ACEL 荧光粉粉末 ZnS:Cu,X 的电荷陷阱的性质与其电致发光频谱之间的联系

ZnS:Cu,X(X = Cl,Br,I) ACEL 荧光粉的性质主要决定于 Cu 发光中心的电子发光复合、ZnS 点阵中电子的注入效率、诱捕电子和逃逸电子的比率.热致发光中的电子陷阱依赖于掺杂剂以及荧光粉制备方法.文章描述了 ACEL 荧光粉的退火过程对其电致发光性质的深远影响.从热释光发光曲线上,我们可以看到烧结条件对电子陷阱特征的作用.由于荧光粉的 ACEL 性质与电子陷阱有关,为了提高荧光粉的性能,对电子陷阱的成因和所起的作用的了解就显得尤为重要.     

作为携带、沉积纳米荧光粉颗粒和纳米铁电体颗粒到FEDs 和 EL 器件上的载体的可印刷的油墨、粘结剂

文章介绍了两种移植和可控纳米沉积荧光粉颗粒和纳米铁电体颗粒的载体.第一种载体是一种可以悬浮和沉积合成的具有亚微米级尺寸大小的荧光粉颗粒的油墨.解决了该油墨的聚集和沉降问题,并发现该油墨具有良好的液流学性能,从而可用于印刷高分辨率的荧光粉.测量了相关的单个象素的阴极发光密度以评定这种丝网印刷油墨的可重复性.第二种载体是一种粘结剂,这种粘结剂不仅可以携带 30 μm 以及更大的尺寸的电致发光的荧光粉,还可以携带纳米铁电体颗粒.这种新型的粘结剂可应用于不需要额外的绝缘反射层的低造价的 EL 显示器.从衬底按要求将发射层剥下来就形成了柔性薄膜,将该薄膜置于两电极之间,仍可保持其电致发光的活性.该粘结剂薄膜可以很容易地印刷和定型制成显示屏.     

电致发光灯应用辨析

电致发光灯的原理和结构 电致发光灯(E L,Electroluminescent)的原理简单说是把电能转换成光能,即通过交变电流触发荧光层发光.电致发光灯的结构像电容器,它是在两个薄电极之间夹上一层很薄的无机ZnS化合物作为发光荧光粉.其中一个电极是不透明的,另一个是透明的,允许光输出.     

AC和DC电致发光显示器

1.EL显示器的定义和结构电致发光可定义为加电场到固体则有光直接发射而不产生热,荧光粉是定义为将一些形式的能量转化为光的材料,因此,光致发光荧光粉(经常点)将短波的光转化为长波的光,阴极射线荧光粉将电子的能量转化为光,而EL荧光粉则是将电能直接变为光,可以以下过程来相比:光致发光——没有场跨过荧光粉——无热电子。阴极射线发光——无场穿过荧光粉——热电子。电致发光——高电场穿过荧光粉——热电子。所有平板大面积EL显示的基本结构如图(略)     

用连续沉积MOCVD技术制备5英寸的ZnS:MnTFEL屏

引言由于薄膜电致发光(TFEL)显示器具有高亮度和高效率,所以它作为一种平板显示器而受到人们的关注。然而,目前巳实现商品化的仅有黄色发光ZnS:Mn器件。ZnS∶Mn荧光粉薄膜和绝缘层是用物理汽相沉积(PVD)或化学汽相沉积技术制备     

原子层外延生长的发绿光TFEL器件

引言自80年代中期,单色(黄色)薄膜电致发光(TFEL)显示屏已经在市场上出现。然而,人们对于研制多颜色TEEL显示器的要求有所增加。在过去的五年中,研制其它的TFEL彩色荧光粉比研制发黄色光的ZnS:Mn更有进展。虽然TFEL仍然需要改进,但对于生产具有极好外观,中等成本和低功耗的平板显示器来说,它仍然是一个有力的竞争者。自从首次发表TbF_3分子发射中心方面的结果以来,作为一种有用的发绿色光EL荧光粉,ZnS:Tb是最有前途的选择材料。目前,最好的绿色TFEL荧光粉已接近实际     

电致发光显示器（EL）国内外概况

电致发光显示器(EL)有使用ZnS这样荧光体发光的真性EL和象LED那样的电荷注入型发光的两种。 1.结型电致发光:在电场作用下少数载流子向p-n结的另一方注入,同多数载流子复合而产生的发光现象。这类器件称为注入式发光二极管(LED)。 2.本征式电致发光:用电场直接激励电子,使电子同空穴复合而产生的发光现象。这类发光方式通常可分成以下三种: (1)粉末电致发光:荧光粉掺在电介质中加交流电压使其发光;     

使用高介电常数多层陶瓷衬底的新型薄膜电致发光器件

已研制成功一种使用多层薄膜和陶瓷衬底的新型复合结构交流电致发光器件.发光薄膜(ZnS:Mn)和ITO电极淀积在一块由高电介质陶瓷绝缘层(e_s～10~4),内部印刷电极和陶瓷基板构成的多层陶瓷衬底上.这种器件具有工作电压低(40-80V),无击穿故障,清晰度高的特点.     

