无机电致发光的新进展及机理分析

主要介绍了分层优化结构、蓝源成彩技术（color—by—blue）及无机薄膜电致发光中的一些物理问题。在分层优化结构中采用了极性材料SiO2作为电子加速层，可以将过热电子的最大能量提到10eV左右，增加了可以激发发光中心的过热电子数目，是提高无机薄膜电致发光效率的唯一的方法。蓝源成彩技术（color—by—blue）是两种激发方式的混合——电致发光和光致发光，利用BaAl2S4：Eu材料中获得的高亮度（900cd／m^2）的蓝色电致发光激发绿色及红色光致发光材料，获得了色纯度非常高的三基色发光，实现了无机彩色电致发光。目前以蓝源成彩技术为基础的17英寸彩色电视机样机已经问世，这种电视机的最大亮度可以到600cd／cm^2，对比度达到1000：1．     

无机电致发光的新进展及机理分析

主要介绍了分层优化结构、蓝源成彩技术(color-by-blue)及无机薄膜电致发光中的一些物理问题。在分层优化结构中采用了极性材料SiO2作为电子加速层,可以将过热电子的最大能量提到10 eV左右,增加了可以激发发光中心的过热电子数目,是提高无机薄膜电致发光效率的唯一的方法。蓝源成彩技术(color-by-blue) 是两种激发方式的混合——电致发光和光致发光,利用BaAl2S4:Eu材料中获得的高亮度(900 cd／m2)的蓝色电致发光激发绿色及红色光致发光材料,获得了色纯度非常高的三基色发光,实现了无机彩色电致发光。目前以蓝源成彩技术为基础的17英寸彩色电视机样机已经问世,这种电视机的最大亮度可以到600 cd／cm2,对比度达到 1000:1。     

采用CaS_1-xSex:Eu发光层红色EL器件的特性

引言为实现高质量全色显示,使用稀土掺杂的碱土硫化物作为发光层的薄膜EL器件一直是大量研究工作的主要课题。Eu掺杂的CaS作为高亮度红色EL荧光体一直为人们所关注,它可以取代常规的ZnS:Sm红色荧光体。本文论述了使用新开发的CaS_(1-x)Se_x:Eu发光层的发射红光EL器件,这种发光     

有机EL与无机EL和LCD的比较及其未来前景

通过比较有机EL与无机EL、LCD在平板显示应用方面的差异，展示了OELD的美好应用前景。由于无机薄膜EL缺乏高亮度蓝基色成分以及驱动电压是100V左右的交流，难于制成低压彩色超薄显示器；无机分散型EL屏采用的是十几微米厚的粉末材料，也难于制成高分辩率超薄显示器，因此它们都无法与OELD相比。OELD显示器体积可以是LCD的1/2，功耗也大低于LCD，所以OELD将有望取代LCD。评述了当前OELD的最新发展趋势：采用荧光染料掺杂式的模糊界面结构的电致荧光器件和采用荧光染料掺杂式的电致磷光器件是当前OELD发展的主要潮流。文中还评述了采用低折射率材料提高外量子效率的情况。     

蓝色发光有机电致发光器件

具有多层薄膜结构,发射鲜蓝色光的有机电致发光(EL)器件已经制成并为选择蓝色发光材料制定了二个经验性指南。要获到具有高 EL 效率的 EL 器件,关键是发射层要有优异的成膜能力以及发射极与载流子输运材料的适当组合,避免形成激态复合物。在我们的有机电致发光器件中,有一个器件在电流密度为100mA/cm~2,直流驱动电压为10V 时,蓝光发射亮度达700cd/m~2。     

采用薄膜滤光片的高亮度红色发光EL器件

最近研制出一种使用硫硒化镉材料的带边吸收薄膜滤光片,它与ZnS:Mn配合使用可得到明亮的红色EL。亮度和色度取决出S/Se比和薄膜厚度。以60Hz、高于阈值30V的电压驱动,器件的亮度达20fL,色度值为x=0.65,y=0.35。可以把无机滤光片与荧光粉薄膜一起制备在衬底上,得到明     

