用有机混合物的方法优化微腔器件性能

制作了一种新型的有机电致微腔器件,将两种有机材料混合作为发光材料,通过简单改变两种材料的重量比,实现了微调腔长的目的,认为通过合理地调节两种材料的配比,可以实现微腔发光颜色的调节。两种配比的微腔器件均发出半宽很窄的双模发射(8和12 nm),而且调节两种材料的比例后所得光谱的谐振模式和强度均得到改变,但半宽却不变。另外,对比了传统异质结结构微腔和新型微腔的电流电压特性,发现通过将空穴传输材料和发光材料混合后,器件的开启电压得到了很大程度的降低(从7V降到4V)。     

微腔结构顶发射有机白光器件

结合微腔效应,通过调节不同发光层的厚度制作了顶发射有机白光器件.器件结构为Si/Ag/Ag2O/m-MTDATA/NPB/DPVBi/DCJTB:Alq3/Alq3/LiF/Al/Ag,其中DPVBi,DCJTB与Alq3的掺杂层分别作为蓝光和红光发光层,在选定490 nm的谐振波长时,通过调节DPVBi和掺杂层的厚度来实现对器件发光色度的调节.当DPVBi厚度为1 nm,电压为9 V时,器件的色坐标为(0.33,0.34),非常接近白光等能点.此项工作为利用微腔效应制作高效率高亮度顶发射白光器件奠定了基础.     

光学微腔调节顶发射单色绿光OLED微显示器件色纯度研究

有机电致发光器件的发光颜色与色纯度在很大程度上受限于有机材料本身特性,而通过光学微腔效应可以从器件结构的改变来进行色纯度的调节。本文介绍了一种通过调节有机结构中空穴传输层和电子阻挡层厚度,从而改变器件微腔腔长,获得高纯度顶发射单色发光器件的方法。利用这种方法制作的有机顶发射绿色磷光器件结构为Si Substrate/Ag/ITO/ NPB: F16CuPc(10 nm, 3%)/NPB(x nm)/ TCTA(y nm)/ mCP: Ir(ppy)₃(40 nm, 6%)/ Bphen: Liq(30 nm, 40%)/Mg: Ag(12 nm, 10%)/Alq₃(35 nm),改变NPB和TCTA的厚度,获得了高色纯度发光器件,正向出射绿光的色坐标达到(0.2092,0.7167),接近标准绿光(0.21, 0.71)。     

具有微腔结构的有机顶发射电致发光器件的光谱分析

摘要: 制做了具有微腔结构的蓝色和白色有机顶发射电致发光器件。利用TBADN:3%DSAPh和Alq3:DCJTB/TBADN:TBPe/Alq3:C545材料为发光层,在玻璃基片上,依次制备薄膜：Ag为阳极反射层, CuPc作为空穴注入层,NPB作为空穴传输层,ITO为光程调节层; Al/Ag作为半透明阴极,电极的透射率在30%左右。通过改变ITO层的厚度,TBADN:3%DSAPh器件获得了深蓝色发光光谱,色坐标为(0.141, 0.049),半高宽为17nm发光光谱,实现了窄带发射,Alq3:DCJTB/TBADN:TBPe/Alq3:C545器件得到了不同颜色（红、蓝、绿）的发光光谱,实现了对光谱的调节作用。文章对微腔顶发射器件的发射强度和发光光谱半高宽的结果进行了分析。     

高效高亮度硅基顶发射有机电致发光器件的研制

以半透明超薄金属银作为阴极,紫外臭氧处理的厚金属银作为阳极,制备了高效率高亮度的黄光硅基顶发射有机发光器件。当电压为9V时,器件的最大电流效率为4.9cd/A,当电压为17V时,器件的亮度达到14 040cd/m2。通过增加掺杂浓度及阳极厚度对器件结构进一步优化后,器件性能显著提高,其电流效率在外加电压为10V时达到11cd/A,相应亮度为21 748cd/m2.顶发射器件中存在的微腔效应能有效提高器件的发光效率以及亮度,但是也会使器件的共振波长随着观察视角的增大而蓝移。由于采用合适的发光材料,本实验制备的器件的发光峰值在0°~75°视角范围内几乎没有变化。     

硅基法布里-珀罗微腔的室温发光

提出了一种新型基于法布里-珀罗(F-P)微腔的发光器件结构.它采用PECVD方法制备的非晶硅/二氧化硅结构作为微腔中的布拉格反射腔,非晶碳化硅薄膜作为中间光发射层,通过对一维方向光子的限制,使发光层荧光强度增强,谱线变窄.通过调节发光层和反射腔膜厚及折射率,可以精确控制发光峰位.实验结果证明该结构可望实现全硅基材料的强室温可见光发射.     

