±50%of the commonly used hot-injection method.By modulating the reaction temperature and residence time,the structure-function relationship between the morphology of NCs and PL properties was extensively investigated.The microfluidic-based process allows the flexible adjustment in the proportion of PbX2 precursors to achieve the fabrication of perovskite NCs whose luminescence range covers the entire visible spectrum(406±677 nm)within one reaction.Finally,perovskite NCs with different halide ions were encapsulated in polymethyl methacrylate to prepare a colored light-emitting diode strip.

Exceptionally efficient deep blue anthracene-based luminogens:design,synthesis,photophysical,and electroluminescent mechanisms

Achieving high-efficiency deep blue emitter with CIE_(y)<0.06(CIE,Commission Internationale de L’Eclairage)and external quantum efficiency(EQE)>10%has been a long-standing challenge for traditional fluorescent materials in organic light-emitting diodes(OLEDs).Here,we report the rational design and synthesis of two new deep blue luminogens:4-(10-(4’-(9 H-carbazol-9-yl)-2,5-dimethyl-[1,1’-biphe nyl]-4-yl)anthracen-9-yl)benzonitrile(2 M-ph-pCzAnBzt)and 4-(10-(4-(9 H-carbazol-9-yl)-2,5-dimethyl phenyl)anthracen-9-yl)benzonitrile(2 M-pCzAnBzt).In particular,2 M-ph-pCzAnBzt produces saturated deep blue emissions in a non-doped electroluminescent device with an exceptionally high EQE of 10.44% and CIE_(x,y)(0.151,0.057).The unprecedented electroluminescent efficiency is attributed to the combined effects of higher-order reversed intersystem crossing and triplet-triplet up-conversion,which are supported by analysis of theoretical calculation,triplet sensitization experiments,as well as nanosecond transient absorption spectroscopy.This research offers a new approach to resolve the shortage of high efficiency deep blue fluorescent emitters.