场致发射显示器的现状与发展

通过对场致发射显示器（FED）发展现状及其应用前景进行系统的比较与分析，着重讨论了场致发射体与其阵列制备工艺以及各种关键技术的优缺点，并介绍国外著名公司的研究动态，展望FED的发展趋势。     

All‐Carbon Nanotube‐Based Flexible Field‐Emission Devices: From Cathode to Anode

The fabrication of a flexible field‐emission device (FED) using single‐walled carbon nanotube (SWNT) network films as the conducting electrodes (anode and cathode) and thin multi‐walled CNT/TEOS hybrid films as the emitters is reported. P‐type doping with gold ions and passivation with tetraethylorthosilicate (TEOS) made the SWNT network film highly conductive and environmentally stable, and hence a good alternative to conventional indium tin oxide electrodes. CNT/TEOS hybrid emitters showed high current density, low turn‐on field, and long‐term emission stability, compared with CNT emitters; these characteristics can be attributed to the TEOS sol, acting both as a protective layer surrounding the nanotube tip, and as an adhesive layer enhancing the nanotube adhesion to the substrate. All‐CNT‐based flexible FEDs fabricated by this approach showed high flexibility in field emission characteristics and extremely bright electron emission patterns.     

Integration and characterization of amorphous silicon thin-filmtransistor and Mo-tips for active-matrix cathodes

We have designed and monolithically integrated amorphous silicon thin-film transistor (a-Si TFT) with Mo-tip field emitter arrays (FEAs) on glass substrate for active-matrix cathodes (AMCs) in field-emission display (FED) application. In our AMCs, a light shield layer of metal was introduced to reduce the photo leakage and back channel currents of a-Si TFT. The light shield was designed to have the role of focusing grid to focus emitted electron beams from the AMC on the corresponding anode pixel by forming it around the Mo-tip FEAs as well as above the a-Si TFT. The thin film depositions in a-Si TFTs were performed at a high temperature of above 360°C to guarantee the postvacuum packaging process of cathode and anode plates in FED. Also, a novel wet etching process was developed for n⁺-doped-a-Si etching with high etch selectivity to intrinsic a-Si and good etch controllability and was used in the fabrication of inverted stagger TFT with a very thin active layer. The developed a-Si TFTs had good enough performance to be used as control devices for AMCs with Mo-tip emitters. The fabricated AMCs exhibited very effective aging process for field emitters     

碳纳米管冷阴极材料制备及其场发射性能研究

在场发射显示器技术领域,碳纳米管被认为是目前最有前途的场发射冷阴极材料之一。碳纳米管具有低的场发射阈值电场,高的发射电流密度使它们比传统的热阴极材料以及其他的场发射冷阴极材料更适于实际的技术应用。介绍了碳纳米管的制备方法和场发射原理,并对碳纳米管的场发射性能研究进行了综合的评述。     

应用于LCD的平栅型碳纳米管场致发射显示器背光源的研制

采用磁控溅射、光刻和湿法刻蚀技术制备平栅型场发射阴极阵列,利用电泳将碳纳米管(CNT)发射源沉积在阴极表面,将阴极板和阳极板封接后制成51cm单色平栅型CNT场致发射显示器(CNT-FED),作为背光源模板应用于49 cm液晶显示器(LCD)器件中.场发射测试表明,器件在阳极电压3 500V、栅极电压290 V时,阳极...     

Fabrication of field emission display prototype utilizing printed carbon nanotubes/nanofibers emitters

Carbon nanotubes/nanofibers (CNTs) used as emitters, diode-type field emission display (FED) prototypes of dot matrix and character images were fabricated by low-cost techniques and equipments, respectively. The technical development in the design and fabrication of the cathode, the anode, and the panel, is described. CNTs were produced by a simple, low-cost and easily-controllable thermal chemical vapor deposition. The cathode was prepared by the screen-printing method. The field emission characteristics were enhanced by a heat post-treatment in H₂ gas atmosphere. The panel structure was packaged by a vacuum fluorescent display-like process and vacuum-sealed through an exhaust glass tube. The fully-sealed CNTs FED (c-FED) showed good emission properties. The brightness of 600 cd/m² was achieved from the yellow phosphor at a relatively low applied electric field. The developed technology has a potential practical application in c-FED.     

