Eu3+,Li+共掺杂ZnO薄膜结构与发光性质的研究

为了研究Eu3+,Li+共掺杂的ZnO薄膜结构与发光性质,采用脉冲激光沉积方法在P型单晶Si（111）衬底上制备了Eu3+,Li+共掺杂的ZnO薄膜,其中,Eu3+作为发光中心,而Li+作为低价电荷的补偿离子和发光敏化剂。分别对样品进行了X射线衍射谱测试和光致发光谱分析。得出的数据中X射线衍射谱显示,Eu3+,Li+共掺杂的ZnO薄膜具有c轴择优取向,X射线衍射谱中除ZnO晶向以外没有出现其它结晶峰;Eu3+,Li+共掺杂的ZnO薄膜的光致发光谱与ZnO纯晶体薄膜的发射光谱基本相似,但是掺杂ZnO薄膜的紫外发光峰却出现红移现象,峰值位于382nm处,且发光峰也不尖锐。当以395nm的激发光照射样品时,在光致发光光谱中观察到了稀土Eu3+在594nm,613nm附近的特征发光峰。结果表明,掺杂元素Eu3+,Li+均已进入到ZnO晶格中,形成了以Eu3+为发光中心的ZnO纤锌矿结构。     

纳米SiO2基质中Eu3+的发光特性

采用溶胶凝胶法(sol-gel)制备了Eu3+掺杂SiO2基质发光材料,分别用荧光(PL)光谱、原子力显微镜(AFM)、扫描电镜(SEM)等分析手段对样品进行了表征,研究了退火温度以及掺杂浓度对发射光谱的影响,并对其发光机制进行了分析.薄膜样品在258 nm光激发下,在620 nm,667 nm处出现了比较少见的双峰红光发射,而620 nm处的光发射最强,说明Eu3+离子处在对称性较低的配位环境中.退火处理温度对样品的发射光谱影响很大,经900 ℃退火处理的样品发射强度最强.随着掺杂浓度的变化,改变了Eu3+ -O2-间的距离,在相同紫外光激发下O2-外层的电子迁移到Eu3+ 4f轨道上的能量变化,使得谱线位置出现了移动.     

Eu3+掺杂钙钛矿结构的MSnO3(M＝Ca,Sr,Ba)发光粉的发光特性研究

利用高温固相反应法合成了MSnO3:Eu3+ (M=Ca,Sr,Ba)发光粉末样品,采用X射线衍射技术和荧光光谱等测试手段对样品的结构、固相反应机理及发光特性进行了研究.结果表明:Eu3+离子的掺杂未明显改变MSnO3 (M＝Ca,Sr,Ba)的晶体结构.荧光光谱测试显示Ca0.98Eu0.02SnO3样品的发射以电偶...     

退火对6H-SiC晶体的光学性质及光致发光的影响

利用双光束分光光度计对高温退火前后的掺氮和未掺杂6H-SiC晶体的透射及反射谱进行了分析,发现无论退火前后,两种SiC晶体在紫外区均存在强烈的吸收.在可见和近红外区,尤其是未掺杂SiC样品具有很高的透射率,退火后,两种样品的透射率均明显提高.利用荧光分光光度计研究了退火前后样品的光致发光特性,结果表明:在390 nm Xe灯激发下.两种样品在417 nm和436 nm处均可观察到蓝光发射,417 nm处的发光归结于C簇的发光,436 nm处的发光机理为从晶粒的核心激发载流子转移到晶粒表面,并与其上的发光中心辐射复合;同时,掺氮SiC在575 nm处还存在发光峰,为氮掺入后引起的非晶SiC的发光,在325 nm Xe灯激发下,525 nm处存在发光峰,其详细发光机制有待进一步研究.     

电纺丝方法制备GaN：Eu2+ 纳米纤维与发光特征

通过结合静电纺丝和氨化技术方法合成了Eu2 掺杂的GaN（GaN：Eu2 ）纳米纤维。SEM和TEM图像显示纳米纤维由尺寸均匀分布的GaN纳米颗粒组成。XRD测试结果表明GaN：Eu2 样品主要为六方相GaN（h-GaN）,其平均粒径为7.3 nm。进一步的拉曼测试结果显示出现了两个额外的GaN拉曼位移,波数分别位于252和422 cm-1。室温光致发光谱表明GaN基质中的Eu 2 在407 nm处产生了强烈的特征蓝色发光峰。     

