Er^3＋在氟氧化物玻璃陶瓷中的荧光衰减特性

氟氧化物玻璃陶瓷是具有氧化物的机械性能和氟化物的低声子能量的新型上转换发光材料。本文首次研究了Er^2 -Yb^3 共掺杂时Er^3 的荧光衰减特性。研究结果表明,由于室温下声子的参与使不同稀土离子之间更容易实现能级匹配,增强了交叉弛豫过程,并使664nm辐射在室温下有较长的寿命,这一结果有利用4F9/2 能级做中间能级实现转换发光。     

Er~(3+),Yb~(3+)掺杂氟氧化物微晶玻璃上转换发光的研究

测量了 Er3+掺杂氟氧化物微晶玻璃、Er3+ ,Yb3+掺杂氟氧化物微晶玻璃退火前后 3种样品的吸收光谱、激发光谱、上转换发光光谱及其强度随泵浦光强的变化 ,对比讨论了其上转换发光特性     

Er3+/Yb3+共掺氟氧微晶玻璃的光谱性质及Judd-Ofelt理论分析

制备了新的Er3+/Yb3+共掺氟氧硅酸盐微晶玻璃,测试了荧光光谱、吸收光谱。研究了氟氧化物微晶玻璃中Er3+离子的上转换发光特性,采用Judd-Ofelt理论对样品光谱进行了分析,拟合得到了强度参数,Ω2=4.4756,Ω4=1.0059,Ω6=1.2098。计算了样品的辐射寿命、跃迁几率、荧光分支比等光谱参数。结果表明,样品通过热处理形成了氟化物微晶,降低了声子能量,提高了上转换效率。绿光、红光上转换荧光强度比玻璃样品增强约2到3倍。Judd-Ofelt理论分析表明Er3+/Yb3+共掺氟氧微晶玻璃具有较高的上转换效率,是制作微型激光器和三维立体显示的优良材料之一。     

OH-对掺Er3+碲酸盐玻璃上转换发光的影响

研究了碲酸盐玻璃的拉曼光谱和红外光谱,分析了OH-对掺Er3 碲酸盐玻璃上转换发光的影响机制。实验结果表明,氧氟碲酸盐玻璃(TPF)的声子能量高于氧氯碲酸盐玻璃(TPC)的声子能量,但是Er3 掺杂TPF玻璃上转换发光强度也高于Er3 掺杂TPC玻璃。除水实验发现这种现象可归因于OH-的影响。随OH-浓度降低,Er3 的荧光寿命和上转换荧光都增加。在实验中,OH-对Er3 上转换发光的影响大于声子能量对Er3 上转换发光的影响,导致Er3 掺杂TPF玻璃上转换发光强度高于Er3 掺杂TPC玻璃的上转换发光。研究结果有助于进一步提高Er3 的发光效率。     

NaGdF4:Er3+,Tm3+,Yb3+发光粉的制备及上转换白光发射

采用水热法制备了系列掺杂不同Yb3+浓度的NaGdF4:Er3+,Tm3+,Yb3+上转换发光粉,并对其结构和上转换发光性能进行了表征。X射线衍射(XRD)研究结果表明,所有样品均为六方结构NaGdF4。Yb3+的浓度对NaGdF4晶相的面间距有少许影响。在980nm红外光激发下,NaGdF4:Er3+,Tm3+,Yb3+发光粉上转换光谱显示绿光、红光和蓝光发射,它们分别来自于Er3+的2H11/2,4S3/2→4I15/2跃迁发射、4F9/2→4I15/2跃迁发射,Tm3+的1G4→3H6跃迁发射。NaGdF4:Er3+,Tm3+,Yb3+发光粉的绿光与红光、蓝光与红光发射的相对强度受Yb3+浓度的影响。讨论了可能的上转换发光机制。在980nm红外光激发下,NaGdF4:0.05%Er3+,0.3%Tm3+,50%Yb3+发光粉显示亮白光,其色坐标为(0.342,0.331)。上转换白光发射可通过调控NaGdF4:Tm3+,Er3+,Yb3+发光粉中Yb3+掺杂浓度获得。     

