基于石墨烯的半导体光电器件研究进展

石墨烯自从被发现以来,由于其零带隙、低电导率、常温下的高电子迁移率及量子霍尔效应和独特的光吸收等优良特性,引发了世界各国科研人员的重视,研究人员对其物理性质及应用的研究越来越多并且进展迅速．本文以光纤通信用光电器件中的探测器、调制器为主,综述了石墨烯在光电探测器、调制器以及超快锁模激光器和用于发光二级管、触摸屏透明导电薄膜等方面的应用．     

Progress in the realisation of an autonomous environmental monitoring device for ammonia

Progress in the development of a micro-fluidic system for colorimetric monitoring of ammonia in drinking and wastewater is described. The ultimate goal is to have a miniaturised instrument that can produce accurate, reliable measurements, is easy to operate, has minimal power consumption, and can operate autonomously for a year. In this study, the indophenol reaction is incorporated into a simple, reliable analytical micro-fluidic system. Absorbance measurements for the blue ammonia-indophenol complex formed in the micro-fluidic system are shown. A key issue is the limiting stability of hypochlorite, a reagent used in the assay. The effects of hypochlorite concentration and impurities on the stability of hypochlorite are investigated and discussed. Decomposition is shown to be very dependent on the presence of heavy-metal impurities. With low levels of these catalytic metals and careful storage, hypochlorite has been shown to be stable for over a year.     

Synthesis of a novel rigid molecule family for the investigation of electron and energy transfer

Three new rigid bridging ligands for metal complexation (7=bmb, 8=bqb and 11=btb) were prepared from a rigid triptycene spacer connected to two bipyridine ligands using a Horner–Emmons type reaction. The triptycene spacer is substituted by methoxy groups in the case of bmb and in the case of bqb by a benzoquinone substituent. The corresponding metal complexes (ruthenium and/or osmium) were synthesised and the different luminescence behaviour was tested. They show great potential for the investigation of intramolecular electron and energy transfer reactions. The dinuclear metal complex Ru---bqb---Os is an interesting system in which the bridging ligand bqb acts as a redox switch, able to tune the conductivity for energy or electrons across the bridge.     

卟啉超分子化合物在分子器件中的应用

分子电子器件已成为近年来的一个研究热点，卟啉类化合物因为光敏性好、性能稳定、易于修饰等优点成为分子器件研究的理想模型化合物。本文着重介绍了它在分子器件中的最新应用进展。     

Freestanding Carbon Nanotube Film for Flexible Straplike Lithium/Sulfur Batteries

Flexible lithium/sulfur (Li/S) batteries are promising to meet the emerging power demand for flexible electronic devices. The key challenge for a flexible Li/S battery is to design a cathode with excellent electrochemical performance and mechanical flexibility. In this work, a flexible strap-like Li/S battery based on a S@carbon nanotube/Pt@carbon nanotube hybrid film cathode was designed. It delivers a specific capacity of 1145 mAh g⁻¹ at the first cycle and retains a specific capacity of 822 mAh g⁻¹ after 100 cycles. Moreover, the flexible Li/S battery retains stabile specific capacity and Coulombic efficiency even under severe bending conditions. As a demonstration of practical applications, an LED array is shown stably powered by the flexible Li/S battery under flattened and bent states. We also use the strap-like flexible Li/S battery as a real strap for a watch, which at the same time provides a reliable power supply to the watch.     

卟啉类化合物分子光电器件研究进展

分子电子器件是未来分子电路的微电子元件,已成为有机功能纳米材料研究的热点。 卟啉类化合物的π共轭体系表现出的独特光电性能和良好的热稳定性,使其作为光电器件、模拟生物酶、分子识别和传感材料在材料化学、医学、生物化学和分析化学等领域展现出良好的应用前景,由于卟啉分子平面结构的易修饰性,常用卟啉化合物组装单元来构建功能化的卟啉光电器件。 本文综述了卟啉类化合物的特点及其在光电器件中的应用进展。     

Isometric crystallization of stretched poly(e-caprolactone) sheets for medical applications

Low melting temperature thermoplastic sheets based on poly(e-caprolactone) (PCL) can be formed directly on the patient and are used as immobilization device (mask) in the radiation therapy. The immobilization mask is allowed to harden in isometric conditions on the body at room temperature. A new method for isometric crystallization kinetics of thermoplastic polymer sheets is developed using a tensile-strength instrument. The isometric crystallization method allows investigating the shrinkage force on time of crystallization of stretched samples of thermoplastic polymer sheets or immobilization medical devices. The dependence of the shrinkage force on time is described by Avrami equation and the kinetics parameters of isometric crystallization are calculated. This revised version was published online in July 2006 with corrections to the Cover Date.     

Alcohol‐Processable Organic Amorphous Electrolytes as an Effective Electron‐Injection Layer for Organic Light‐Emitting Diodes

A new series of monoammonium‐based organic electrolytes with the tetrafluoroborate (BF₄^?) counteranion have been synthesized. Replacing the pendant ethyl groups in the fluorenyl unit with 4‐ethoxyphenyl groups dramatically improves both solubility and morphological stability. The characterization of the alcohol‐processable amorphous ionic compounds as an electron‐injection layer in organic light‐emitting diodes (OLEDs) reveals that the organic electrolyte that comprises a rigid linear‐conjugated unit provides better device performance, with respect to its counterpart containing a branched bulky moiety. The capability of these compounds to facilitate electron injection from air‐stable aluminum metal is preliminarily discussed on the basis of the investigations of the electron‐only devices and photovoltaic experiments.     

Functional Polyoxometalate Thin Films via Electrostatic Layer-by-Layer Self-Assembly

Polyoxometalates (POMs) comprise a structurally diverse class of inorganic transition metal oxygen clusters which—owing to their unique electronic properties—hold promise for a host of technological applications such as electrochromic windows, sensors, or heterogeneous catalysts, prototypic examples of which will be briefly exemplified. The integration of POMs into functional architectures and devices, however, necessitates the development of general methods that allow positioning these clusters in well-defined supramolecular architectures, thin films, or mesophases. This short review highlights recent advances in the preparation of composite multilayers fabricated by electrostatic layer-by-layer self-assembly (ELSA) of POMs and a variety of water-soluble cationic species, including transition metal complexes, cationic surfactants, polycations and bipolar pyridine.