基于 InSe/MoTe2 异质结构的超灵敏宽光谱光电探测器

基于光栅效应的二维材料垂直结构可实现高灵敏度和宽光谱光探测器。本文报告了一种基于硒化铟（InSe）/二碲化钼（MoTe₂）垂直异质结构的高灵敏度光电探测器,该探测器在 365~965 nm 波长范围内具有出色的宽光谱探测能力。顶层的InSe用作调节沟道电流的光栅层,MoTe₂ 则用作传输层。通过结合两种材料的优势,该光电探测器的响应时间为 21.6 ms,比探测率在365 nm光照下可以达到1.05×10¹³ Jones,在965nm光照下也可达到10⁹ Jones数量级。外量子效率可达 1.03×10⁵%,显示出强大的光电转换能力。     

基于InAs/GaAs量子点-石墨烯复合结构的肖特基光电探测器研究

石墨烯具有电子迁移率高、透过率高(T≈97.7%)且费米能级可调的特性。砷化镓的电子迁移率比硅的大5到6倍。引入砷化铟量子点后,光电探测器具有低暗电流、高工作温度、高响应率和探测率的特点,因而可被用于制备响应快、量子效率高和光谱宽的光电探测器。对基于InAs/GaAs量子点-石墨烯复合结构的肖特基结的I-V特性和光电响应进行了研究。结果表明,在0 V偏压下,该器件在400 nm～950 nm均有响应,峰值响应率可达0.18 A/W;在反向偏压下,器件的峰值响应率可达到0.45 A/W。通过对暗电流随温度变化的特性进行分析,得到了InAs/GaAs量子点-石墨烯肖特基结在室温附近以及80 K附近的势垒高度。     

基于二维碲烯的太赫兹光电探测器

制备了金属-碲烯-金属的太赫兹光电探测器,实现了毫米波-太赫兹波下的光探测。结果表明,基于对数天线碲烯的太赫兹光电探测器在零偏压下具有较高的光响应率（40 mA /W,0.12 THz）,响应时间为8 μs,噪声等效功率（NEP）为4 pW·Hz^-0.5。研究结果为高性能室温太赫兹光探测提供了一种新的发展路径。     

基于硫化铅薄膜的宽光谱光电探测器

硫化铅因具有高载流子迁移率、高光吸收系数等出色的光电特性,所以在光电探测领域备受关注。文章通过化学浴沉积(CBD)的方法合成了高质量硫化铅薄膜,并基于厚度约为500 nm的硫化铅薄膜构建了光电探测器。光电测试表明该器件具有从365～1 650 nm的宽光谱响应。进一步的光电特性分析表明,该器件在光强为18.6 μW cm^-2的1 050 nm光照下,响应度和增益高达9.56 A W^-1和11.32,为低成本宽光谱的光电探测器的发展提供了一个有利的平台。     

PbSe光电导焦平面阵列探测器

应用半导体非平衡载流子连续性方程模拟了PbSe光电导红外探测器参数对光电响应的影响,实验研制了小规模像元的x-y寻址型PbSe光电导焦平面阵列（FPA）探测器,像元尺寸为500 μm×500 μm,像元间距为500 μm。实验表征了PbSe FPA探测器像元的光电响应性能,有效像元率达到了100%。500 K温度黑体辐射和3.0V偏压下像元的黑体响应率的范围是70~146 mA/W,平均响应率和平均探测率分别达到了110 mA/W和5.5×10⁹。像元的噪声等效温差（NETD）范围是15~81mK,平均噪声等效温差为32 mK。使用中波红外成像装置,初步演示了PbSe FPA探测器对350~450℃热辐射目标的红外成像。为后续研制高密度像元PbSe FPA探测器奠定了基础。     

