检索结果-南通市图书馆

Design high-performance narrowband emitters for blue light-emitting diodes through manipulating resonance structure of aromatic heterocycles

引用

Science China Chemistry 2025年

作者： Yue Yu Lei Xu Wenle Tan Yuyu Pan Jiyin Xiao Bohan Wang Guangjun Tian yuguang ma Lei Ying Institute of Polymer Optoelectronic materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials State Key Laboratory of Luminescent Materials and Devices South China University of Technology School of Petrochemical Engineering Shenyang University of Technology Key Laboratory for Microstructural material Physics of Hebei Province School of Science Yanshan University

Narrowband light-emitting materials play critical roles in improving the color gamut and energy consumption of electroluminescence. Herein we demonstrated that by regulating the ground state resonance structure form of emitters with polycyclic aromatic heterocycles, the high-energy vibration of the C–C bond can be effectively suppressed, resulting in narrow emission like classical cyanine dyes. The designed compounds consist of twist and planar conformation, while having differences in the orientation of the positioning electron-donating(nitrogen) and electron-accepting(carbonyl) groups in the polycyclic aromatic hydrocarbon skeleton. The resulting compound Ac-Ph-Ac with a dominated zwitterionic resonance structure exhibits a relatively wide electroluminescent profile with the full width at half maximum(FWHM) of 42 nm and moderate device performance. In contrast, the “soliton transition” of 2AcPh based on the cyanine limit character effectively suppresses C–C stretching vibration in the polycyclic aromatic heterocycle skeleton, leading to a narrow electroluminescent profile with FWHM of 30 nm(0.16 eV)associated with an impressively high external quantum efficiency of 28.52%, which is among the highest efficiencies of so far reported non-sensitized organic light-emitting diodes.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Violating the Aufbau principle: an efficient way to improve the stability of luminescent radicals

引用

Science China Chemistry 2019年第12期62卷 1551-1552页

作者： yuguang ma Institute of Polymer Optoelectronic materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology

The Aufbau principle,also known as“building-up”principle,is a method of explaining the arrangements of electrons within atoms of different chemical *** principle was initially introduced by Danish physicist Niels Bohr and the basic statements include“Electrons will fill orbitals in increasing order of energy,and each orbital can contain a maximum of two electrons,and these must have opposite spins”[1].The principle is not perfect,and there are a few exceptions,but it is a very useful tool for learning about atomic and molecular structure.

关键词： structure. stability arrangement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thickness Dependence of Doping Level in Conducting Polymer Films:the Optical Contrast Optimization in Electrochromism as a Case Study

引用

Chinese Journal of Chemistry 2022年第5期40卷 597-602页

作者： Jianqiao Wang Huanhuan Zhang yuguang ma State Key Laboratory of Luminescent materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of TechnologyNo.381 Wushan RoadTianhe DistinctGuangzhouGuangdong510640 China

Doping plays an essential role in the properties of conducting *** thickness not only has a direct influence on their photoelectric properties,but also affects the doping ability,which may lead to the decline of capacitance and electrochromic properties caused by incomplete ***,it is essential to study the quantitative relationship between doping level and film thickness in ***,empirical formula between doping level and thickness was obtained by studying the spectroelectrochemistry behaviors of two different electrochromic materials,poly(N,N'-bis(3,5-(2-thienyl)-phenyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-perylenetetracarboxylic diimide)(poly(Th-Cl-PBI))and poly(3,4-ethylenedioxythiophene)(PEDOT).The doping level is verified to be correlated to the reciprocal of the 3^(rd)power of film *** results fit these formulas very well,giving correlation coefficient R^(2)higher than *** optical contrast prediction of these two electrochromic materials is also used to verify this relationship *** the first time,we quantitatively connect these two important parameters of conducting polymers,doping level and thickness.

