新型荫罩式PDP放电单元谐振光子辐射和捕获过程研究

本文在流体模型计算的基础上采用蒙特卡罗模型,研究了彩色等离子体平板放电单元中的辐射和捕获过程.研究了新型荫罩式等离子体显示器(SMPDP)和传统的交流表面放电等离子体显示器(ACC PDP)的放电过程以及谐振光子的辐射和捕获特性.给出了电子及氙谐振态平均浓度以及相应空间浓度分布随时间变化情况.模拟了谐振光子和147谱线的分布情况.可以看到SMPDP的发光效率高于表面放电结构.     

真空电子技术

O4612007060213共面介质阻挡放电特性研究/欧阳吉庭,何锋,缪劲松,冯硕(北京理工大学理学院)//物理学报.―2006,55(11).―5969～5974.对共面介质阻挡放电(DBD)的放电过程进行了实验和理论研究。在实验中设计了分段电极方法来获取放电过程中不同位置上的局域电流和光辐射特性,得到了阴极上等离子体的扩展速度,并与二维流体数值模拟结果进行了比较。结果表明,在共面DBD的暂态放电过程中,电极上空等离子体区域始终存在有不均匀电场,导致了不同位置上放电电流和光辐射分布的不一致。同时研究还表明,在DBD放电过程中应当考虑表面光致二次电子…     

对向型等离子体显示板放电特性分析

采用流体模型分析了对向型交流等离子体显示板(ACM PDP)的放电过程.通过模拟,获得了ACM PDP单元的Q-U曲线及电压转移曲线,同时还给出了放电延迟、电流脉冲宽度与放电电压的关系,所得结果符合实验测量数据.     

CO2激光诱导大气放电特性的研究

为了研究脉冲CO₂激光诱导空气放电的特性,建立了高压电容充放电实验平台,采用间距为8mm、半径为10mm的一对球形石墨电极,取得了放电电压和电流的实时数据,采用2阶振荡电路模型对放电电压和放电电流进行拟合得到了电极间激光诱导放电等离子体的阻抗,并对放电时间、放电延时及抖动做了统计。结果表明,激光诱导放电等离子体的阻抗很小,约1Ω~2Ω,拟合得到的放电等离子体阻抗随放电电压、放电电容、以及激光能量的增加而减小;放电延时随着实验条件的变化在2μs~10μs之间变化,放电延时以及延时抖动随着放电电压和激光能量的增加而降低,而受放电电容大小的影响不明显。由此高稳定性的激光脉冲和高压有助于激光诱导放电过程的稳定。     

基于荫罩式PDP新型十字扫描电极放大单元的研究

新型荫罩式等离子体显示板利用制造工艺成熟的金属荫罩替代复杂的介质障壁,不仅降低了成本、而且改善了性能.为了进一步提高其亮度和效率,针对42 inch荫罩式等离子显示器提出了一种新型十字形扫描电极结构,采用放大单元实验方法,研究了该电极结构的放电过程,给出了高速ICCD拍摄的光分布图.测量了相应的功耗、红外辐射强度、以及放电效率,并与传统条状电极结构进行了比较.结果表明,新型十字形扫描电极结构使放电区域沿扫描电极的主电极部分大大扩展,放电更剧烈,亮度也有显著提高,效率得到了改善,放电速度也更快.     

彩色PDP发光效率的分析及改善方法

分析了影响等离子体显示器(PDP)发光效率的因素,在此基础上, 介绍了提高PDP发光效率的四种措施:选择10%Xe,使用新型的单元结构,利用正柱区放电以及外加射频电压.     

基于二维PIC-DSMC的微间隙气体放电等离子体演化过程研究

准确的理解微间隙气体放电中非平衡等离子随时间的演化过程对于设计气体开关、微电子及其它等离子体器件有着非常大的帮助。通过二维PIC-DSMC耦合算法模拟了一个大气压氮气环境下微间隙平板电极发生气体放电时电子及离子的运动演化过程,得到了气体放电过程中平板电极间电子和离子数密度分布随时间变化的趋势,讨论了阳极附近电子云的形成与演变、阴极附近存在的鞘层以及电子和离子的速度及温度分布,最后将模拟计算得到的击穿电压与帕邢曲线及相关实验结果进行了对比,为相关等离子体器件的进一步发展提供了理论基础。     

固体膜外电极型LCD平板背光源

为了进一步提高内部无电极型LCD平板背光源的发光亮度及其使用寿命,制备了一种利用固体IT0导电薄膜为导电介质的等离子体激发发光平板背光源.该电光源由两片平板玻璃中间充入纯氙气密封而成,光源内表面上各涂敷一层荧光粉,在玻璃板的外表面上用透明导电胶粘上一层ITO(氧化铟锡)导电薄膜为导电介质,以1.1 mm厚的玻璃板作为介质阻挡放电层,在高频交变电压的作用下产生等离子体,激发荧光粉发光.其最大发光亮度可达4 500 ed/m2,可持续发光5 000 h,最佳激发频率10.0 kHz,发光均匀度大于92%.     

