排序方式: 共有45条查询结果,搜索用时 15 毫秒
1.
在聚2,7-(9,9-二辛基)芴(PFO)和30%的2-(对联苯基)-5-(对叔丁基苯基)-1,3,4-噁二唑(PBD)主体材料中掺杂短磷光寿命的meso-四(对正葵酰氧基苯基)卟啉铂(TDPPPt),制成聚合物基发光器件。 器件结构为:ITO/PEDOT∶PSS/PVK/PFO+30%PBD∶TDPPPt/Ca/Al(ITO:氧化铟锡;PEDOT:聚3,4-乙撑二氧噻吩;PSS:聚苯乙烯磺酸盐;PVK:聚乙烯基咔唑)。 当客体掺杂浓度≥3%时,器件给出饱和的红色发射。 当驱动电压从7 V升高至14 V时,器件发光色度保持不变,CIE(国际发光照明委员会)色坐标稳定在(0.66,0.28)左右。 器件的最大亮度和电流效率分别为1.390 cd/m2和1.34 cd/A。 在电流密度100×10-3和150×10-3 A/cm2时,电流效率分别为1.18和0.99 cd/A,器件在高电流密度下具有良好的稳定性。 相似文献
2.
The effect of band mixing and non-parabolicity on quantum well gain and spontaneous emission is studied using k.p theory. Spectra of gain and spontaneous emission are strongly modified but the relation of maximum gain versus nominal current density is not strongly affected. 相似文献
3.
Dr. Wei-Hua Deng Prof. Qiao-Hong Li Jie Chen Chuan-Zhe Wang Dr. Zhi-Hua Fu Dr. Xiao-Liang Ye Prof. Guan-E Wang Prof. Gang Xu 《Angewandte Chemie (International ed. in English)》2023,62(31):e202305977
The electronic conductivity (EC) of metal–organic frameworks (MOFs) is sensitive to strongly oxidizing guest molecules. Water is a relatively mild species, however, the effect of H2O on the EC of MOFs is rarely reported. We explored the effect of H2O on the EC in the MOFs (NH2)2-MIL-125 and its derivatives with experimental and theoretical investigations. Unexpectedly, a large EC increase of 107 on H2SO4@(NH2)2-MIL-125 by H2O was observed. Brønsted acid–base pairs formed with the −NH2 groups, and H2SO4 played an important role in promoting the charge transfer from H2O to the MOF. Based on H2SO4@(NH2)2-MIL-125, a high-performance chemiresistive humidity sensor was developed with the highest sensitivity, broadest detection range, and lowest limit of detection amongst all reported sensing materials to date. This work not only demonstrated that H2O can remarkably influence the EC of MOFs, but it also revealed that post-modification of the structure of MOFs could enhance the influence of the guest molecule on their EC to design high-performance sensing materials. 相似文献
4.
Xiao-Yang Chen Hongliang Chen J. Fraser Stoddart 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(1):e202211387
The tetracationic cyclophane, cyclobis(paraquat-p-phenylene), also known as the little blue box, constitutes a modular receptor that has facilitated the discovery of many host–guest complexes and mechanically interlocked molecules during the past 35 years. Its versatility in binding small π-donors in its tetracationic state, as well as forming trisradical tricationic complexes with viologen radical cations in its doubly reduced bisradical dicationic state, renders it valuable for the construction of various stimuli-responsive materials. Since the first reports in 1988, the little blue box has been featured in over 500 publications in the literature. All this research activity would not have been possible without the seminal contributions carried out by Siegfried Hünig, who not only pioneered the syntheses of viologen-containing cyclophanes, but also revealed their rich redox chemistry in addition to their ability to undergo intramolecular π-dimerization. This Review describes how his pioneering research led to the design and synthesis of the little blue box, and how this redox-active host evolved into the key component of molecular shuttles, switches, and machines. 相似文献
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The integration of multiscale and multicomponent of molecules and nanoparticles into thin films for applications requires the abilities of controlled their processing and assembly,which has been an great challenge because of the difficulty in manipulating the various materials such as small molecules,complexes,polymers,and inorganic nanomaterials through synergetic combinations of chemical or physical fabrications.Eletropolymerization is of great significance to fabricate polymeric film materials straight on the conductive substrates with tunable morphologies and thicknesses.However,unlimited electrochemical reactions(polymerization)have been usually leading to disadvantageous in ill-defined structure and highly doped state.Thanks to finding of exceptional electrochemical reaction(oligomerization)of N-alkylcarbazole,electrochemical layer by layer assembly has emerged as a promising strategy for a wide library of applications.The capability of this strategy can manipulate various molecules and nanoparticles into the scale and component controllable thin films.Unlike other electropolymerizable precursors such as aniline and thiophene,the resulting di-N-alkylcarbazole is transparent in the visible light region and thus does not impair the intrinsic properties of the components in the film.This account highlights of the typical findings in investigating both single-and multi-components thin films as a forum for discussing new opportunities in exploiting novel designs and applications of optical thin films. 相似文献
7.