关键词： Doping Electrochemistry Polymers Electrochromism Thickness dependence

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

引用

Science China Chemistry 2014年第3期57卷 335-345页

作者： YAO Liang YANG Bing ma yuguang State Key Laboratory of Supramolecular Structure and materials Jilin University State Key Laboratory of Luminescent materials and Devices South China University of Technology

Exciton(or spin)statistics is a physical principle based on the statistics of spin *** electroluminescence,injected electrons and holes have randomized spin states,and usually form singlet or triplet excitons in the ratio of 1:*** statistics determines that the upper limit of internal quantum efficiency is 25%in fluorescent devices,since only singlet exciton can decay ***,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 *** results bring light to break through the exciton statistics limit and develop new-generation fluorescent materials with low cost and high ***,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 *** 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 *** key issues still require further clarification for this kind of materials,such as the molecular design ***,we review the progress of the materials with efficiency exceeding the exciton statistics limit,and the routes to improve exciton utilization *** 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.

关键词： organic light-emitting device(OLED) exciton statistics reverse intersystem crossing(RISC) hybridized local and charge-transfer(HLCT) hot exciton

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

Science China Chemistry 2015年第6期58卷 907-915页

作者： Tiancheng Yu Linlin Liu Zengqi Xie yuguang ma State Key Laboratory of Luminescent materials and Devices Institute of Polymer Optoelectronic materials and Devices South China University of Technology

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.

关键词： organic light-emitting diodes small molecular luminescent materials fluorescence phosphorescence delayed fluores-cence hybridized local and charge-transfer state

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Progress on the optoelectronic functional organic crystals

引用

Science China Chemistry 2007年第4期50卷 433-452页

作者： WANG Huan XIE ZengQi ma yuguang Shen JiaCong Key Laboratory for Supramolecular Structure and materials of Ministry of Education Jilin UniversityChangchun 130012China

Organic crystals constructed by pi-conjugated molecules have been paid great attention to in the field of organic optoelectronic materials. The superiorities of these organic crystal materials, such as high thermal stability, highly ordered structure, and high carrier mobility over the amorphous thin film ma-terials, make them attractive candidates for optoelectronic devices. Single crystal with definite struc-ture provides a model to investigate the basic interactions between the molecules (supramolecular interaction), and the relationship between molecular stacking modes and optoelectronic performance (luminescence and carrier mobility). Through modulating molecular arrangement in organic crystal, the luminescence efficiency of organic crystal has exceeded 80% and carrier mobility has been up to the level of 10 cm2·V?1·s?1. Amplified stimulated emission phenomena have been observed in many crys-tals. In this paper, we will emphatically introduce the progress in optoelectronic functional organic crystals and some correlative principle.

关键词： organic crystals luminescence mobility laser field effect

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Uniform composition film of hydrophilic colloidal gold nanoparticles and hydrophobic carbazole functionalized fluorene trimers for enhanced fluorescence and stability

引用

Chinese Science Bulletin 2013年第22期58卷 2741-2746页

作者： LIU LinLin XIE ZengQi ma yuguang State Key Laboratory of Luminescent materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of Technology State Key Laboratory of Supramolecular Structure and materials Jilin University

Compositing gold nanoparticles into conjugated molecules have been developed to be one of the most important approaches to increase stability, since degradation of conjugated materials is now one of the biggest bottle-necks to be conquered before industrialization application. Big-size colloidal gold nanoparticles with strong surface plasma resonance are designed to composite with conjugated molecules, in order to realize effective fluorescence enhancement and stabilization. The uniform composition film of hydrophilic colloidal gold nanoparticles (particle diameter of 30 nm) and hydrophobic carbazole functionalized fluorene trimers has been obtained by direct mixing of their aqueous and THF solutions, which is determined by AFM. By the comparison of composition based on fluorene trimers with similar structures, we have found that peripheral carbazole group and molecular size of fluorene trimers play an important role in the balance of incompatible solubility, which is regarded as increasing solubility of fluorene trimers in mixed solvent, connecting AuNP and peripheral carbazole groups, and restraining aggregate of gold nanoparticle. This allows facile hydrophilic gold nanoparticle to disperse uniformly in hydrophobic-conjugated host. Our investigations show that fluorescence intensity of composition film is enhanced by 4 folds, and heat treatment (200°C for 4h) for the composition film does not induce the degradation of conjugated backbone without the appearance of low-energy emission band, demonstrating the prominent potency of gold nanoparticles in enhanced fluorescence and stability of conjugated molecules and polymers.