光电、光敏与发光材料

2001805共激活剂 Br~-、I~-对 ZnS:Mn,Cu·X 发光性能的影响[刊]/李志强//发光学报.—1999,20(增刊).—121～123(E)2001806橙色电致发光屏的发光特性[刊]/董国义//发光学报.—1999,20(增刊).—118～120(E)2001807退火处理对 ZnS:Cu 蓝色粉末 ACEL 的影响[刊]/韦志仁//发光学报.—1999,20(增刊).—115～117(E)2001808     

X-射线衍射与火焰原子吸收法联合测定ZnS：Mn薄膜屏中Mn含量

提出一种X-射线衍射(XRD)与火焰原子吸收法(FAAS)联合测定ZnS:Mn交流电致发光(ACEL)薄膜中Mn含量的新方法.首先用XRD测定ZnS薄膜的结构,判断薄膜是否符合它的化学式量.在符合化学式量基础上,再用FAAS分别测定Zn与Mn的质量分数,最终确定Mn在ZnS薄膜中的含量.与单独采用FAAs测定相比较,测定结果的相对误差,相对标准偏差相同.但是,该方法具有样品处理简单,分析周期短,所需样品量少等优点.不仅可以提供Mn在ZnS薄膜中的含量与构成质量,同时也可以对ZnS:Mn交流电致发光膜薄的浓度分布以及均匀度提供客观的评价指标,以利于镀膜工艺中各参数指标的改善.     

白色发光的电致发光显示器

在ZnS中加入Mn、Cu中心制备出白色发光的电致发光材料，发射光谱中可出现3个发光峰，分别是460nm、520nm和585nm。深入研究了Mn、Cu中心的分布和2个中心在不同激发条件下的相互作用，在低压区Mn中心受Cu中心的敏化，高压区Mn中心碰撞激发，利用两中心激发机理不同，适当选择合适条件，实现白光。     

Solution‐Processable,High‐Performance Flexible Electroluminescent Devices Based on High‐k Nanodielectrics

Flexible alternating‐current electroluminescent (ACEL) devices have attracted considerable attention for their ability to produce uniform light emission under bent conditions and have enormous potential for applications in back lighting panels, decorative lighting in automobiles, and panel displays. Nevertheless, flexible ACEL devices generally require a high operating bias, which precludes their implementation in low power devices. Herein, solution‐processed La‐doped barium titanate (BTO:La) nanocuboids (≈150 nm) are presented as high dielectric constant (high‐k) nanodielectrics, which can enhance the dielectric constant of an ACEL device from 2.6 to 21 (at 1 kHz), enabling the fabrication of high‐performance flexible ACEL devices with a lower operating voltage as well as higher brightness (≈57.54 cd m^?2 at 240 V, 1 kHz) than devices using undoped BTO nanodielectrics (≈14.3 cd m^?2 at 240 V, 1 kHz). Furthermore, a uniform brightness across the whole panel surface of the flexible ACEL devices and excellent device reliability are achieved via the use of uniform networks of crossaligned silver nanowires as highly conductive and flexible electrodes. The results offer experimental validation of high‐brightness flexible ACELs using solution‐processed BTO:La nanodielectrics, which constitutes an important milestone toward the implementation of high‐k nanodielectrics in flexible displays.     

ZnS∶Cu粉末交流电致发光器件特性研究

以商用ZnS∶Cu交流电致发光粉作为发光层,以ITO作为电极制作了粉末交流电致发光器件。以交流脉冲方波为驱动电压,详细研究了外加电压的幅值,频率以及脉宽对其发光频谱及亮度的影响。实验结果表明当电压小于200 V,发光亮度随着电压的升高而缓慢增强,当电压大于200 V,随着电压的升高亮度准线性增强。随着驱动频率的增大,发光光谱的中心波长发生蓝移,从100 Hz时的504 nm(绿光)到100 kHz时的450 nm(蓝光),发光亮度随频率增加先快速增强然后逐渐趋于饱和,达到一个极值后开始减小。随着脉宽的增大,发光亮度线性增强。另外文章中对驱动频率影响发光光谱的原因进行了深入分析,这对进一步研究ZnS∶Cu交流电致发光粉的发光机理有着重要的作用。     

长寿命电致发光暗室显示器的光谱研究

长寿命电致发光暗室显示器的光谱研究朱宁，孟宪棫，石磐（天津理工学院光电显示研究室，天津３００１９１）利用感光胶片对特种波长感光灵敏度低和电致发光单色性的特点，作出了系列暗室照明光源和显示器件［１．２．３．４］．根据天津感光胶片公司提出航空胶片生产车间...     

