界面过渡层对黄光OLED发光性能的影响研究

研究了黄光OLED发光层间加入界面过渡层对OLED发 光性能的影响。实验制备新型黄光OLED的发光层结构为 CBP:R-4B/CBP:Girl:R-4B/CBP:GIrl,对比OLED的发光层结构为CBP:10%R-4B/CBP:10%GIrl、CBP: 10%GIrl/CBP:10%GIrl10%R-4B/CBP:10%R-4B和CBP:10%GIrl/CBP:10%R-4B。结果表明,在对比器 件的发光层界面间加入过渡层可显著提高器件的发光亮度和发光效率,新型器件在13V电压 下、电流密度为40.29mA/cm²时,发光亮度和发光效率分别达到 了11120cd/m²与27.59cd/A,较未加入过渡层的器件分别提 高了265%56.18%。分析认为,过渡层的 加入消除了由不同发光层间严格的界面效应而造成的界面缺 陷,增加了载流子传输速率与激子的复合效率,从而提升了器件的发光性能。     

有机层界面电荷聚集及其对OLED性能的影响

采用金属Al、合金Mg:Ag以及复合层LiF-Al作为阴极材料,利用真空加热蒸镀法制备了异质结有机发光器件(OLED),研究了阴极材料与器件有机层界面电荷聚集之间的关系.结果表明,界面电荷聚集与阴极材料密切相关,LiF-Al复合层阴极器件的界面聚集电荷最少,而Al金属阴极器件的界面聚集电荷最多.同时,通过测试器件的光电性能,进一步研究了阴极材料对OLED发光特性的影响.实验结果显示,LiF-Al复合层阴极器件具有最大的发光亮度和效率、最小的启亮电压和驱动电压.     

功能层界面制备方法对OLED性能的影响

在功能层界面处采用各功能材料共蒸的方法,制备了典型的绿光有机发光器件(OLED)。器件的结构为ITO/NPB(37nm)/(NPB:Alq3)(3nm)/Alq3(27nm):C545T(3%)/Alq3(20nm)/LiF(1nm)/Al(100nm),并与传统的制备方法进行了比较。结果发现,起亮电压从4.5V降低到2.5V,最高耐压从16V提高到21V,最大亮度从13 940cd/m2提高到24 630cd/m2,发光效率由7.0cd/A提高到11.4cd/A。结果表明,本文方法有利于载流子传输,可以有效提高激子形成概率,提高了OLED发光效率。     

以ZnO为空穴缓冲层的高效率有机电致发光器件

研制了在传统双层有机电致发光器件(OLED) ITO/NPB/AlQ/Al的阳极与空穴传输层间加入ZnO缓冲层的新型器件.研究了加入缓冲层后对OLED性能的影响,并比较了新型与传统OLED的性能,结果表明,新型器件比传统器件的耐压能力有了显著提高;当电压达到7 V时,发光效率提高了35%.分析认为,ZnO缓冲层的加入,改善了界面, 减少了漏电流,并且阻碍了空穴的注入,有利于改善空穴和电子的注入平衡,提高复合效率.     

蓝绿色磷光OLED的制备及发光性能研究

以mCP为主体发光材料,蓝绿色磷光染料BGIr1作为掺杂剂,制备了6种不同BGIr1掺杂量的蓝绿色磷光有机电致发光器件(OLED),研究了不同掺杂量对蓝绿色磷光OLED器件发光特性的影响。制得器件的结构为ITO/MoO3(20nm)/NPB(40nm)/mCP:BGIr1(x%,30nm)/BCP(10nm)/Alq3(20nm)/LiF/Al(100nm),其中x%为发光层中磷光染料BGIr1的掺杂量(质量分数)。结果表明,BGIr1掺杂量为18%时,获得器件的发光性能最佳。18%BGIr1掺杂器件在488nm和512nm处获得两个主发射峰,当电流密度为26.5mA/cm2时,获得最大发光效率为6.2cd/A;在15V驱动电压下,获得最大亮度为6 970cd/cm2,CIE坐标为(0.17,0.31)。这说明,BGIr1掺杂改善了器件的发光亮度和色纯度,提高了器件的发光效率。     

空穴传输层厚度对有机发光二极管性能的影响

采用聚乙烯基咔唑(PVK)作为空穴传输层,8-羟基喹啉铝(Alq3)作为发光层,制备了结构为ITO/PVK/Alq3/Mg∶Ag/Al的有机发光二极管(OLED),通过测试器件的电流-电压-发光亮度特性,研究了空穴传输层厚度对OLED器件性能的影响,优化了器件功能层的厚度匹配.实验结果表明,OLED的光电性能与空穴传输层的厚度密切相关,空穴传输层厚度为15nm时,OLED器件具有最低的启亮电压,最高的发光亮度和最大的发光效率.     