Jiaxin Hong Minghui Liu Youxing Liu Shengcong Shang Xinyu Wang Changsheng Du Wenqiang Gao Chunyu Hua Helin Xu Zewen You Prof. Yunqi Liu Prof. Jianyi Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(9):e202317876
Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid-liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA-TPA (PyTTA: 4,4′,4′′,4′′′-(1,3,6,8-Tetrakis(4-aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light-stimulated synaptic plasticity properties such as short-term plasticity (STP), long-term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions. 相似文献
8.
Dr. Min Chen Prof. Wee-Liat Ong Prof. Boyu Peng Dr. Xuyun Guo Dr. Jie Ren Prof. Ye Zhu Prof. Hanying Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(7):e202314685
Semicrystalline polymer dielectrics (SPDs) are highly sought-after state-of-the-art dielectric materials. As the disorder in SPDs degrades their electrical properties, homogeneously ordered SPDs are desired. However, complex crystallization behaviors of polymers make such homogeneity elusive. Polymer lamellar single crystals (PLSCs), the most regularly-ordered form of SPDs possible under mild crystallizing conditions, are ideal platforms for understanding and developing high-performance dielectric materials. Here, a typical and widely used SPD, polyethylene (PE) is selected as the model material. We successfully obtained, large, uniform, and high-quality PE PLSCs and devised a non-destructive strategy to construct PE PLSC-based vertical capacitors. These nanometer-thick capacitors exhibit exceptional dielectric properties, with a high breakdown strength of 6.95 MV/cm and a low dielectric constant of 2.14±0.07, that outperform the properties of any existing neat PE. This work provides novel insights into exploring the performance possibility of ordered SPDs and reveals the PLSCs as potential high-performance dielectric materials. 相似文献
9.
M. J. Pontes M. J. D. Dos Santos I. Abe H. J. Kalinowski M. T. M. R. Giraldi 《Fiber and Integrated Optics》2000,19(1):57-65
We report the results from the characterization and optimization of a stable erbium-doped fiber ring laser that uses two optical filters. The observed laser performance and the measured longitudinal mode patterns are presented. The influence of the combination of the two optical filters on the mode suppression is evaluated. We obtained the matched condition for operation of the optical filters that most improved the laser performance. An estimate of the relative intensity noise due to the introduction of the laser in a communication system is also presented. As a consequence of the mode suppression, a sharp laser linewidth narrowing is con firmed. 相似文献
10.
Fast Integrated Electro-Optical Switch and Beam Deflector Based on Nematic Liquid Crystal Waveguides
L. Sirleto L. Petti P. Mormile G. C. Righini G. Abbate 《Fiber and Integrated Optics》2002,21(6):435-449
In this paper, the design, the realization, and the experimental characterization of an integrated electro-optical switch and a beam deflector, both based on planar nematic liquid crystal (NLC) waveguides, are reported.
In order to test such devices, a particular waveguide structure consisting of a three-stage device, having a thin nematic LC film as the middle stage and two glass waveguides as the other stages, has been designed and realized. The electro-optical behavior and the response time have been studied for different configurations for both TE and TM polarized light. By a proper choice of the material parameters and because of the presence of an additional constant bias voltage, we got response time in the microsecond range. The experimental results obtained are very promising in the frame of integrated electro-optical devices, even if the effect underlying the results is not yet understood and probably needs some deeper research into liquid crystal physics and surface interactions. 相似文献
In order to test such devices, a particular waveguide structure consisting of a three-stage device, having a thin nematic LC film as the middle stage and two glass waveguides as the other stages, has been designed and realized. The electro-optical behavior and the response time have been studied for different configurations for both TE and TM polarized light. By a proper choice of the material parameters and because of the presence of an additional constant bias voltage, we got response time in the microsecond range. The experimental results obtained are very promising in the frame of integrated electro-optical devices, even if the effect underlying the results is not yet understood and probably needs some deeper research into liquid crystal physics and surface interactions. 相似文献