Effect of the Cu content and ZnS treatment on the characteristics of synthesized ZnS:(Cu,Cl) electroluminescent phosphors

The effect of the pretreatment of ZnS via different methods on the characteristics of synthesized ZnS:(Cu, Cl) electroluminescent phosphors with varying concentrations of the activator dopant (Cu) is studied. As a result of the pretreatment of ZnS with accelerated electrons and in nitrogen plasma, an increase in the emission brightness of the synthesized phosphor and a shift of the luminescence spectrum to longer wavelengths are observed. These effects are attributed with increase in content of the activator in the phosphor matrix because of the formation of extra defects in the ZnS structure during treatment. In the case of shockwave treatment of ZnS, the generation of defects is not compensated by heat treatment during synthesis of the phosphor, and a positive enhanced-brightness effect is not attained.

     

新型Ba_2ZnS_3∶Cu荧光粉的合成及其发光性能

采用双坩埚嵌套高温固相法在950℃下成功地合成了Ba2ZnS3∶Cu荧光粉,探讨了工艺条件和Cu掺杂量对样品发光亮度的影响,用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)和荧光分光光度计分别对其结构、形貌和发光性能进行了表征。结果表明:样品具有单一的Ba2ZnS3晶相结构;与Ba2ZnS3基质不同,该荧光粉的激发光谱在近紫外区存在一个从275～350nm的宽激发带,归因于Cu发光中心的吸收;该荧光粉在近紫外光激发下发出明亮的黄光,发射中心波长位于560nm处,是一种良好的黄光材料。     

White ACPEL Device with ZnS:Cu,Cl, Tb3Al5O12:Ce3+, and CaS:Eu2+ Phosphors Using a Layered Structure

Improvement of the color rendering index (CRI) and luminance of a white alternate current powder electroluminescent (ACPEL) device has been attempted using ZnS:Cu,Cl, Tb₃Al₅O₁₂:Ce (TAG:Ce), and CaS:Eu phosphors with a layered structure. The device with TAG:Ce and ZnS:Cu,Cl phosphors showed a CRI of 75, with a luminance increase of about 30% depending on the thickness of the TAG:Ce. Further CRI improvement was attempted using CaS:Eu. When they were separately screen‐printed, the CRI was increased up to 89 with no decrease in luminance.     

Optically Transparent and Mechanically Robust Ionic Hydrogel Electrodes for Bright Electroluminescent Devices Achieving High Stretchability Over 1400%

To realize wearable displays and interactive soft robots, significant research efforts are focused on developing highly deformable alternating-current electroluminescent (ACEL) devices. Although soft emission layers are well developed, designing stretchable, conductive, and transparent soft electrodes remains challenging. In this study, ionic hydrogels are prepared comprising a double network (DN) of poly(N-hydroxyethylacrylamide-co-acrylamide)/crosslinked chitosan swollen in aqueous lithium bis(trifluoromethanesulfonyl) imide. Owing to the finely tuned DN structure of the polymeric crosslinker and transparent electrolyte, the developed ionic hydrogels exhibit remarkable stretchability (1400%), excellent optical transmittance (>99%), and high conductivity (1.95 × 10⁻² Sm⁻¹). Based on the high performance of the ionic hydrogels, ACEL devices are fabricated with an emission layer containing phosphor microparticles and demonstrate stable, high luminance under extreme deformation, and ultra-high elongation. The excellent transparency of the ionic hydrogel further enables the fabrication of novel soft ACEL devices with tandem structures by stacking several emission and electrode layers, in which each emission layer is independently controlled with a switch circuit.     

Sputter deposition of phosphors for electroluminescent flat panel displays

Thin film electroluminescent (TFEL) phosphors for flat panel displays have been produced by several different growth methods including atomic layer epitaxy, chemical vapor deposition, and sputter deposition. There is a great deal of interest in sputter deposition due to the extensive knowledge base and equipment from other existing thin film manufacturing. However, deposition of sulfide-based TFEL phosphors by conventional radio frequency magnetron sputtering has proven to be difficult due to the formation of negative sulfur ions near the target which are accelerated to the growing film by the self-bias developed on the target. This negative-ion resputtering can result in amorphization or re-sputtering of the phosphor films. In severe cases, a net sputtering of the substrate can result. In order to remedy this negative ion resputtering problem, modifications of the magnetron geometry and ion-beam sputtering have been evaluated for production of Ca_xSr_1−xGa₂S₄:Ce and SrS:Ce TFEL phosphors. Sputter deposited TFEL films also typically require a postdeposition anneal which adds to expense and can cause other problems for the flat panel display. Ion-beam assist during deposition of undoped ZnS was studied as a method to induce surface-atom mobility and a more crystalline as-deposited film for use in monochrome TFEL displays.