硅基法布里-珀罗微腔的室温发光

提出了一种新型基于法布里 -珀罗 (F- P)微腔的发光器件结构 .它采用 PECVD方法制备的非晶硅 /二氧化硅结构作为微腔中的布拉格反射腔 ,非晶碳化硅薄膜作为中间光发射层 ,通过对一维方向光子的限制 ,使发光层荧光强度增强 ,谱线变窄 .通过调节发光层和反射腔膜厚及折射率 ,可以精确控制发光峰位 .实验结果证明该结构可望实现全硅基材料的强室温可见光发射 .     

硅基法布里—珀罗微腔的室温发光

提出了一种新型基于法布里 -珀罗 (F- P)微腔的发光器件结构 .它采用 PECVD方法制备的非晶硅 /二氧化硅结构作为微腔中的布拉格反射腔 ,非晶碳化硅薄膜作为中间光发射层 ,通过对一维方向光子的限制 ,使发光层荧光强度增强 ,谱线变窄 .通过调节发光层和反射腔膜厚及折射率 ,可以精确控制发光峰位 .实验结果证明该结构可望实现全硅基材料的强室温可见光发射 .     

顶发光单色绿光OLED微型显示器件发光层掺杂特性研究

本文设计了一种磷光顶发射结构制备单色高亮绿光OLED微型显示器件,器件结构为:ITO/2-TNATA/NPB/MCP:Ir(ppy)_3/Bphen/LiF/Mg:Ag。为获得低功耗、高亮度的绿光OLED微型显示器件,采用开口率大、益于集成的顶发射结构器件,并对发光层掺杂机制进行实验研究,通过改变掺杂比例获得较佳的器件性能。研究表明,在掺杂比分别为1.0%、1.5%、1.8%、2.0%、2.3%、2.5%的绿光OLED器件中,2.0%的掺杂器件较其他比例的性能更优,通过进一步优化掺杂研究显示,发光层主体材料MCP与掺杂料Ir(ppy)_3的最佳掺杂比例为1:0.02,主体材料薄膜厚度为250?。在20 mA/cm~2的电流密度下,得到器件电压为3.62 V,亮度为4622 cd/cm~2,色坐标(X,Y)为(0.33,0.61)。     

基于PEN柔性衬底的顶发射微腔OLED性能研究

设计了结构为Ag/MoOx空穴注入层(HIL)/有机层/LiF/Al/Ag/Alq3的柔性有机电致发光器件(FOLED),研究通过改变HIL层的厚度改变腔长实现对微腔效应的调节,制备了性能优化的微腔FOLED。通过器件性能的对比,得到了可用Ag作为反射阳极的顶发射微腔FOLED全彩显示器件优化结构,即蓝、绿和红FOLED对应的优化HIL层厚度分别为100nm、120nm和160nm。     

微腔有机发光二极管

设计了由分布布拉格反射镜（ＤＢＲ）和金属反射镜面形成的微腔结构。利用８－羟基喹啉铝（Ａ１ｑ３）作为电子传输层兼作发光层,ＴＰＤ作为空穴传导层,了有机发光二极管（ＯＬＥＤ）和微腔有机发光二极管（ＭＯＬＥＤ）。发现ＭＯＬＥＤ的光谱工比ＯＬＥＤ的窄得多,而光密度则得到了增强,对腔长进行调节,ＭＯＬＥＤ光谱峰出现移动。实验结果与理论计算基本符合。     

Study of Configuration Differentia and Highly Efficient,Deep‐Blue,Organic Light‐Emitting Diodes Based on Novel Naphtho[1,2‐d]imidazole Derivatives