关键词：金纳米粒子亲水性胶体荧光增强均匀分散三聚体稳定性薄膜咔唑

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Exploration of structure and mechanism of insoluble gels formed in microwave-assisted Suzuki coupling for poly(9,9-dihexylfluorene)s

引用

Science China Chemistry 2012年第5期55卷 844-849页

作者： ZHANG WenSi LU Ping WANG ZhiMing ma yuguang State Key Laboratory of Supramolecular Structure and materials College of ChemistryJilin UniversityChangchun 130012China

A series of poly(9,9-dihexylfluorene)s (PDHFs) have been synthesized via microwave-assisted Suzuki and Yamamoto coupling reactions. Compared with the conventional oil-bath heating (48 h, Mw 20100 g/mol by Suzuki reaction and Mw 24000 g/mol by Yamamoto reaction), microwave-assisted polymerization can yield PDHFs with higher molecular weights (Mw 37200 g/mol by Suzuki reaction and Mw 43400 g/mol by Yamamoto reaction) in shorter time (14 and 60 min). However, sometimes formation of insoluble gels was observed together with PDHF in Suzuki coupling reaction. PDHF and insoluble gels were analyzed by XPS, elemental analysis, FTIR, TGA and DSC. Experimental results demonstrated that H2O might take part in the Suzuki coupling reaction under microwave condition, which could make the cross-linking reaction occur and form gels.

关键词： microwave Suzuki Yamamoto PDHF gels

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Photoluminescence and Electroluminescence of Poly p-Phenyl Phenol Prepared by Enzymatic Catalyzed Polymerization

引用

Chinese Physics Letters 1994年第6期11卷 387-389页

作者： ma yuguang TANG Jianguo ma Lin LIU Shiyong SHEN Jiacong The National Laboratory of Integrated Optic Electronics The National Laboratory of Enzyme Engineering The Key Laboratory for Molecular Spectra and Structure Jilin UniversityChangchun 130023

The photoluminescence(PL)peak of poly p-phenyl phenol(PPP)is at about 370-420nm excited by the light at *** absorption band edges and photon emitting peaks of the polymer are found the conjugated lengths dependent on molecular weight of *** the transient luminescence measurement the lifetime of PL decay is determined to be 2.0ns which is supposed an evidence of polaron excitation *** electroluminescence is observed with aluminum/PPP/indium-tinoxide cell.

关键词： Phenol Polymerization excited

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Precursor synthesis strategy for polycyclic aromatic conjugated polymers on the application of supercapacitors

引用

Science China Chemistry 2018年第2期61卷 192-199页

作者： Zhenhua Zhang Weitao ma Biao Xu Xuehong Zhou Cong Wang Zengqi Xie Linlin Liu yuguang ma Institute of Polymer Optoelectronic materials and Devices State Key Laboratory of Luminescent Materials and DevicesSouth China University of Technology

Polycyclic aromatics (PCAs) possess excellent photoelectric properties, but the construction of such compounds has been a quite challenging subject of study, mainly due to very low solubility. Herein we report a precursor synthesis strategy for polycyclic aromatic conjugated polymers. A soluble precursor polymer, that containing fusible "double U-shaped aromatic"(DUA) and perylenetetracarboxydiimide (PDI) units, was firstly synthesized by Suzuki coupling. The stereo aromatic units in polymer backbone were found to be converted into polycyclic aromatic units, i.e. hexa-peri-hexabenzocoronene (HBC), by chemical or electrochemical oxidation, which resulted in a formation of insoluble polycyclic aromatic conjugated polymers. The electrochemical oxidations that occurred at the interface of electrode and solution exhibited higher cyclization reactivity and leads to the formation of high quality films on the electrode surface. Characterization by Raman and UV-visible (UV-Vis) spectroscopy validated the successful formation of this HBC structure. Some potential applications of such thin films are being explored, and here we focus on the characteristics of supercapacitors based on their excellent electrochemical properties.

关键词： polycyclic aromatics conjugated polymer electrochemical deposition supercapacitor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：