电子束共蒸发Al2O3-La2O3和ZrO2-Ta2O5复合薄膜的介电性能研究

Al2O3、ZrO2、Ta2O5和La2O3薄膜在栅介质、无机EL介质和光学薄膜方面有着重要用途,但对其复合薄膜介电性能方面的研究很少。文章采用电子束共蒸发法制备了厚度分别为414nm和143nm的Al2O3-La2O3（ALO）和ZrO2-Ta2O5（ZTO）复合薄膜,用Sawyer—Tower电路测得介电常数分别为17和34,反映介电损耗的参数△Vy分别为0．013V和0．56V,击穿场强分别为128MV／m和175MV／m,在50MV／m场强下,ALO的正、反向漏电流密度分别为3．1×10-5／cm2和4．1×10-5A／cm2,ZTO的正、反向漏电流密度分别为3．9×10-5／cm2和3．7×10-5A／cm2。另外,实验还与电子束蒸发和反应溅射制备的Al2O3、ZrO2、Ta2O5的介电性能做了比较,结果表明,上述复合薄膜单独作为无机EL绝缘层是不合适的。     

无机电致发光平板显示技术研究进展

无机电致发光（EL）平板显示是一项有着广泛应用前景的自发光型平板显示技术。本文简单介绍了无机EL平板显示器的结构、原理和实现全彩色显示的方法，阐述了所使用的电极、介质和发光材料的作用、要求及研究现状，分析了存在的问题，并展望了其产业化的前景。     

无机EL显示技术研究和开发进展

无机电致发光平板显示是重要的平板显示技术之一.总结了最近几年国际上无机EL领域理论研究和产品开发方面的研究进展,分析了当前无机EL产业状况、国内外存在巨大技术差距以及国内一些单位在产业化方面的努力相继失败的原因,指出了无机EL领域一些重要的科学与技术问题,并提出自己的看法.     

基于有机-无机异质结的白色电致发光器件

制备了一种白色有机-无机异质结ITO／Poly(9,9-bis(2-ethylhexyl))fluorine(PFs)／ZnS：Mn／Al电致发光(EL)器件。其EL光谱是一个宽的发光带,范围从410nm到650nm。通过对器件的EL、光致发光(PL)、瞬态EL以及EL发光强度随电压和电流的变化关系等的研究,认为其EL来源于PFs和ZnS：Mn各自的发光叠加,其中PFs的发光机理是电子和空穴的复合发光,而ZnS：Mn的发光机理是过热电子的直接碰撞激发发光。器件的起亮电压约7V,最大发光亮度约62．1cd／m^2,色坐标为：X-0．303,Y=0．32。结果表明,有机-无机异质结是一种实现白光EL的新途径。     

阻挡层结构的蓝色有机发光二极管

制备了ITO／CuPc/NPB/TPBi/Alq3/MgAg有机发光二极 管,由于阻挡层TPBi对空穴的阻挡作用,器件的电致发光为NPB特征光谱,实现了蓝色发光。器件最大亮度和最大流明效率分别为3700cd/cm^2和0.78 lm/W,CIE色坐标为x=0.110 ,y=0.085,色度纯正。然而器件显现出较差的稳定。利用器件的能级结构,分析了器件的光学特性和影响稳定性的因素。     

High brightness ZnS and GaN electroluminescent devices using PZT thick dielectric layers

An improved thick dielectric (TD) layer for inorganic electroluminescent (EL) display devices has been achieved through a composite high-/spl kappa/ dielectric sol-gel/powder route. This composite TD film results in a luminance improvement (up to 10/spl times/) in these TDEL devices with Eu-doped GaN and Mn-doped ZnS phosphor layers. The use of a composite TD film, composed primarily of lead-zirconate-titanate (PZT), results in a significantly higher charge (>3 /spl mu/C/cm/sup 2/) coupling to the phosphor layer. Furthermore, the reduction in porosity of the TD has improved the homogeneity of electric field applied to the phosphor layer, resulting in a steeper luminance-voltage slope. The reduction in porosity has also decreased the diffuse reflection of the TD, which when pigmented, exhibits a diffuse reflectivity of <2% resulting in high display contrast. High luminance levels of up to 3500 cd/m/sup 2/ have been achieved from the ZnS:Mn TDEL devices and 450 cd/m/sup 2/ from GaN:Eu devices. A detailed analysis of the electrical steady-state time-varying characteristics has shown that the electrical performance of TDELs is very similar to TFELs in spite of the physical asymmetry in the device structure. These results demonstrate that three critical requirements for practicality of the TDEL approach (formation on standard display glass, low reflectivity, and electric field homogeneity) can be obtained by careful selection and design of the device materials, fabrication process and device structure.     

