共查询到19条相似文献,搜索用时 93 毫秒
1.
通过在Ag层中引入一层Ge薄膜, 获得了具有低反射率和高反射相移的Ag/Ge/Ag复合阳极, 并制备了基于该阳极的蓝光顶发射有机电致发光器件.阳极高的反射相移使得器件在有机层厚度为100 nm时获得了顶发射蓝光发射, 且阳极较低的反射率减弱了器件内的微腔效应, 使得其电致发光光谱在不同视角下具有良好的稳定性.当Ge的厚度为20 nm时, 器件性能表现最为优良, 最高亮度和最大电流效率分别可达3 612 cd/m2和5.4 cd/A, 且色坐标在视角从0°变化到60°时仅移动了(0.007, 0.006). 相似文献
2.
利用一种来源于PPV的发蓝光的齐聚物材料2,5,2',5'-tetra(4'-biphenylenevinyl)-biphenyl(TBVB)制作非掺杂的有机电致蓝光和白光器件。蓝光器件的结构为ITO/NPB/TBVB/Alq3/LiF/Al,其中TBVB用作发光层;白光器件的结构为ITO/NPB/TBVB/rubrene/Alq3/LiF/Al,其中TBVB与超薄层(平均“厚度”0.05~0.20nm)的Rubrene相结合用作发光层,二者分别发蓝光和黄光。在蓝光器件中,当TBVB的厚度为30nm时,器件发出色坐标为(0.20,0.26)的蓝光,其最大亮度和效率分别达到2154cd/m2和1.62cd/A。在白光器件中,可通过调节TBVB和Rubrene的厚度实现对器件发光色度的调节。当TBVB和Rubrene的厚度分别为10,0.15nm时,器件在亮度为4000cd/m2时发光色坐标为(0.33,0.34),非常接近白光等能点,且随着电压的变化始终处于白光区。当电压为16V时该器件达到最高亮度4025cd/m2;当电压为6V时器件有最高的效率3.2cd/A。 相似文献
3.
顶发射白光有机发光二极管(white organic light-emitting diodes,WOLEDs)因可与有源驱动电路结合实现大开口率和高分辨率,因而在白光照明和全彩显示中有着良好的应用前景.本文制备了红/蓝双磷光发光层的顶发射WOLEDs,通过在红光层与蓝光层间插入电子阻挡层tris(phenypyrazole)iridium(Ir(ppz)3),降低了对红光掺杂浓度的要求,红光掺杂浓度的提高不仅降低了对制备工艺的要求,提高了工艺可重复性,而且改善了WOLEDs的效率与色度稳定性。分析了色度稳定的原因,优化了红光和蓝光磷光客体的掺杂浓度,制备出发光效率达到7.9cd·A-1的顶发射WOLED,其色坐标位于暖白光区,在87~2 402cd·m-2亮度范围内色度很稳定,仅变化(0.006,0.01)。 相似文献
4.
采用CsN_3:Bphen/Al/HAT-CN为电荷生成单元,制备了光谱高度稳定的高效暖白光有机电致发光器件.正面出射时,暖白光器件的最大电流效率和功率效率分别为45.4cd/A、28.5lm/W;当工作电流密度从10mA/cm~2增加到30mA/cm~2时,器件色坐标几乎不变;相对色温由3 135K变至3 147K,均在暖白光范围内,这可有效避免照明器件的蓝光伤害.当观察角度由0增加到60°时,器件光谱峰值波长没有明显移动,色坐标变化为(0.02,0.03),且光强分布接近理想的朗伯特体,呈现出良好的角度特性. 相似文献
5.
用微腔调色法来实现有机发光器件的三基色,有利于减少光损失,并提高器件的色饱和度和效率.以多波长的白光器件为基构成了微腔顶发射器件.顶发射器件以Ag作为全反射阳极,ITO为光程调节层,Al/Ag为半透明复合阴极,Alq:DCJTB/TBADN:TBPe/Alq:C545为白光发光层.通过调节ITO厚度,改变微腔光程以及器件的颜色,分别得到红、蓝、绿三基色的器件,器件发光峰值分别为475,538和603nm,色坐标分别为(0.133,0.201),(0.335,0.567)和(0.513,0.360).半高宽分别为30,48,70nm.