Two novel naphtho[1,2‐d]imidazole derivatives are developed as deep‐blue, light‐emitting materials for organic light‐emitting diodes (OLEDs). The 1H‐naphtho[1,2‐d]imidazole based compounds exhibit a significantly superior performance than the 3H‐naphtho[1,2‐d]imidazole analogues in the single‐layer devices. This is because they have a much higher capacity for direct electron‐injection from the cathode compared to their isomeric counterparts resulting in a ground‐breaking EQE (external quantum efficiency) of 4.37% and a low turn‐on voltage of 2.7 V, and this is hitherto the best performance for a non‐doped single‐layer fluorescent OLED. Multi‐layer devices consisting of both hole‐ and electron‐transporting layers, result in identically excellent performances with EQE values of 4.12–6.08% and deep‐blue light emission (Commission Internationale de l'Eclairage (CIE) y values of 0.077–0.115) is obtained for both isomers due to the improved carrier injection and confinement within the emissive layer. In addition, they showed a significantly better blue‐color purity than analogous molecules based on benzimidazole or phenanthro[9,10‐d]imidazole segments.     

OLED 驱动器的发展和应用

介绍了OLED/PLED的特点和目前其驱动器的发展状态。应用Solomon公司集行驱动、列驱动和控制器为一体的SSD1301芯片和低电压、低功耗的单片机W78LE58芯片,成功地驱动了96×64点阵的PLED显示屏,给出了硬件接口电路图和软件流程图。     

Merging Biology and Solid‐State Lighting: Recent Advances in Light‐Emitting Diodes Based on Biological Materials

Solid‐state lighting (SSL) is one of the biggest achievements of the 20^th century. It has completely changed our modern life with respect to general illumination (light‐emitting diodes), flat devices and displays (organic light‐emitting diodes), and small labeling systems (light‐emitting electrochemical cells). Nowadays, it is however mandatory to make a transition toward green, sustainable, and equally performing lighting systems. In this regard, several groups have realized that the actual SSL technologies can easily and efficiently be improved by getting inspiration from how natural systems that manipulate light have been optimized over millennia. In addition, various natural and biocompatible materials with suitable properties for lighting applications have been used to replace expensive and unsustainable components of current lighting devices. Finally, SSL has also started to revolutionize the biomedical field with the achievement of efficient implantable lighting systems. Herein, the‐state‐of‐art of (i) biological materials for lighting devices, (ii) bioinspired concepts for device designs, and (iii) implantable SSL technologies is summarized, highlighting the perspectives of these emerging fields.     

Light Out‐Coupling Efficiencies of Organic Light‐Emitting Diode Structures and the Effect of Photoluminescence Quantum Yield

Results obtained from modeling the light out‐coupling efficiency of an organic light‐emitting diode (OLED) structure containing the recently developed first‐generation fac‐tris(2‐phenylpyridine) iridium‐cored dendrimer (Ir‐G1) as the emissive organic layer are reported. Comparison of the results obtained for this material with those of corresponding structures based upon small‐molecule and polymer emissive materials is made. The calculations of out‐coupling efficiency performed here take account of many factors, including the photoluminescence quantum yield (PLQY) of the emissive materials. Further, how each material system might perform with regard to out‐coupling efficiency when a range of possible PLQYs are considered is shown. The calculations show that the very high efficiency of dendrimer‐based OLEDs can be attributed primarily to their high PLQY.     

Rational Design of Chelating Phosphine Functionalized Os(II) Emitters and Fabrication of Orange Polymer Light‐Emitting Diodes Using Solution Process

