用于10Gbit/s传输的对接集成DFB-LD/EA-MD光源

报道了用于10Gbit/s传输的DFB激光器和EA调制器对接集成器件的设计、制作和器件特性.工作主要集中于两个方面:提高激光器和调制器间的光学耦合;通过减小调制器电容提高调制带宽.集成器件显示出了良好的静态和高频特性:阈值电流典型值为15mA,最小值为8mA;100mA激光器偏置电流下,输出功率大于10mW;对消光比、电学回波损耗和调制带宽进行了测试,3dB带宽的测量值超过10GHz.     

GaAs基RTD与MSM光电集成

报道了GaAs基共振隧穿二极管(RTD)与金属-半导体-金属光电探测器(MSM PD)单片集成的两种光电集成电路,并在室温条件下分别测试了RTD器件、MSM器件和集成电路的电学特性.测试表明:RTD器件的峰谷电流比为4;由于改进了在半绝缘GaAs衬底上制作MSM的方法,5V偏压下的电流由原来的2μA增加到了18μA,基本实现了两种电路的逻辑功能.     

Special Issue onEI北大核心CSCD

“Low-dimensional Integrated Opto-Electronic Materials and Devices”1.Summary and scope Low-dimensional(LD)materials and devices are backbones of new generation optoelectronic circuitries and systems with higher integration capacity and better performance.Entering post-Moore era,silicon(Si)-based electronic transistor technology is confronted with increasing short-channel and energy consumption bottlenecks.In response of this challenge,novel LD optoelectronic materials with exotic photo-and electro-physical effects are on augmenting demand to both expand the functionality and promote the efficiency of integrated information devices.     

二维钙钛矿材料制备技术研究进展

钙钛矿因具有可调性结构、低缺陷密度、高载流子迁移率以及带隙可调等优异的物理化学特性而被广泛地应用于太阳能电池和光电探测器等光电器件领域。二维钙钛矿材料由于维度和厚度尺寸减小,引起量子限域效应,使得电子-空穴相互作用增强,激子结合能增大。因此,二维钙钛矿材料与其块体材料相比表现出了更优异的光电特性,并且稳定性增强,迅速成为二维材料领域的研究热点。结合近几年国内外研究现状,综述了剥离法、液相法和气相法等3种二维钙钛矿材料的制备方法,分析了各种方法的优缺点,并对其未来的发展进行了展望。指出二维钙钛矿材料的研究需要重点关注以下两个方面:1）开发一种简单可行的大规模生产大尺寸、高质量、环境友好以及高稳定性的二维钙钛矿材料的制备方法仍然是该领域研究的重点,3种制备方法中气相法是非常有可能实现大规模生产大尺寸、高质量二维钙钛矿材料的有效途径,但是急需解决的问题是降低设备成本以及通过改进工艺条件来提高二维钙钛矿材料的生长速度;2）二维钙钛矿材料在太阳能电池、光电探测器、LED等光电器件领域已经表现出很好的应用前景,但是光电器件的工作原理以及如何精确调控材料形貌与发光性能等这些基础研究仍然需要更深入的探讨,也是未来关注的重点。     

基于石墨烯透明导电薄膜的OLED研究进展

作为透明导电薄膜材料,石墨烯（Graphene）因具有十分优异的力学、光学和电学特性,在未来的柔性光电器件如触摸屏、有机发光二极管（OLED）和有机光伏电池（OPV）中表现出极大的发展潜力和广阔的应用前景。然而,受面电阻大、功函数不匹配以及表面粗糙度等关键因素的影响,基于本征石墨烯薄膜的光电器件的性能较低、稳定性较差,严重阻碍了石墨烯薄膜在柔性光电器件中的发展和应用。主要针对近年来石墨烯透明导电薄膜在OLED中应用的研究进展进行概述,并总结得出可以通过石墨烯薄膜掺杂、表面功函数修饰、清洁无损转移,以及器件结构优化等方法,进一步提高器件的性能。最后分析了石墨烯透明导电薄膜在OLED器件应用中的关键技术瓶颈,并对石墨烯透明导电薄膜在OLED中的应用前景进行了展望。     