关键词:
有机发光
顶发射
微腔效应
三基色 相似文献
6.
蓝色微腔有机发光器件 总被引:4,自引:0,他引:4
实现彩色显示需要高效率和高色纯度的红、绿、蓝三种颜色发光.与红、绿色器件相比,蓝光有机电致发光器件(OLED)有较低效率和较差的色纯度.为了改善器件性能,将微腔引入到OLED中,优化设计并制作出蓝色微腔有机电致发光器件(MOLED):Glass/DBR/ITO/NPB/DPVBi/Alq3/LiF/Al.得到蓝光微腔器件电致发光谱(EL)峰值位于472 nm,与无腔器件相比,峰值强度增强5.4倍,半峰全宽(FWHM)减小77.1%(仅为16 nm),光谱积分强度增加33%.微腔器件最大亮度8439 cd/m2,最大发光效率2.4 cd/A,CIE色坐标为(X=0.14,Y=0.10).结果表明,由于微腔效应的存在,导致微腔器件的EL谱线窄化和峰值强度增强,可提高器件的色纯度,改善器件发光性能. 相似文献
7.
新一代白光LED照明用一种适于近紫外光激发的单一白光荧光粉 总被引:42,自引:8,他引:34
首次报道单一Sr2MgSiO5:Eu^2 材料的白光发射性质。发射光谱由两个谱带组成,分别位于470,570nm处,并具有不同的荧光寿命,归结为处于不同格位上的二价铕离子的发射,它们混合成白光。这两个发射带所对应的激发光谱均分布在250~450nm的紫外区,利用该荧光粉和具有400nm近紫外光发射的InGaN管芯制成了白光LED。正向驱动电流为20mA时,色温为5664K;发光色坐标为x=0.33,y=0.34;显色指数为85%;光强达8100cd/m^2。实验表明,器件的色坐标和显色指数等参数随正向驱动电流的变化起伏量小于5%,优于目前商用的蓝光管芯泵浦白光LED,报道的单一白光荧光粉在新一代白光LED照明领域具有广阔的应用前景。 相似文献
8.
用一种宽谱带材料Alq3作为发光层,设计并制作白色有机微腔电致发光器件。器件结构:Glass/DBR/ITO(194 nm)/NPB(93 nm) /Alq3(49 nm)/MgAg(150 nm),得到了位于蓝(488 nm)和红(612 nm)光区域的两个腔发射模式,并通过颜色匹配获得了白光。器件的最大电致发光亮度16 435 cd/m2,最大效率11.1 cd/A,典型亮度值100 cd/m2时的发光效率、电压、电流密度分别是9 cd/A,6 V和1.2 mA/cm2,CIE 色坐标为(0.32, 0.34)。在不同的驱动电压下,器件的发光颜色稳定,说明了微腔是一种制作白光OLED的有效结构。 相似文献
9.
利用Ag/tris-(8-hydroxyquinoline) aluminum(Alq3)/Ag/Alq3/Ag这一金属/有机半导体多层结构作为阳极,实现了超低效率滚降的顶发射白光器件。在该器件中,我们在蓝光和橙光发光单元之间引入一个薄的4,4′-bis(9-carbazolyl)-2,2′-biphenyl(CBP)层,从而减少橙光发光层与蓝光发光层的Dexter能量传递,用以改善白光器件发光光谱及效率。通过优化微腔设计,实现了对橙光磷光材料发射的调控。最终,我们获得了在60 000 cd/m2亮度下效率滚降仅为17%的顶发射白光器件。在效率方面,虽然顶发射白光器件与底发射白光器件不相上下,但由于微腔效应的存在,顶发射白光器件的效率滚降却远低于底发射白光器件的效率滚降。 相似文献
10.