场致发射平板显示器的研究进展

利用碳纳米管作为阴极材料的场致发射显示器是一种新型的平板真空器件。介绍了二极管型和三极管型场致发射显示器的各种基本结构,给出了场致发射平板显示器的基本行列矩阵寻址方式原理,重点分析和讨论了在制作大面积平板器件方面所存在的支撑结构问题,这种新颖的平板显示技术将会进一步降低生产成本和提高显示质量。     

基于探针法的FED电极缺陷检测系统设计

针对FED显示屏电极的特征,提出一种FED电极缺陷检测系统,用于检测FED电极的短路和断路等缺陷。系统分为硬件和软件两部分,硬件部分由CCD摄像头初始定位和对准模块、单片机数据测试和传输模块、计算机数据接收和处理模块组成;软件部分包括单片机预处理部分的底层程序设计和计算机部分面向对象的高级程序设计。经过硬件设计安装和软件编程调试,该FED电极缺陷检测系统已经在实验中得到应用。     

Spacer visibility problem in field emission displays due to surface contamination

Spacer visibility is a critical issue in field emission displays (FEDs). Many reasons can lead to visible spacers, such as charging due to secondary electron emission under electron bombardment. In this paper, we will present results on spacer visibility due to chemical contamination on the spacer surface. We have identified Na contamination as the cause for the white spacer problem observed in the early developing stage of FED. The diffusion of Na from spacers to its adjacent cathode area during field emission operation caused higher field emission current from those field emitters. We believe the higher emission is due to the temporary gettering effect from the Na species, which cleaned the local field emitters. We have also found the existence of Pb on the spacer surface could create the dark spacer problem. To avoid any spacer visibility problem, the spacer surface must be kept clean. Any post clean procedure used to clean the surface should not leave any trace of elements such as Na, or Pb.     

Improved luminance of moving picture in field emission displayoperating with microchannel plate

A specially fabricated microchannel plate (MCP) has been successfully applied to a field emission display (FED) to obtain a bright moving picture, where the FED is operated by line-by-line addressing in the driving circuit. The anode brightness is about three times higher with an MCP, which also shows current stability     

LVDS技术在彩色FED中的应用

介绍了LVDS的特点以及FED主板信号的传输,重点论述了DS90CF383A/384A芯片的结构、工作时序以及在FED平板显示器件中的应用,提出了基于DS90CF383A/384A的硬件电路设计方案。此接口电路方案已经在25英寸彩色FED驱动系统中使用,并且消除了在信号传输过程中受到的干扰,提高了图像质量。     

场发射显示器(FED)荧光粉的研究进展

场发射显示器(FED)是一种新发展起来的平板显示器。它在亮度、视角、响应时间、工作温度范围、能耗等方面具有优良的特性。文章首先简要地介绍了FED发展历史和现状、工作原理以及对荧光粉的要求，然后介绍了FED荧光粉的研究历史和发展现状以及有关FED荧光粉激发和发光机理的相关研究工作。最后就FED荧光粉的研究提出了一些建议。     

Fitted Elmore delay: a simple and accurate interconnect delay model

In this brief, we present a new interconnect delay model called fitted Elmore delay (FED). FED is generated by approximating HSPICE delay data using a curve fitting technique. The functional form used in curve fitting is derived based on the Elmore delay (ED) model. Thus, our model has all the advantages of the ED model. It has a closed-form expression as simple as the ED model and is extremely efficient to compute. Interconnect optimization with respect to design parameters can also be done as easily as in the ED model. In fact, most previous algorithms and programs based on ED model can use our model without much change. Most importantly, FED is significantly more accurate than the ED model. The maximum error in delay estimation is at most 2% for our model, compared to 8.5% for the scaled ED model. The average error is less than 0.8%. We also show that FED can be more than 10 times more accurate than the ED model when applied to wire sizing.     

Realization of exceeding 80% external quantum efficiency in organic light-emitting diodes using high-index substrates and highly horizontal emitters

Although both high-index substrates and horizontal-dipole emitters have been shown to be facile approaches for enhancing OLED (organic light emitting diode) light extraction, the full benefits and potential of their combination for OLED optical out-coupling have not been thoroughly studied and explored. Simulation studies indicate that very high optical coupling efficiency into substrates ϕ_sub (and perhaps similarly high OLED external quantum efficiencies) of ~90% can be possibly obtained with both high-index substrates (refractive index >1.8–1.9) and highly horizontal-dipole emitters (horizontal dipole ratio >85%), together with adoption of low-index or index-matching carrier transport layers and optimization of organic layer and transparent electrode thicknesses. With these judicious device design conditions, all waveguided modes and surface plasmon modes in devices can be effectively suppressed for optimal optical out-coupling. Finally, combining the sapphire substrate having high index of n~1.78, the recently developed OLED emitters having high horizontal emitting dipole ratio of up to 87%, and simple external extraction lens, OLED devices having external quantum efficiency of over 80% was successfully realized.     

