空位缺陷对单层2H-MoTe2光电效应的第一性原理研究

MoTe₂由于其类石墨烯的堆叠方式和丰富的相结构而引起科研人员的广泛研究,特别是合适的禁带宽度使其在光电器件领域有着光明的应用前景。基于非平衡格林函数-密度泛函理论,通过第一性原理计算方法,研究了不同原子空位缺陷对单层2H-MoTe₂光电效应的影响。结果表明:不同空位缺陷下2H-MoTe₂器件的光电流函数与唯象理论相符合。光子能量在1.0~2.8 eV时,2Te空位缺陷对单层2H-MoTe₂的光电流有显著提升,特别是在光子能量2.6 eV时获得所有器件的最大光电流。利用能带结构发现不同原子空位缺陷都导致单层2H-MoTe₂的价带向高能级处偏移,而导带向低能级处偏移,减小了带隙,在线性偏振光的照射下有利于电子从价带跃迁到导带形成光电流。同时发现1Te空位缺陷和Mo空位缺陷的单层2H-MoTe₂在远离费米能级处具有相似的能带结构,从而导致在光子能量大于1.6 eV时,1Te空位和Mo空位器件的光电流随光子能量的变化拥有相同的变化趋势。这些计算结果可以用于指导MoTe₂光电器件的设计。     

橙红色磷光铱配合物的合成及其性能

橙红色磷光铱配合物的合成及其性能;电致磷光;铱配合物;苯并噻唑衍生物;光电器件     

二维半导体材料与器件——从传统二维光电材料到石墨炔

近年来,二维半导体材料由于其独特的材料结构和电子输运特性得到了科学界的广泛关注,被应用于光电器件、催化和生物传感器等领域。本文系统概述了传统二维材料以及新兴二维材料石墨炔的发现和发展历程。重点聚焦在二维材料在光探测器领域中的应用,探讨了不同二维材料体系及器件结构对光探测器性能的影响;并详细介绍了新兴二维材料——石墨炔,及其合成和应用。展望了传统二维材料及石墨炔在光电转换器件应用中所面临的机遇和挑战。     

水溶性共轭聚电解质

水溶性共轭聚电解质主要是指含离子型官能团侧链的共轭聚合物,可在水或其它极性有机溶剂中能够溶解。这类化合物把传统共轭聚合物的光电性质和聚电解质的水溶性特点结合在一起,显示出的一些独特性质,可在新一代光电器件制作和化学生物荧光传感器中获得多样的应用。本文总结了近10年来报道的水溶性共轭聚电解质的结构特点和合成方法,以及对不同化学或物理条件下光物理性质的研究,归纳了它们在新一代光电器件制作和荧光传感中的应用,并在此基础上提出了水溶性共轭聚电解质研究中尚待解决的问题,并展望了水溶性共轭聚电解质的应用前景。     

Temperature Induced Aggregation of Organic Semiconductors

One important feature of organic semiconductors is their solution processability, which allows researchers to tune their aggregation states in solution and solid states and to control the processing conditions to reach desirable electronic and optoelectronic properties. Temperature is one of the most important processing parameters of organic semiconductors and has been studied extensively particularly for those conjugated small- and macro- molecules with strong temperature-dependent aggregation properties. This minireview summarizes the temperature-induced aggregation behaviors of organic semiconductors in solution, during solution casting and upon thermal annealing post-treatment of solid-state thin films. The influences of different aggregation states on the optoelectronic properties, in particular the photovoltaic properties, are discussed. The conclusions in this work will provide a rational guide to precisely control the aggregation states of organic semiconductors to fabricate high-performance optoelectronic devices.     

N‐doped cycloparaphenylenes: Tuning electronic properties for applications in thermally activated delayed fluorescence

We theoretically characterize a series of substituted cycloparaphenylene nanohoops to study the effect of incorporating an electron‐withdrawing group into their cyclic structure. We systematically vary the nature, position, and number of nitrogen‐containing acceptor groups in both neutral (pyridine) and charged forms (pyridinium and methylpyridinium) to provide insights into how this functionalization affects the structural, electronic, and optical properties of these systems. We focus also on the singlet‐triplet energy difference, with low values found, which might pave the way to further applications in the field of devices for light‐emitting applications providing a potential class of TADF‐based emitters.     

苯的激光拉曼光谱检测研究

为了对苯的质量分数进行快速准确的检测,采用拉曼光谱法进行检测.对苯的激光拉曼光谱进行了理论分析,进行了标准样品和不同质量分数苯样品的系列拉曼光谱实验.结果表明:苯的拉曼光谱特征峰值与苯的含量成正比,将最强的561.4 nm处的峰值代入线性回归公式,即可得到苯的质量分数,检出限达0.3%.得到一种新的苯质量分数检测方法.     

基于光电反馈的激光混沌并联同步系统研究

提出了基于光电反馈的激光混沌并联同步方案,对可能存在的两种同步——广义同步和完全同步进行了研究,着重讨论了激光器内部参数失配对发射与接收激光器之间以及并联接收激光器之间同步特性的影响.研究结果显示：在一定范围内,同样的内部参数失配下,并联接收激光器之间的同步效果明显优于发射激光器与接收激光器之间的同步效果. 关键词： 半导体激光器 混沌同步 光电反馈 参数失配     

光电负反馈下单向耦合注入垂直腔表面发射激光器的混沌同步特性研究

基于自旋反转模型（SFM）,对光电负反馈下单向耦合注入垂直腔表面发射激光器（VCSEL）的混沌同步特性进行了数值仿真和理论分析.研究结果表明：随着反馈强度的增加,激光器输出功率呈现两个不同的混沌区域.在单一偏振模区域,能实现很好的同步性,但接近两模共存时,同步质量急剧下降;在两模共存区域,偏振模的连续性差,同步质量不理想.两模共存时的同步质量比单一偏振模差的这一特性,与已报道的基于光反馈的情景相反.产生这一特殊现象的原因是光电负反馈诱发了偏振模竞争效应.此外,还发现内部参数的变化对两个混沌区域的选取有较大 关键词： 线性偏振模 光电负反馈 垂直腔表面发射激光器（VCSEL） 混沌同步     

Effect of End‐capping Functional Groups on the Optoelectronic Properties of Oligothiophene Derivatives

Five novel oligothiophene derivatives end‐capped by different functional groups (R=ethoxyl ( EtOP3T ), methylsulfanyl ( MSP3T ), acetyl ( AcP3T ), methylsulfonyl ( MSO₂P3T ) and biphenyl ( BP3T ) groups) were synthesized. They were characterized by Hnuclear magnetic resonanceH (P¹PH NMR), Hmass spectrometryH (MS) and Fourier transform Infra‐red spectra (IR). The relationship between end‐capping functional groups and optoelectronic properties of them was investigated. It was found that the compound with sulfonyl group in the molecular structure ( MSO R ₂ R P3T ) shows the highest oxidation stability (also supported by theoretical calculations) and best thermal stability among the five compounds. The results of scanning electron microscope (SEM) interpret that MSO R ₂ R P3T displays excellent ability of self‐film forming. This reveals that it could be a potential candidate for thin film material. The liquid crystal property of MSO R ₂ R P3T was characterized by polarized optical microscopy analysis (POM) and X‐ray diffraction (XRD). The results of this paper provide useful information for the design of tailored oligothiophene derivatives for devices.