蓝绿色磷光OLED的制备及发光性能研究

以mCP为主体发光材料,蓝绿色磷光染料BGIr1作 为掺杂剂,制备了6种不同BGIr1掺杂量的蓝绿色磷光有机电致发光器件(OLED),研究了不 同掺杂量对蓝绿色磷光OLED器件发光特性的影 响。制得器件的结构为ITO/MoO₃(20nm)/NPB(40nm)/mCP:BGIr1(x%,30nm)/BCP(10nm)/Alq₃(20 nm)/LiF/Al(100nm),其中x%为发光层中磷光染料BGIr1的掺杂量(质量分数)。结果表明,BGIr1掺杂量 为18%时,获得器件的发光性能最佳。18% BGIr 1掺杂器件在488nm和 512nm处获得两个主发射峰,当电 流密度为26.5mA/cm²时,获得最大发光效率为6.2cd/A;在15V驱动电压下,获得最大亮度为6970cd/cm², CIE坐标为(0.17,0.31)。这说明,BGI r1掺杂改善了器件的发光亮度和色纯度,提高了器件的发光效率。     

具有缓变结的蓝色有机电致发光器件

针对通常的突变异质结(HJ)结构的蓝色有机发光器件(OLED)稳定性差这一难题,制备了一种具有缓变结(GJ)的蓝色OLED,在空穴传输层(HTL)和发光层(EML)间构成GJ.与常规的HJ OLED相比,具有GJ器件的稳定性明显提高.在初始亮度为100 cd/m2时半寿命达到6998 h,是一般HJ器件的6倍.这主要是因为削弱了突变HJ产生的局部高电场,减少了产生的焦耳热,从而提高了器件的稳定性.但是,GJ器件效率相比HJ没有提高.因为GJ增大了空穴注入,空穴是多数载流子,这样不利于载流子的平衡.为了补偿效率损失,在TBADN/Alq界面上插入Gaq薄膜.由于Gaq的LUMO能级在Alq和TBADN的LUMO能级间,形成了从Alq经Gaq到TBADN的势垒阶梯,提高了电子注入,进而提高了器件效率.这种GJ Gaq器件的效率比一般GJ器件提高20%,寿命是HJ器件的7倍.     

基于N-BDAVBi的高效率双发光层蓝色OLED

采用蓝色有机荧光染料N-BDAVBi作为客体发光材 料,将其分别掺入主体材料ADN和DPVBi中形成双发光层,制备了结构为ITO/m-MTDATA(40nm)/NPB(10nm)/ADN:N-BDAVBi(15nm)/DPVBi:N-BDAVBi(15nm)/TPBi(30nm)/LiF(0.6nm)/Al的高效率蓝色有机荧光器件(OLED)。器件的最大电流效 率为8.13cd/A,对应色坐标为(0.178,0.302) ,电流密度为18.81mA/cm²,分别是ADN:N-BDAVBi和DPVBi: N-BDAVBi作为发光层的单发光层结构器件的2.4和1.8倍。器件性能 提高主要源于双发光层结构减弱了 载流子在界面处的积累,扩大了激子产生区域以及主体与客体之间有效的能量 转移。当驱动 电压为14V时,双发光层器件的最大亮度为20620cd/m²。     

蓝光OLED的掺杂研究

采用蓝色发光材料ADN为主体发光材料、BAlq3为掺杂材料,通过改变BAlq3的掺杂浓度制备了结构为ITO/NPB/ADN:BAlq3/Alq3/Mg:Ag的一系列蓝光有机发光器件(OLED).研究了器件各有机层之间的能级匹配和BAlq3的掺杂浓度对载流子注入、传输、复合以及发光色纯度的影响.实验结果表明,空穴阻挡材料BAlq3的掺入显著影响OLED的电流密度、发光亮度、发光效率和发光光谱,当BAlq3的掺杂浓度为25%时,OLED的发光效率为1.0 lm/W,发光光谱的峰值为440 nm,色纯度为(0.18,0.15),未封装器件的半衰期为950小时,器件同时满足了高效率和高色纯度的要求.     

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.