Real‐Time Probing Nanopore‐in‐Nanogap Plasmonic Coupling Effect on Silver Supercrystals with Surface‐Enhanced Raman Spectroscopy

Nanopore structures have displayed attractive prospects in diverse important applications such as nanopore‐based biosensors and enhanced spectroscopy. However, on the one hand, the fabrication techniques to obtain sub‐10 nm sized nanopores so far is very limited. On the other hand, the electromagnetic enhancement of nanopores is still relatively low. In this work, using a facile chemical etching strategy on 2D plasmonic Ag nanoparticle supercrystals, fine nanopore arrays with sub‐10 nm pore size have been successfully fabricated and a “nanopore‐in‐nanogap” hybrid plasmon mode has been investigated. An in situ etching and surface‐enhanced Raman spectroscopy (SERS) detection indicate that novel hybrid plasmon structure may create an enhanced electromagnetic coupling and increase SERS signal at ≈10× magnification. The breaking of plasmon bonding dipolar mode and generation of antibonding‐like plasmon mode contribute to this enhanced electromagnetic coupling. The facile etching strategy, as a common approach, may open the doors for the fabrication of nanopores in various compositions for numerous applications.     

Far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge triple-junction solar cell under forward DC bias

The far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge solar cell are investigated under forward DC bias at room temperature in dark conditions. An electroluminescence viewgraph shows the clear device structures, and the electroluminescence intensity is shown to increases exponentially with bias voltage and linearly with bias current. The results can be interpreted using an equivalent circuit of a single ideal diode model for triple-junction solar cells. The good fit between the measured and calculated data proves the above conclusions. This work is of guiding significance for current solar cell testing and research.     

基于c-Si(P)衬底的a-Si/c-Si异质结模拟研究

本文中研究了影响 a-Si/c-Si 异质结界面复合的主要因素： 表面固定电荷 ,缺陷态载流子俘获界面： ,以及界面缺陷态密度 。当缺陷能级 接近c-Si本征能级,且 满足时,缺陷态复合中心复合速度达到最大。AFORS-HET 软件模拟显示, a-Si/c-Si界面能带不连续显著影响电池Voc、界面缺陷态密度大于1*1010 cm-2.eV-1时,界面态密度的增加会严重降低电池Voc,但其对电池电流密度影响不大。对于c-Si (P)/a-Si (P ) 结构异质结,C-Si衬底的势垒 和a-Si材料内的势垒 对降低c-Si (P)/a-Si (P ) 结构的接触电阻和界面复合速度,表现各不相同。     

High breakdown voltage InGaAs/InP double heterojunction bipolar transistors with fmax=256 GHz and BVCEO= 8.3 V

正An InGaAs/InP DHBT with an InGaAsP composite collector is designed and fabricated using triple mesa structural and planarization technology.All processes are on 3-inch wafers.The DHBT with an emitter area of 1 x 15μm~2 exhibits a current cutoff frequency f_t = 170 GHz and a maximum oscillation frequency f_(max) = 256 GHz.The breakdown voltage is 8.3 V,which is to our knowledge the highest BV_(CEO) ever reported for InGaAs/InP DHBTs in China with comparable high frequency performances.The high speed InGaAs/InP DHBTs with high breakdown voltage are promising for voltage-controlled oscillator and mixer applications at W band or even higher frequencies.     

矢量偏振光束产生新方法

为了解决现有矢量偏振光束(VPB)产生装置结构复杂、成本高等问题,提出了利用一种由多个线型偏振器件构成的同心圆环装置即显偏器(PAF)产生矢量偏振光束的新方法。基于显偏器的特殊结构特点,由LED光源输出的自然光束经显偏器,可产生角向偏振光束(APB),再经两个快轴成45°角的半波片可将角向偏振光束转换成径向偏振光束(RPB)。采用此方法获得的矢量偏振光束经线偏振片验证其光强分布情况,研究发现所得结果与已发表的实验结果相符,验证了该方法的有效性和实用性。     

低相位噪声微波频率源的研究

通过对微波频率源相位噪声的分析,针对一个C波段微波频率源低相位噪声的要求,对比分析了直接倍频、数字锁相以及高频鉴相之后再倍频三种方案之间的相位噪声差别。最终得出采用直接在超高频(UHF)波段对输入信号进行模拟鉴相并锁定之后再倍频才能达到所要求的相位噪声指标。对制成的样品进行了测试,取得了预期的相位噪声指标。该C波段微波频率源的相位噪声可以达到:≤-120 dBc/Hz@1 kHz,≤-125 dBc/Hz@10 kHz,≤-130dBc/Hz@100kHz,≤-140 dBc/Hz@1 MHz。直接在UHF波段进行高频鉴相的技术,通过提高鉴相频率大幅降低了微波锁相频率源的相位噪声。     

染料调谐激光器中ASE的有效抑制

染料的放大自发辐射（以下简称ASE)是染料激光器的一个十分严重的问题。为了滤除ASE，提高信噪比，获得高纯度可调谐激光，人们已作各种尝试，在一定程度上得到了改善。我们采用了一种饱和吸收和偏振的新技术，有效地抑制了ASE，达到窄带ASE背景0.01%。     

慢流CO_2激光器最佳冷却条件的实验研究

螺旋水冷慢流CO_2激光器件比普通慢流器件输出激光功率高16%。瓷管慢流器件气、水逆流较气、水顺流运用激光功率高7.6%。给出了最佳冷却条件。     

A 1 V, 0.53 ns, 59 μW Current Comparator Using Standard 0.18 μm CMOS Technology

Wireless Personal Communications - This letter aim to propose a current comparator based on simple current mirror which use single amplifier to reduce input offset, the improving symmetry current...     

电动汽车“有意”及“无意”天线电磁干扰案例解析

随着电动汽车零部件所处的车内、外电磁环境日趋复杂,车载部件的电磁干扰问题备受关注。结合实车电磁干扰案例,对无钥匙进入及启动系统与真空助力系统的受干扰机理、优化措施进行了重点论述。案例表明:电动汽车后期加装行车记录仪可能给PEPS系统带来同频干扰;高功率短波电台通过"无意"天线也可以造成车载真空泵控制器异常使能甚至损坏。