以Ag/ITO为全反射阳极,以Al/Ag为半透明复合阴极,制备了绿色、蓝色两种微腔结构顶发射有机发光器件,研究了微腔效应对顶发射器件颜色的影响,通过调节光程,实现了用同一种有机发光层制备出不同波长的发射.Alq基顶发射器件得到波长峰值从500 nm到584 nm的不同颜色的器件,发光光谱半高宽由传统器件的100 nm窄化到20—40 nm,最高电流效率1.77 cd/A.蓝光顶发射器件发光峰值从464 nm变化到532 nm,半高宽由传统器件的65 nm窄化到17—21 nm,并得到色坐标为(0.141,0.049)的深蓝色顶发射有机发光器件.
关键词:
有机发光
顶发射
微腔效应 相似文献
11.
Shihao Liu Xuemei WenWenbo Liu Wei ZhangJing Yu Wenfa XieLetian Zhang 《Current Applied Physics》2014,14(11):1451-1454
Angle-stable white top-emitting organic light-emitting devices (WTEOLEDs) by the combination of a blue TEOLED with a down-conversion (DC) layer are demonstrated. The DC layer is composed of red fluorescent dye doped in a host of tris (8-hydroxy-quinolinato) aluminum. The TEWOLED shows a CIE coordinates of (0.240, 0.332) and a maximum current efficiency of 3.95 cd/A. Furthermore, the WTEOLED shows excellently angle-stable characteristic, the CIE coordinates at 20 mA/cm2 only shift by (0.023, −0.007) from 0° to 60°. It can be attributed to the angle-stable blue TEOLED based on the Ag/Ge/Ag transparent cathode. 相似文献
12.
Efficient top-emitting white organic light emitting device with an extremely stable chromaticity and viewing-angle 下载免费PDF全文
In this paper,we report on the fabrication of a top-emitting electrophosphorescent p-i-n white organic lightemitting diode on the basis of a low-reflectivity Sm/Ag semi-transparent cathode together with a thickness-optimized ZnS out-coupling layer.With a 24-nm out-coupling layer,the reflectivity of the cathode is reduced to 8% at 492 nm and the mean reflectivity is 24% in the visible area.By introducing an efficient electron blocking layer tris(1phenylpyrazolato,N,C2 ’)iridium(III)(Ir(ppz) 3) to confine the exciton recombination area,the current efficiency and the colour stability of the device are effectively improved.A white emission with the Ir(ppz) 3 layer exhibits a maximum current efficiency of 9.8 cd/A at 8 V,and the Commission Internationale de L’Eclairage(CIE) chromaticity coordinates are almost constant during a large voltage change of 6 V-11 V.There is almost no viewing angular dependence in the spectrum when the viewing angle is no more than 45,with a CIE x,y coordinate variation of only(±0.0025,±0.0008).Even at a large viewing angle(75),the CIE x,y coordinate change is as small as(±0.0087,±0.0013). 相似文献
13.
利用两种颜色的发光层制备了光谱稳定的高效混合WOLED。其中蓝光发光层用14%质量分数的BNE掺杂在BePP2中,橙光发光层用1%质量分数的Ir(bt)2(acac)掺杂在49.5%质量分数的NPB和49.5%质量分数的BePP2组成的混合主体中。在不利用任何光耦合技术的条件下,器件在亮度为100 cd/m2时,功率效率可以达到39 lm/W;当亮度提高到1 000 cd/m2时,效率仅发生轻微滚降至27.5 lm/W。器件的光谱稳定,亮度在1 000 cd/m2和10 000 cd/m2时,CIE坐标分别为(0.37,0.48)和(0.37,0.47)。良好的光谱稳定性归结于设计的双极性中间层平衡了其两侧激子的产生。 相似文献
14.