Blue electroluminescent devices withSrGa2S4:Ce for full-color display

In order to realize full-color electroluminescent (EL) displays, which are expected as a dominant candidate for the future multimedia flat panel display, blue EL devices with SrGa₂S₄:Ce have been prepared by molecular beam epitaxy (MBE). This paper proposes a novel deposition method employing Sr metal and Ga₂S₄ compound as the source materials. A single-phase SrGa₂S₄ layer is obtained in a Ga₂S₃/Sr flux ratio of 60 and at the growth temperature of 560°C. We have obtained the well-saturated blue with CIE color coordinates of x=0.14, y=0.14 and brighter blue EL devices made by optimizing the growth conditions in MBE. The maximum luminance of 70 cd/m² in comparison with the 3 cd/m₂ of our previous EL devices, is achieved at a driving frequency of 1 kHz     

用于PDP的蓝色荧光粉的最新发展

作为一种发蓝光的荧光粉，只有BaMgAl10O17：Eu^2＋（BAM）被实际用于等离子体显示屏（PDP）。然而，BAM在显示屏制造和工作期间发生严重恶化，会导致发光效率和色纯度下降。本文回顾对BAM老化机理的研究。另外，讨论了用于等离子体显示屏的BAM改进和作为BAM替代物的新的蓝色荧光粉的现状。     

The development of chelate metal complexes as an organicelectroluminescent material

The chelate metal complexes, such as tris(8-hydroxyquinolinate)aluminum (Alq₃), have excellent electroluminescent (EL) properties. Several chelate metal complexes were developed and the experimental rule of molecular design for use in an organic EL device was found. When the chelate metal complex has the structure of an inner complex sell, the EL device is fabricated by conventional vacuum-vapor deposition. This rule was applied to some chelate metal complexes, and, as a result, various complex materials could be obtained. RGB (red, green, and blue) emission was achieved using only chelate metal complexes, after successfully obtaining high-luminance blue-emitting materials, such as azomethine-zinc complex. This shows that the chelate metal complexes can be applied to full-color flat displays as an emitting material. As for durability, when Bis(10-hydroxybenzo[h]quinolinato)beryllium (BeBq₂) was used as an electron transport layer, a lifetime (initial luminance: 500 cd/m ²) of more than 3500 h, which is a practical level, was achieved in running tests. Thus, it seems that chelate metal complexes are a strong candidate as an organic EL material in practical use     

基于混合配体Znq(DBM)的单色和白色OLED

以8-羟基喹啉(q)和1,3-二苯基-1,3-丙二酮定向合成了有机小分子配合物Znq(DBM),将其作为发光层制备了单色有机电致发光器件(OLED)。在结构为ITO/m-MTDATA(5nm)/NPB(40nm)/Znq(DBM)(60nm)/LiF(0.5nm)/Al(100nm)的器件中,启亮电压为5V,最大亮度达到4 575cd/m2。同时又在器件中引入间隔层BCP,研究其不同厚度对OLED性能的影响。在结构为ITO/m-MTDATA(5nm)/NPB(40nm)/BCP(x nm)/Znq(DBM)(60nm)/LiF(0.5nm)/Al(100nm)的器件中,当BCP层厚为0nm时,发光颜色为黄绿色;当BCP层厚为1nm时,发光颜色为白色,色坐标为(0.29,0.33),最大亮度为2 231cd/m2;当BCP层厚为5nm时,发光颜色为蓝色。根据器件结构和性能,讨论了其内部机理。     

DC EL materials and techniques for flat-panel TV display

The preparation and properties of direct current electroluminescent (dc EL) materials using manganese-activated ZnS powders for a flat-panel TV display are described. The firing process, the copper coating process, and the ferming process have been investigated. Suitable powder phosphors for the display panel contain 0.1-0.5 wt % manganese and 0.25-0.35 wt % copper coated on the ZnS powder surface. Although the powder-type dc EL still has low luminous efficiency, the light output can be increased to a useful level by exciting the panel with voltage pulses of high peak power. The crosstalk effect in the display panel can also be suppressed, since the brightness is very nonlinear with respect to the applied voltage. The sealing of the panel with silicone oil is effective in lengthening the life of the panel. An experimental dc EL panel with a 13-in diagonal and 50 176 picture elements has been fabricated, capable of reproducing broadcast TV images. These images have a highlight brightness of 10 fL, a contrast ratio of 20:1, a limiting resolution of about 150 TV lines in both horizontal and vertical directions, and a gray-scale capability of 16 steps.     

新型光电阴极显示器的开发应用

详述了近贴聚集二极管像增强器与低亮度矩阵ＥＬ显示屏耦合,用光电阴极低替场发射电子,开发出一种新型显示器,该显示器可用于可视电话、自动控制、玩具、头盔和军事装备仪表以及计算机的终端显示。