Ho3+掺杂Al2O3粉体、薄膜的结构及其发光性能

采用高能球磨法及脉冲激光沉积法(PLD)分别制备了不同浓度的Ho3+∶Al2O3纳米粉体及薄膜,利用X射线衍射仪(XRD)、分光光度计、荧光光谱仪等分析手段研究了Ho3+离子掺杂对Al2O3结构及发光性能的影响。XRD图谱显示粉体样品为六方α-Al2O3结构,薄膜样品为体立方γ-Al2O3结构。1wt%Ho3+掺杂的Al2O3纳米粉体在454nm、540nm附近出现由Ho3+离子能级跃迁引起的吸收峰。采用579nm的激发光源对样品进行荧光光谱检测,发现两种样品在466～492nm波段均出现F+心所引起的缺陷发光峰,且发光峰的强度随Ho3+浓度的增加而增强。     

KSrPO_4:Eu~(3+)红色发光材料的制备及性能研究

采用高温固相合成工艺制备了KSrPO4:x Eu3+红色发光材料,通过X射线衍射、荧光光谱、量子效率仪、封装对发光材料的晶体结构及发光特性进行了研究。XRD表明KSrPO4晶体结构并没有随着Eu3+的掺入而发生变化;荧光光谱表明KSrPO4:Eu3+在394 nm处存在最强激发峰,发射光谱最强发射峰为612nm;量子效率研究表明随着Eu3+掺杂量的增加,量子效率先增后降,在Eu3+掺杂量x=0.04时,量子效率存在最大值51%;封装光源的显色指数为83,色温3497 K,并且随着电流的变化色坐标(X,Y)基本保持不变,因此,KSrPO4:Eu3+红色发光材料作为近紫外激发的红色发光材料具有一定的潜力。     

基于PLD法制备ZnO:Eu3+,Li+薄膜的发光性质研究

采用脉冲激光沉积(PLD)技术在Si(111)衬底上生长了Eu3+、Li+共掺杂的ZnO薄膜。分别对样品进行了X射线衍射(XRD)谱测试和光致发光(PL)谱分析,重点研究了退火处理对样品结构和发射光谱的影响。XRD谱测试表明,样品具有很好的C轴择优取向。PL谱研究表明,当用325nm光激发样品时,样品的发射光谱仅由ZnO基质的紫外发射和蓝光发射组成,并没有发现稀土Eu3+的特征发光峰;样品的蓝光发射源于电子从Zn填隙形成的浅施主能级到Zn空位形成的浅受主能级跃迁;和真空中退火的样品相比,O2中制备的样品的蓝光发射减弱,紫外发光增强。用395nm的光激发时,退火前样品分别在594nm和613nm处存在两个明显的Eu3+特征发光峰,退火后的样品仅发现Eu3+位于594nm的特征发光峰,这表明,退火处理不利于稀土离子的特征发射,但O2中退火的样品ZnO基质红绿波段发射光谱明显增强。     

Al掺杂ZnO薄膜的表面形貌和光学性质

用原子力显微镜、紫外-可见分光光度计和荧光光谱仪观察采用溶胶-凝胶法制备的Al掺杂ZnO薄膜的表面形貌、透射光谱和光致发光谱.结果表明,Al掺杂量为0.5at 9/6的ZnO薄膜经550℃退火处理后,粗糙度为1.817,Al掺杂量为1.0at%的ZnO薄膜经600℃退火处理后,粗糙度增大到4.625.样品在可见光范围内的平均透过率均大于80%.当激发波长为325 nm时,在397 nm(3.13 eV)附近出现紫外发光峰;当激发波长为360 nm时,在443 nm(2.80 eV)附近出现蓝色发光峰.探讨了样品的蓝光发光机制.     

光学碱度与能量传递对Bi/Yb~(3+)共掺杂锗酸盐玻璃近红外发光性质的影响（英文）

采用传统高温熔融法制备了Bi/Yb~(3+)共掺杂锗酸盐玻璃,通过吸收光谱、近红外光谱和荧光衰减寿命测试,研究了玻璃样品的近红外发光性质.研究结果表明,玻璃样品在980 nm或808 nm激光激发下,均能同时观察到Yb~(3+)离子和Bi离子的近红外发光,Yb~(3+)离子与Bi离子之间存在相互能量传递.随着Yb~(3+)离子浓度的增加,玻璃基质的光学碱度和Yb~(3+)离子到Bi离子的能量传递效率均增加,讨论了能量传递效率的提高对Bi离子发光的增强作用与光学碱度增加对Bi离子发光的削弱作用的竞争影响机制,获得了Bi/Yb~(3+)离子共掺杂锗酸盐玻璃的近红外发光的机理.     

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