氧化镓纳米材料的制备及其在光电探测方面的应用研究进展

近年来,半导体的纳米材料凭借其奇特的介观物理特性,成为当前研究的热点,特别是纳米金属氧化物。氧化镓纳米材料具备优异的光电、气敏、耐压且低损耗等特性,为材料学、电子学和化学等多个研究领域带来了新的机遇。本文概述了氧化镓纳米结构的制备方法,并展望了其在光电探测方面的应用。     

光电跟踪系统计算机辅助控制实现

建立了基于数值微分的目标运动状态滤波预测模型,用s-函数实现了卡尔曼滤波预测算法。利用目标位置拟合方法给出角位置信息,并以此为观测信息通过卡尔曼滤波预测出当前角位置和角速度信息,将其引入跟踪控制系统中以克服脱靶量滞后问题,同时也实现了系统的等效复合控制。仿真结果表明,基于数值微分的模型适用于角度跟踪,滤波预测具有较好的鲁棒性。通过对两个不同等效正弦输入的验证,可知角位置合成精度对共轴跟踪影响较大,在脱靶量和跟踪架角位置采样匹配对应时,跟踪仿真精度较高,而对等效复合控制跟踪误差影响较小,输入信号角频率增大时误差增大。     

8-羟基喹啉锂的光电性能和取代基效应的密度泛函理论

采用密度泛函理论(DFT)较为系统地研究了给、吸电子取代基对8-羟基喹啉锂(Liq)光电性能的影响。研究结果表明:不同取代基与母体形成不同的共轭,取代基—CN、—OCH3很好地参与了整个π体系共轭,对体系性质影响较大;吸电子基—CF3、—CN、—Cl在5-位取代都使Liq的最高占据轨道(HOMO)、最低空轨道(LUMO)能级降低;给电子基—CH3、—CH3CH2CH2、—OCH3在5-位取代都使Liq的LUMO、HOMO升高,带隙减小,给电性越强,影响越显著;—CN在5-位取代,显著增加了Liq的电子亲和势,降低了电子重组能,使电子更易于注入和传输。与Liq及其它衍生物相比,5-CN-Liq是一种更好的电子注入和传输材料。     

Laser-induced bacteriorhodopsin LB films’ fast photoelectric dynamics

Ten layers of oriented bacteriorhodopsin (BR) LB films are prepared on ITO conductive glass to constitute an ITO electrode/BR LB films/KCl solution/Cu electrode wet photocell. A Q-switched double frequency Nd:YAG laser with 10 Hz repetitive rate and 8 ns pulse width is used to excite the BR LB films. The photoelectric signal is directly captured by a 300 MHz digitizing oscilloscope. A theory on the BR photoelectric dynamics is established. By nonlinear least square fitting of the experimental curves acquired at different time bases, the experimental equation corresponding to the theoretical model is obtained, and the charge displacements and the decay time constants for each step in the BR photocycle are calculated. Project supported by the State Key Laboratory of Transient Optics and Technology and the Bureau of Foundamental Researches, Chinese Academy of Sciences.     

Analytic formulae of bound-free Gaunt factor under the hydrogenic Coulomb field

In this paper, analytic formulae of the bound-free (photoelectric) Gaunt factor for nl from 6s to 10l are given. The formulae are obtained by using hydrogen-like Coulomb wave functions. Analytic results are presented and agree very well with those of numerical method. The formulae are useful to calculate conveniently the bound-free cross-sections and absorption coefficients in plasma simulations.     

Soft Polymer Janus Nanoparticles at Liquid–Liquid Interfaces

Soft polymeric Janus nanoparticles (JNPs), made from polystyrene‐b‐poly(butadiene)‐b‐poly(methylmethacrylate), PS‐PB‐PMMA, triblock terpolymers, assemble into a monolayer at the water–oil interface to reduce interfacial tension. The extent to which the polymer chains can deform influences the packing density of the JNPs at the interface. The longer the polymer chains are relative to the core, the softer are the JNPs, resulting in a JNPs assembly with a lower initial lateral packing density. The interfacial activity of JNPs can be further tuned by complexation of the PMMA chains with lithium ions that are introduced into the water phase. This work provides a fundamental understanding of soft JNPs packing at the water–oil interface and provides a strategy to tailor the areal density of soft JNPs at liquid–liquid interface, enabling the design of smart responsive structured‐liquid systems.     

叶绿素、染料体系光电效应的研究

叶绿素光电性质的研究有特殊意义.70年代开始国内外已有很多报道, 它们有整流、光导、光伏和光解水制取氢和氧等性质^[1-5].我们也报道过叶绿素a/聚乙烯醇夹层电池的研究^[6-8]。     

骨架结构多孔TiO2薄膜增强染料敏化太阳能电池性能

以空心球状TiO₂为基体、以片状TiO₂为骨架,采用刮刀法制备了染料敏化太阳能电池的多孔TiO₂光阳极薄膜。光电转化效率测试结果表明,当作为骨架支撑材料的片状TiO₂含量为20wt%时,光阳极薄膜组装成太阳能电池的光电转化效率达到最高值4.53%,比商业P₂₅制备的无孔无骨架TiO₂薄膜电池(4.06%)及无骨架结构的多孔TiO₂薄膜电池(4.17%)的性能均有显著提高。当片状TiO₂的最佳含量为20wt%电池薄膜厚度为33μm时,太阳能电池光电转化效率进一步提升为7.06%。光电性能增强的原因是骨架结构有利于快速传输电子并增大染料吸附量。本研究通过设计制备具有骨架结构的多孔TiO₂薄膜为提高染料敏化太阳能电池性能提供了新的思路。     

硫醇-烯/炔点击化学制备有机/无机杂化材料

有机/无机杂化材料因其独特、优异的结构和性能已经成为目前材料领域的研究热点,硫醇-烯/炔点击化学是近年发展起来的一类新型点击化学,以其反应条件温和、速率快、产率高、产物容易分离以及高度选择性等优点受到国内外研究者的广泛关注。本文综述了近年来硫醇-烯/炔点击化学制备有机/无机杂化材料的研究进展,重点介绍了利用硫醇-烯/炔点击化学制备硅类、碳类、金属及金属氧化物类有机/无机杂化材料,并归纳了这些有机/无机杂化材料在生物医用、环境保护、光电材料等方面的应用,最后展望了硫醇-烯/炔点击化学制备有机/无机杂化材料未来的发展方向。