Size‐Controlled Soft‐Template Synthesis of Carbon Nanodots toward Versatile Photoactive Materials

Size‐controlled soft‐template synthesis of carbon nanodots (CNDs) as novel photoactive materials is reported. The size of the CNDs can be controlled by regulating the amount of an emulsifier. As the size increases, the CNDs exhibit blue‐shifted photoluminescence (PL) or so‐called an inverse PL shift. Using time‐correlated single photon counting, ultraviolet photoelectron spectroscopy, and low‐temperature PL measurements, it is revealed that the CNDs are composed of sp² clusters with certain energy gaps and their oleylamine ligands act as auxochromes to reduce the energy gaps. This insight can provide a plausible explanation on the origin of the inverse PL shift which has been debatable over a past decade. To explore the potential of the CNDs as photoactive materials, several prototypes of CND‐based optoelectronic devices, including multicolored light‐emitting diodes and air‐stable organic solar cells, are demonstrated. This study could shed light on future applications of the CNDs and further expedite the development of other related fields.     

Synthesis of Poly(arylene vinylene)s Containing Carbazole,Triphenylamine, and Phenothiazine Rings in the Backbone by Cascade Suzuki-Heck Reactions

Three new conjugated poly(arylene vinylene) structures containing triphenylamine, carbazole, or phenothiazine as aromatic units in the main chain and connected by vinyl segments have been synthesized by a cascade Suzuki-Heck reactions. The best reaction yields were obtained by coupling of the dibromoarylamines with vinyl segments via Suzuki-Heck reaction cascade using Pd(OAc)₂ as catalyst and triethylamine as solvent. The polymers were obtained as fully or partially soluble materials in chlorinated or aprotic polar solvents. They were characterized by ¹H-NMR, FT-IR, UV-Vis, and photoluminescence spectroscopy. Cyclic voltammetry characteristics were studied in solution and as solid thin films deposited on the electrode surface.     

强短脉冲激光冲击薄板高速变形的实验研究

强短脉冲激光冲击材料成形是一种高应变率的过程。很多已有测试手段由于响应带宽不够而无法进行有效测量。常用的任意面速度干涉仪(VISAR)价格昂贵、测试方法复杂,且存在条纹缺失。采用一种简单的光电测试系统探测出铝薄板在强短脉冲激光冲击下的高速变形过程。通过标定输出电压与变形量的关系,分析出薄板被冲击中心点的位移和速度,与文献仿真结果规律一致,计算出在8 J激光能量冲击时间内平均变形速度为8.49×104m/s。并由阻尼振动和弹性形变叠加的模型拟合出激光冲击薄板的形变过程,根据拟合系数计算出薄板的振动速度和塑性变形值,为分析和控制激光冲击变形工艺提供了依据。     

利用光电反馈抑制钛宝石激光器低频段的强度噪声

对前置光电负反馈抑制钛宝石激光器强度噪声方法的特性进行了理论分析,表明注入噪声不同时对应的最佳反馈增益不同。利用前置光电负反馈方法,在实验上实现了全固态连续单频可调谐钛宝石激光器低频段的强度噪声抑制,通过调节反馈增益,使激光器的强度噪声抑制程度最大。在分析频率为1.125 MHz处,强度噪声由原来的8.7 dB降低到了1.4 dB,抑制程度达7.3 dB。调节反馈增益和相位延时,可以获得不同分析频率的强度噪声的降低。     

LiF层作为空穴阻挡层的绿色OLED的光电性能研究

采用真空热蒸镀方法,制备了四种Delta掺杂结构OLED器件,其结构为：ITO/m-MTDATA（50nm）/LiF（xnm）/NPB（10nm）/Alq（5nm）/C545T（0.05nm）/Alq（55nm）/LiF（1nm）/Al,都获得了性能稳定的绿色OLED器件。从实验结果分析可知：绿色OLED器件的电流-电压（I-V）特性曲线、亮度-电压（L-V）曲线、亮度-电流（L-I）曲线及效率等光电性能随着LiF厚度的变化而随之改变。从其中总结规律,对OLED器件制作工艺有一定的指导作用。