A new series of charge neutral Os^(II) pyridyl azolate complexes with either bis(diphenylphosphino)methane (dppm) or cis‐1,2‐bis(diphenylphosphino)ethene (dppee) chelates were synthesized, and their structural, electrochemical, photophysical properties and thermodynamic relationship were established. For the dppm derivatives 3a and 4a , the pyridyl azolate chromophores adopt an eclipse orientation with both azolate segments aligned trans to each other, and with the pyridyl groups resided the sites that are opposite to the phosphorus atoms. In sharp contrast, the reactions with dppee ligand gave rise to the formation of two structural isomers for all three kind of azole chromophores, with both azolate or neutral heterocycles (i.e., pyridyl or isoquinolinyl fragments) located at the mutual trans‐disposition around the Os metal (denoted as series of a and b complexes). These chelating phosphines Os^(II) complexes show remarkably high thermal stability, among which and several exhibit nearly unitary phosphorescence yield in deaerated solution at RT. A polymer light‐emitting device (PLED) prepared using 0.4 mol % of 5a as dopant in a blend of poly(vinylcarbazole) (PVK) and 30 wt % of 2‐tert‐butylphenyl‐5‐biphenyl‐1,3,4‐oxadiazole (PBD) exhibits yellow emission with brightness of 7208 cd m^–2, an external quantum efficiency of 10.4 % and luminous efficiency of 36.1 cd A^–1 at current density of 20 mA cm^–2. Upon changing to 1.6 mol % of 6a , the result showed even better brightness of 9212 cd m^–2, external quantum efficiency of 12.5 % and luminous efficiency of 46.1 cd A^–1 at 20 mA cm^–2, while the max. external quantum efficiency of both devices reaches as high as 11.7 % and 13.3 %, respectively. The high PL quantum efficiency, non‐ionic nature, and short radiative lifetime are believed to be the determining factors for this unprecedented achievement.     

GaN材料生长研究

用常压ＭＯＣＶＤ方法我们在蓝宝石（０００１）、Ｓｉ（１１１）衬底上，成功地制备出ＧａＮ单晶薄膜材料，取得了ＧａＮ材料的初步测试结果。纯度ＧａＮ为ｎ型，载流子浓度为１０１７～１０１８ｃｍ－３，迁移率为２００～３５０ｃｍ２／Ｖ·ｓ，双晶衍射半峰宽为７′，室温ＰＬ光谱本征发光波长为３７０ｎｍ，并首次观察到掺ＺｎＧａＮ呈ｐ型电导。     

无氧溅射方法制备OLED的ITO透明电极

采用氧化铟锡(ITO)合金材料作为靶材,通过射频磁控溅射制备ITO膜.将获得的ITO膜应用于结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/Alq3(50 nm)LiF(0.8 nm)/Al(100 nm)的有机电致发光器件(OLED),得到了最大亮度为11560 cd/m2(电压为25V)、最大效率为2.52 cd/A(电压为14 V)的结果.为了获得双面发光,制作了结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/Alq3(50 nm)LiF(0.8 nm)/Al(20 nm)/ITO(50 nm)的器件,其阳极出光的最大亮度为14460 cd/m2(电压为18V)、最大效率为2.16 cd/A(电压为12V),阴极出光的最大亮度为1 263 cd/m2(电压为19 V)、最大效率为0.26 cd/A(电压为16V).     

Influence of Bulky Organo‐Ammonium Halide Additive Choice on the Flexibility and Efficiency of Perovskite Light‐Emitting Devices

Perovskite light‐emitting diodes (LEDs) require small grain sizes to spatially confine charge carriers for efficient radiative recombination. As grain size decreases, passivation of surface defects becomes increasingly important. Additionally, polycrystalline perovskite films are highly brittle and mechanically fragile, limiting their practical applications in flexible electronics. In this work, the introduction of properly chosen bulky organo‐ammonium halide additives is shown to be able to improve both optoelectronic and mechanical properties of perovskites, yielding highly efficient, robust, and flexible perovskite LEDs with external quantum efficiency of up to 13% and no degradation after bending for 10 000 cycles at a radius of 2 mm. Furthermore, insight of the improvements regarding molecular structure, size, and polarity at the atomic level is obtained with first‐principles calculations, and design principles are provided to overcome trade‐offs between optoelectronic and mechanical properties, thus increasing the scope for future highly efficient, robust, and flexible perovskite electronic device development.     

关于提高高亮度发光二极管发光效率的探讨

使用高亮度发光二极管(HB-LED)的半导体照明技术正受到全球关注,而存在的主要问题是发光效率低。本文指出发光效率即外量子效率是内量子效率和提取效率的乘积。提高内量子效率的方法是获得高质量GaN材料的外延技术,采用四组分AlInGaN结构及在半极性面或非极性面上制作LED,提高提取效率的途径主要有倒装焊技术、表面粗化技术、芯片粘合技术、芯片成形技术以及微芯片阵列技术等。