Superbeta polysilicon emitter transistors

In-situ phosphorus-doped polysilicon emitters deposited on monocrystalline silicon substrates at a temperature of 627°C and subjected to no additional high-temperature annealing are shown to be capable of giving Gummel numbers GEin excess of 10¹⁵scm^-4. Polysilicon emitters formed in this way have been used to produce superbeta transistors with performance comparable to the record levels recently reported for MIS emitter devices. In particular, common-emitter current gains β in excess of 30000 have been obtained at low VCBvalues.     

Identification of humans using gait

We propose a view-based approach to recognize humans from their gait. Two different image features have been considered: the width of the outer contour of the binarized silhouette of the walking person and the entire binary silhouette itself. To obtain the observation vector from the image features, we employ two different methods. In the first method, referred to as the indirect approach, the high-dimensional image feature is transformed to a lower dimensional space by generating what we call the frame to exemplar (FED) distance. The FED vector captures both structural and dynamic traits of each individual. For compact and effective gait representation and recognition, the gait information in the FED vector sequences is captured in a hidden Markov model (HMM). In the second method, referred to as the direct approach, we work with the feature vector directly (as opposed to computing the FED) and train an HMM. We estimate the HMM parameters (specifically the observation probability B) based on the distance between the exemplars and the image features. In this way, we avoid learning high-dimensional probability density functions. The statistical nature of the HMM lends overall robustness to representation and recognition. The performance of the methods is illustrated using several databases.     

1995年真空微电子学的进展评述

真空微电子学是９０年代国外迅速发展的一门新学科，本文综述了１９９５年的新进展。在场致发射阴极方面研究工作向深度和结合实际应用发展，研究工作十分活跃。Ｍｏ和Ｓｉ－ＦＥＡ都取得了新的进展。在微波管方面的应用，１０ＧＨｚ的速调四极管已在总装，技术上取得了突破性进展。美国和法国已建立数个ＦＥＤ的生产工厂，产品正走向市场。     

SiI161在彩色FED中的应用

简单介绍了数字视频接口DVI 1.0接口规范,着重论述了SiI161芯片内部功能结构、工作时序以及在FED平板显示器件视频驱动电路中的应用。提出了基于SiI161的硬件电路设计方案,此电路方案已在25英寸彩色FED驱动系统中使用,为系统提供优质的数字视频源,显示分辨率最高支持UXGA。     

FED器件的支撑结构设计和实现

使用墙式结构作为FED器件的内的支撑，使用Algor专用力学有限元件对器件各种结构的力学特性进行了数值计算，同时对照器件的电学特性后确定了支撑墙的分布密度，安装位置和装配误差等工艺参数，并完成了现有器件条件下的工艺实现，得到理想的结果。     

Enhance external quantum efficiency of organic light-emitting devices using thin transparent electrodes

High-index transparent electrodes have been one major origin of light trapping and lower light extraction in organic light emitting diodes (OLEDs). In this work, influences of the bottom transparent electrode thickness on emission properties of OLEDs are systematically studied by both simulation and experiments. Simulation shows that with substantially decreasing the thickness of the high-index indium tin oxide (ITO) electrode, waveguided modes, that otherwise would be significantly induced in regular/thicker ITO devices, can be effectively eliminated. Consequently, the overall coupling efficiencies of OLED emission into substrates can be much enhanced. Through further effective light extraction from the substrate, green phosphorescent OLEDs with a high external quantum efficiency (EQE) of up to ≈57.5% were experimentally demonstrated by adopting the very thin (20 nm) ITO electrode and preferentially horizontal dipole emitters (with a horizontal dipole ratio of 76%). The simulation further predicts that very high optical coupling efficiencies into substrates and EQEs approaching 80% are possible with further adopting purely horizontal dipole emitters and/or low-index electron transport layer (ETL) to suppress surface plasmon modes. Overall, this study clearly reveals the potential of using thin transparent electrodes for highly efficient OLEDs.