n-ZnO/p-GaAs异质结光电探测器光电特性研究

利用脉冲激光沉积(PLD)技术在p-GaAs外延片 上生长了n型ZnO薄膜,制备了n-ZnO薄膜/p-GaAs 异质结光电探测器原型器件。X射线衍射(XRD)及扫描电子显微镜(SEM)测试结果表明, 生长在GaAs表面上的ZnO薄膜具有较高的结晶质量。在反向偏压下,器件表现出良好的近红 外探测性能,工作电压在－0.5V到－4.0V时,光谱响应 度峰值在850nm附近;当反向电压为－2.0V 时,光响应度达到饱和 ,响应度峰值达到10.17A/W。而比探测 率峰值则在－2.0V达到最大值2.06×10¹⁰ cm Hz1/2/W, 之后下降。反向工作电压下的光谱响应度和比探测率曲线表明, 器件对850nm附近的近红外光具有较强的选择性(FWHM 约为30nm)。     

用溶液法制备钙钛矿纳米线光电探测器

作为一种优秀的光吸收半导体材料,有 机-无机杂化钙钛矿被广泛应用于光电领域。为了制备高 性能光电探测器件,采用溶液法制备了高度有序、超长的CH3NH3PbI3 纳米线,并将其应用于Au/CH3NH3PbI3/Au平面型光电探测器。该 器件具有宽的工作波段,在紫外-可见光-近红外(365~808 nm) 光谱范围内均有响应。其最大光响应度达到3.81 A·W-1,比探 测率为3.7×1011 Jones,开关比为4.9×103,光响应时间约 为7 ms。由于具有优异的光探测能力,该器件拥有广阔的应用前景。     

4H-SiC 雪崩光电探测器中倍增层参数的优化模拟

应用ATLAS模拟软件,设计了吸收层和倍增层分离的（SAM）4H-SiC 雪崩光电探测器（APD）结构。分析了不同外延层厚度和掺杂浓度对器件光谱响应的影响,对倍增层参数进行优化模拟,得出倍增层的最优化厚度为0.26μm,掺杂浓度为9.0×1017cm^-3。模拟分析了APD的反向IV特性、光增益、不同偏压下的光谱响应和探测率等,结果显示该APD在较低的击穿电压66.4V下可获得较高的倍增因子105;在0V偏压下峰值响应波长（250nm）处的响应度为0.11A/W,相应的量子效率为58%;临近击穿电压时,紫外可见比仍可达1.5×103;其归一化探测率最大可达1.5×1016cmHz ^1/2 W^-1。结果显示该APD具有较好的紫外探测性能。     

石墨烯MIS结宽光谱光电特性的研究

Ge基光电探测器具有独特的通信带宽响应特性和良好的CMOS工艺兼容性,在光电探测方面具有广阔的应用前景。但目前商用探测器的响应波段普遍局限在某一波段,难以满足多波段融合、小型化的探测需求。因此,通过在多层石墨烯和N型Ge之间引入薄的SiO2界面层,制备了基于石墨烯金属-绝缘层-半导体(MIS)结的光电探测器,分析了SiO₂的厚度以及石墨烯层数对MIS结器件性能的影响,并测试了器件的光谱响应范围、电流-电压曲线、响应度、开关比等光电特性。结果表明,该器件在254～2200 nm波段内均有响应,在980 nm处的响应度和开关比达到峰值,分别为78.36 mA/W和1.74×10³,上升时间和下降时间分别为1 ms和3 ms。     

n-ZnO/p-GaN异质结紫外探测器及其光电性能研究

利用脉冲激光沉积(PLD)方法在p-GaN衬底上沉积了n-ZnO薄膜,构造了n-ZnO/p-GaN异质结型紫外(UV)光-电探测器原型器件,在(UV)光照条件下测试了器件的光电性能。扫描电镜(SEM)和X射线衍射(XRD)测试结果表明,ZnO薄膜具有很好的结晶质量;I-V曲线显示,器件在黑暗和光照环境下都表现出明显的整流行为;光谱响应曲线表明,器件响应度峰值出现在364nm附近,当反向电压为-5V时光电流达到饱和,此时响应度峰值达到1.19A/W。不同反向工作电压下的光谱探测率曲线表明,器件对364nm附近的UV光有较强的选择性,在-2V偏压下具有最佳的探测率,其探测率峰值达到8.9×1010 cm·Hz1/2/W。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks