1 西安理工大学应用化学系, 西安 710054
2 西安理工大学材料物理与化学系, 西安 710048
3 陕西省微生物研究所, 西安 710043
分别以吡嗪和4,4’-联吡啶为共配体, Cd2+、Zn2+与4,4’-偶氮苯二甲酸(H2(4,4’-azo))配位反应得到了两个金属-有机框架(MOFs)。X射线单晶衍射研究结果表明, 其结构中均不含共配体, 与之前报道的 ［Cd(4,4’-azo)(H2O)］n(1)和［Zn(4,4’-azo)(H2O)2］n(2)的晶体结构一致。将共配体变为几何尺寸更长的1,3-二(四吡啶基)丙烷(bpp), 金属离子变为Co2+, 合成了一个共晶［H2(4,4’-azo)(bpp)］n(3), 其为单斜晶系, C2/c空间群, 晶胞参数: a=3.216 8(19) nm, b=0.475 5(3) nm, c=1.873 2(14) nm。用热重分析仪和荧光分光光度计分别研究了三个化合物的热稳定性和两个MOFs的发光性质。1和2都具有优异的热稳定性, 尤其是2的初始失重温度高达247 ℃。由于1是由4,4’-azo双齿配位两个Cd2+形成双核3D网络结构, 而2是4,4’-azo单齿配位Zn2+形成的1D “zig-zag”链, 两者的紫外光谱和荧光光谱不同。2除具有配体固有的荧光发射(359 nm)外, 由于Zn2+与4,4’-azo配位后产生的配体到金属的电荷跃迁(LMCT), 还在420 nm处新增一个增强的荧光发射峰。
4,4’-偶氮苯二甲酸 金属-有机框架 晶体结构 荧光 电荷跃迁 热稳定性 4,4’-azobenzoic acid metal-organic framework crystal structure fluorescence charge transfer thermal stability
Author Affiliations
Abstract
1 College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
2 National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
3 State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China
Terahertz (THz) absorbers for imaging, sensing, and detection are in high demand. However, such devices suffer from high manufacturing costs and limited absorption bandwidths. In this study, we presented a low-cost broadband tunable THz absorber based on one-step laser-induced graphene (LIG). The laser-machining-parameter-dependent morphology and performance of the absorbers were investigated. Coarse tuning of THz absorption was realized by changing the laser power, while it was fine-tuned by changing the scanning speed. The proposed structure can achieve over 90% absorption from 0.5 THz to 2 THz with optimized parameters. The LIG method can help in the development of various THz apparatuses.
terahertz absorber laser-induced graphene Chinese Optics Letters
2022, 20(7): 073701
1 鄂尔多斯源盛光电有限责任公司，内蒙古 鄂尔多斯 017000
2 鄂尔多斯源盛光电有限责任公司，内蒙古 鄂尔多斯 017000)
针对像素电极与公共电极换位(P-ITO and C-ITO Interchanged，PCI) 结构薄膜晶体管液晶显示器(Thin Film Transistor - Liquid Crystal Display，TFT-LCD)产品中出现的一种竖Mura，结合生产工艺的实际情况，本文运用关键尺寸(Critical Dimension，CD)、EPM(Electrical Properties Measurement)、SEM (Scanning Electron Microscope，扫描电子显微镜)等检测设备，进行了大量的实验测试、数据处理和理论分析工作。通过测量Cell Gap、膜厚、CD、Overlay等特性参数，进行产品设计对比、光效模拟和Lens恶化实验，发现该不良与PCI结构的特殊性有关。其产生的根本原因是不良区域内两层ITO之间左右非交叠区域CD差异造成电场分布异常导致液晶偏转角度异常，最终导致屏幕亮暗不均。通过改变ITO对位方式提高两层ITO之间左右非交叠区域的均一性，有效地降低了不良的发生率(从26%下降到01%以内)。
液晶显示器 PCI结构 竖Mura 亮度均一 liquid crystal display P-ITO and C-ITO interchanged structure vertical Mura uniform brightness