a-SiN_xO_y∶Er~(3+)薄膜的光致发光

采用射频 (RF)反应共溅射法制备了 a- Si Ox Ny∶ Er3+薄膜 ,在不同温度下进行退火处理 ,并测量了样品的可见及红外发光 PL谱 ,观察到 Er3+ 在 5 5 0 nm、5 2 5 nm和 15 32 nm的发光以及基质在 6 2 0 nm和 72 0 nm的发光 .发现退火能明显增强 Er3+ 的发光且对可见和红外发光的影响不同 ,讨论了退火明显增强 Er3+ 发光及退火对可见和红外发光影响不同的机理 .测量了 Er3+ 可见发光的变温 PL谱 ,讨论了退火对 Er3+ 不同能级辐射跃迁几率的影响 .根据基质发光随退火温度的变化 ,分析了基质发光峰的起源     

Yb3+对掺铒碲酸盐玻璃红外和上转换发光的影响

研制了Er3+/Yb3+共掺TeO2-ZnO-La2O3玻璃,测试了Er3+离子的吸收谱、荧光谱和上转换发光谱,系统研究了975 nm抽运下Yb3+离子对于Er3+离子1.5 μm波段荧光性能及其上转换发光性能的影响.结果表明,随着碲酸盐玻璃中Yb2Os含量的增加,Yb3+离子对Er3+离子的能量传递增强,Er3+离子1.5 μm波段的荧光强度和上转换发光强度相应增大,但后者相对于前者增加更为迅速.通过对粒子数速率方程的理论模拟,计算结果与实验测量结果较为一致,表明Er3+/Yb3+共掺碲酸盐玻璃是一种优良的潜在上转换激光器增益介质.对上转换发光分析表明,强烈的绿光和红光激发是基于双光子的吸收过程.     

高浓度铒离子掺杂钨酸镱钾激光晶体上转换发光研究(英文)

首次采用泡生法生长了掺铒钨酸镱钾(分子式:Er3+:KYb(WO4)2,简称:Er:KYbW)激光晶体。室温下测试了该晶体的吸收及上转换发射光谱。在荧光光谱中,观察到3个较为明显的上转换发射带,分别位于470~560nm,645~675 nm,750~850 nm。其中,位于533 nm处的上转换绿光强度最大。基于能量匹配原理分析了晶体上转换发光基质,结果表明,上转换红光和绿光的发光渠道均为双光子过程。根据J-O理论,计算了光谱参数,强度参数为:Ω2=16.342×10-20cm2,Ω4=4.183×10-20cm2,Ω6=1.264×10-20cm2;对应于绿光4S3/2-4I15/2跃迁的荧光分支比为76.37%,荧光寿命为278μs。这些光学参数表明Er:KYbW激光晶体可实现高效上转换绿光发射。     

应用于白光显示的碲酸盐玻璃上转换发光特性

用高温熔融法制备了Tm3+/Er3+/Yb3+共掺碲酸盐玻璃(TeO2-ZnO-La2O3)样品,测试了玻璃样品的吸收光谱和上转换发光光谱,分析了上转换发光机理。结果发现:在975 nm,波长激光二极管(LD)激励下,制备的碲酸盐玻璃样品可以观察到强烈的红光(662 nm)、绿光(525、546 nm)和蓝光(475 nm)三基色上转换发光,分别对应于Er3+的4F9/2→4I15/2,2H11/2→4I15/2、4S3/2→4I15/2和Tm3+的1G4→3H6能级跃迁;随着Yb3+掺杂含量和泵浦功率的增加,样品的上转换发光强度都得到了一定程度的提高;通过调整稀土掺杂的浓度,得到了接近于标准白光(EE)发射。     

a-SiNxOy∶Er3+薄膜的光致发光

采用射频(RF)反应共溅射法制备了a-SiOxNy∶Er3+薄膜,在不同温度下进行退火处理,并测量了样品的可见及红外发光PL谱,观察到Er3+在550nm、525nm和1532nm的发光以及基质在620nm和720nm的发光.发现退火能明显增强Er3+的发光且对可见和红外发光的影响不同,讨论了退火明显增强Er3+发光及退火对可见和红外发光影响不同的机理.测量了Er3+可见发光的变温PL谱,讨论了退火对Er3+不同能级辐射跃迁几率的影响.根据基质发光随退火温度的变化,分析了基质发光峰的起源.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.