低频交流外电极放电着火特性的研究

在有电介质隔离时,放电气体与激励电极之间的气体放电现象称为外电极放电,它必须用交流电激励.一旦放电后,在放电空间内形成等离子体.激励电极大多采用平面电极.我们研究了频率为50Hz的低频外电极放电的着火特性.     

CO2激光诱导空气等离子体放电通道特性研究

为了研究高能脉冲CO₂激光诱导空气等离子体放电通道的特性,建立了高压电容充放电实验平台,激光束经离轴抛物聚焦镜汇聚,引发间距可调的盘状电极和针状电极之间的等离子体放电通道。利用电气参量测量、发射光谱测量等手段,分析了等离子体放电通道的启动特性、阻抗特性和等离子体密度。结果表明,激光束与放电方向同轴的结构以及较大的脉冲能量,使得激光诱导等离子体放电通道的启动时间大幅缩短,50mm间距的等离子体通道,启动时间约为2μs;激光诱导等离子体放电通道的阻抗很小,约1Ω~2Ω,并且阻抗值随放电电压的增加有减小的趋势,而与等离子体通道长度的关系不明显;由谱线的Stark展宽计算获得的空气击穿之后、放电启动之前的等离子体电子密度约为1019cm-3,尽管放电启动时等离子体辐射显著增强,但等离子体密度近乎单调下降。这些结果将有利于高能脉冲CO₂激光诱导空气等离子体放电通道的应用研究。     

A New AC Plasma Display Panel With Auxiliary Electrode for High Luminous Efficacy

A new ac plasma display panel (PDP) for high luminous efficacy is proposed, and its characteristics are investigated. The new ac PDP has a coplanar gap of 200 mum and an auxiliary electrode located between the scan and common electrodes. The periodic pulses are applied to the auxiliary electrode during the sustain period, which plays the roles of enhancing the infrared emission and reducing the discharge current. The sustain voltage decreases with the increase of the auxiliary pulse voltage until 80 V. When the voltage of the pulse applied to the auxiliary electrode is 50 V, the luminous efficacy reaches its peak value and is approximately 8.7 lm/W obtained from the measurement of Ne + 20% Xe gas-mixture discharges in the green cells. The luminous efficacy of the new proposed test ac PDP with Ne + 13% Xe and Ne + 20% Xe gas mixtures is improved by 190% and 320%, respectively, compared to that of the conventional ac PDP with a Ne + 13% Xe gas mixture     

A measurement of very fast transition durations due to gapdischarge in air using distributed constant line system

Very fast transition durations (rising time in positive polarity and falling time in negative polarity) due to starting of gap discharge were investigated in time domain. The gap space was set very small for voltages below 1500 V as a simulation of the charged device model (CDM) electrostatic discharge (ESD) and the gap discharge of switch devices. The measurement system consists of a distributed constant line system with a tapered coaxial electrode, which has a matched impedance for the characteristic impedance of the distributed constant line system. The insertion loss of the tapered coaxial electrode was within -3 dB in the frequency range below 4.5 GHz. The atmosphere around the electrode is ordinary air. This experimental system enables one to measure the high-speed transients of about 100 ps due to gap discharge in time domain. As a consequence of the experiment, the relationship between the discharge voltage and transition duration was confirmed. The voltage rise time was slowed down gradually in positive polarity, while the voltage fall time was slowed down remarkably in negative polarity for the 0.1-mm needle     

具有碳纳米管掺杂的场增强型DBD平面光源性能研究

为了降低介质阻挡放电平面光源(DBDL)器件的着火电压以及提高其发光效率,本文提出了一种掺杂型的具有场增强型结构的DBD平面光源,该结构采用碳纳米管(CNT)与荧光粉相混合,在荧光粉表明镀有一层厚度为40 nm的MgO薄膜以提高二次电子发射系数及降低气体放电中产生的离子对CNT的冲击.实验结果表明采用在荧光粉中掺杂CNT以及蒸镀MgO薄膜的DBD平面光源结构可以有效降低器件的着火电压和提高发光效率,同传统无掺杂的结构相比,在气压为50kPa的Ne-15％Xe混合气体时,掺杂比为1 ∶ 5000的DBD平面光源其着火电压降低了10％;在相同输入功率下,其亮度及发光效率提高了约20％.     