This work demonstrates the fabrication of a bright blue organic light-emitting diode (BOLED) with good color purity using 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi) and bathocuproine (BCP) as the emitting layer (EML) and the hole-blocking layer (HBL), respectively. Devices were prepared by vacuum deposition on indium tin oxide (ITO)-glass substrates. The thickness of DPVBi used in the OLED has an important effect on color and efficiency. The blue luminescence is maximal at 7670 cd/m2 when 13 V is applied and the BCP thickness is 2 nm. The CIE coordinate at a luminance of 7670 cd/m2 is (0.165, 0.173). Furthermore, the current efficiency is maximum at 4.25 cd/A when 9 V is applied. 相似文献
15.
Bozhi Liu Ruifeng Li Lian Hu Huizhen Wu 《Applied Physics A: Materials Science & Processing》2014,116(3):941-945
A novel white light-emitting diode based on a large Stokes shift (~200 nm) and using pure green light-emitting CdSeS quantum dots (QDs) with an Ag/ZnSnO/QDs/spiro-TPD/ITO structure has been fabricated in which ZnSnO and spiro-TPD are served as the electron and hole transport layer, respectively. The large Stokes shift of the CdSeS QDs excludes potentially Förster resonance energy transfer process, which allows spiro-TPD to act as both an emitter and hole transport layer. The devices exhibit a wide EL spectrum consisting of three components: blue emission from spiro-TPD, green emission from QD band–band recombination, and red emission from QD surface-state recombination. We further found that as the intensity ratios among these three components vary with bias the color of the QD light-emitting diodes is tunable. The device displays a good white light-emitting characteristic with CIE coordinates of (0.281, 0.384) at an appropriate bias. 相似文献
16.
选用一种新型高效的蓝光有机小分子荧光染料TBPe,首次制备了以PVK:TBPe为蓝光发光层和Alq3:rubrene为橙红光发光层的双层白光有机电致发光器件,器件结构为ITO/PVK:TBPe/Alq3:rubrene/Mg:Ag。通过适当调节各有机层的掺杂比例和厚度,得到了发光性能比较理想的白光器件。器件在7V左右启亮,而且随着外加电压的变化,色坐标基本保持不变,在外加驱动电压为16V时,器件的亮度为738cd/m2,外量子效率为0.2%。我们还尝试选用本身可以发绿白光,而且兼具电子传输特性的母体材料Zn(BTZ)2替代Alq3,器件的最大亮度提高到1300cd/m2,色坐标为(0.32,0.36),更加接近白色等能点,器件其他光电性能也得到了显著地提高。 相似文献
17.
We fabricated simple and color-stable phosphorescent white organic light-emitting diodes (OLEDs) without an interlayer using a single host of 1,3-bis(9-carbazolyl)benzene with iridium(III) bis[(4,6-difluorophenyl) pyridinato-N,C2’]picolinate and bis(1-phenylisoquinoline)(acetylacetonate) iridium(III) as blue and red phosphorescent emitters, respectively. The CIE 1931 color coordinate difference of the white OLEDs is (0.008, 0.007) when the luminance of the device is increased from approximately 265 cd/m2 to 9156 cd/m2, which is regarded as visually indistinguishable in practice. In addition, we also measured the decay time of excitons to investigate the emission mechanism in this device using transient photoluminescence and electroluminescence techniques. 相似文献
18.
制备了多层结构合成的白光有机电致发光器件(WOLEDs),通过在发光层中加入一层空穴阻挡层TPBi来提高器件的光谱稳定性。当TPBi厚度为2.5 nm时,在电压由8 V升高到12 V的过程中,CIE色坐标的变化量为(0.031,0.006)。器件的电流效率为24.7 cd/A,外部量子效率最大为8.2%。相对于没有加入中间层的器件,8 V电压下的色坐标由(0.435,0.472)变为(0.333,0.439)。实验结果表明,在发光层中添加中间层可以改变器件发光的色坐标并提升光谱的稳定性。 相似文献