New Sustain Waveform for Improving Luminous Efficiency in Wide-Gap Plasma-Display Panel

The three-electrode microdischarge characteristics of ac-plasma-display panels (PDPs) are analyzed with a wide sustain discharge gap of 180 mum. In particular, the luminous efficiency variation is examined as a parameter of the operating frequency. It is found that the luminous efficiency decreases with an increase in the operating frequency. In other words, a failure discharge mode for luminous efficiency occurs at a high frequency up to 200 kHz, originating from a self-erasing discharge and the space-charge behavior under high sustaining frequency conditions. Thus, based on an analysis of the failure mode of a wide-gap discharge, a new sustain waveform is proposed to improve the luminous efficiency at a high operating frequency. As a result of adopting the proposed sustain waveform, a luminous efficiency of 2.4 lm/W is obtained at a sustain voltage of 170 V in a 42-in high-definition wide-gap PDP.     

AC Microplasma Device With a Cylindrical Hollow Electrode for Improving Luminous Efficacy

In this paper, a device utilizing the hollow cathode discharge is demonstrated to diagnose the possibility of improving luminous efficacy of a microplasma device. A series of experiments is conducted by measuring luminous efficacy, which is an important factor in display devices, in accordance with specifications of the cylindrical hollow and gas pressure. The proposed structure has two electrodes, and one of them contained a cylindrical hole and is called a hollow electrode. The hollow electrode works as either a cathode or an anode alternately due to the ac operating conditions. When the hollow electrode operated as a cathode, the luminous efficacy is higher than that of the anode case, and this tendency is observed consistently throughout all experiments. Moreover, from the measurement results on the tendency of luminous efficacy in terms of hole specifications, different aspects of luminous efficacy are obtained, depending on whether the variation is in the diameter or in the depth. In case of the diameter, the luminous efficacy is improved when $p cdot D$ (i.e., the product of the gas pressure and the diameter of the cylindrical hole) is less than one $hbox{Torr} cdot hbox{cm}$. In the case of the depth, the maximum value of luminous efficacy exists at the certain $p cdot d$ (i.e., the product of the gas pressure and the depth of the cylindrical hole).      

PDP介质保护膜材料的研究进展

由于AC PDP介质保护膜与放电气体直接接触,因而对PDP的工作特性如工作寿命、发光效率、发光亮度、着火电压及放电时间延迟等有重要影响,其性能的提升对提高AC PDP的工作特性有重要意义。本文综述了介质保护膜材料的最新发展状况,包括五种掺杂MgO保护膜和两种新型材料的介质保护膜,并将其发光效率、发光亮度、维持电压、记忆系数等工作特性同传统MgO保护膜进行了对比、分析。     

The Operation Characteristics of an Alternating Current Plasma Display Panel With Si-Doped MgO Protecting Layer

In this paper, the operation characteristics of an ac plasma display panel (PDP) with Si-doped MgO protecting layer are investigated. The test panels are fabricated with the protecting layers of conventional MgO and Si-doped MgO, and the operation voltage margin, luminous efficacy, and address discharge time lag are observed. Even though the test panel with Si-doped MgO protecting layer showed lower operation voltages, higher luminous efficacy, and shorter statistical discharge time lag, its addressing discharge characteristics become deteriorated as the scanning time is increased from the end time of the reset period. The photon-induced surface conductivity increased by Si doping into MgO, and surface charges on the Si-doped MgO protecting layer showed faster decay characteristics compared to those on the conventional one. It is believed that the impurity doping into the protecting layer can improve the short-period characteristics of an ac PDP, but the long-term stability of surface charge retention is deteriorated.     

Principles and techniques in multicolor DC gas discharge displays

Some aspects of the gas discharges in multicolor displays are discussed. The different techniques for generating visible radiation are mentioned. It is shown that the intrinsic luminous efficiency of a gas discharge is greatly reduced in real display panels by virtue of a number of factors, which are calculated. It appears that the positive column discharge in a gas mixture of argon and mercury vapor gives the highest luminous efficiency. Means of improving the luminous efficiency are indicated. A display with positive column discharges, as used in experiments, is described. The voltage and light output of a pulsed discharge are discussed.     

用于横向放电气体激光器的多通道开关

研制了用于横向放电气体激光器的多通道开关,研究了触发电压特性、触发电极结构对通道开关特性的影响,得到了每米29个通道的结果.