Numerical investigations on the current conduction in bilayer organic light—emitting devices with ohmic injection of charge carriers

A numerical model for bilayer organic light-emitting diodes (OLEDs) has been developed on the basis of trappedcharge limited conduction. The dependences of the current density on the operation voltage, the thickness andtrap properties of the hole transport layer (HTL) and emission layer (EML) in bilayer OLEDs of the structure an-ode/HTL/EML/cathode have been numerically investigated. It has been found that, for given values of reduced trapdepth, total trap density, and carrier mobility of HTL and EML, there exists an optimum thickness ratio of HTL tothe sum of HTL and EML, by which a maximal current density, and hence maximal quantum efficiency and luminance,can be achieved. The current density decreases quickly with the mean trap density, and decreases nearly exponentiallywith the mean reduced trap depth.     

HD61830A在LED显示中的应用

信息的交流是促进社会发展的必要手段.若要了解大量的信息,视觉的手段比通信的方法更为方便.由此LED显示屏备受人们的欢迎.人们可在很多地方观看到用LED显示屏显示的信息.LED显示屏作为传播信息的媒介应用在各行各业上.那么如何控制LED的显示也成为工程人员们非常关心的问题.人们希望用价格比较合理,控制手段又比较方便的芯片来制作LED显示器的控制电路.     

Near-infrared electroluminescent diodes based on copper hexadecafluorophthalocyanine CuPcF16

We demonstrate the near-infrared （NIR） organic light-emitting devices （OLEDs） based on copper hexade-cafluorophthalocyanine （CuPcF16） doped into 2,2,2”-（1,3,5-benzenetriyl）tris-[1-phenyl-1H-benzimidazole] （TPBI）. The device structure is ITO/ NPB/ TPBI：CuPcF16/BCP/Alq3/Al. Room-temperature electro- luminescence is observed at about 1106 nm due to transitions from the first excited triplet state to the ground state （T1-S0） of CuPcF16. The result indicates that FSrster and Dexter energy transfers play a minor role in these devices, while the direct charge trapping is the dominant mechanism. The absorption spectra of CuPeF16 solution in pyridine and vacuum sublimed films on quartz have also been investigated.     

Red Light—Emitting—Diode Based on an Organic Salt

A novel organic salt trans-4-[P-(N-ethyl-N-(hydroxylethyl)-amino) styryl]-N-methylpyridinium tetraphenylborate (abbreviated as ASPT) has been employed as an active layer in an organic electroluminescent device. Bright red emission with high quantum efficiency has been obtained. The brightness of the ASPT device is one order magnitude higher than that of Alq3 devices at about 12V. The device shows high thermal stability because of the ionic interaction within the organic salt molecules. It is assumed that the high performance of such a device is related to the formation of dipole moments in the ASPT layer.     

大型多色半导体发光显示屏幕

研制成总发光象素为122880个的多色半导体发光显示屏.探讨了发光象元结构对出光效率和光强角分布的影响及第三色控制问题.描述了采用三级计算机系统控制屏幕显示的硬件和软件特点.     

Realization of Red-Organic-Light Emitting Diode by Introducing the Double Emitting Zone

A saturated red-organic-light emitting diode (OLED) has been realized by doping an emitting material both in the hole-transporting layer (HTL) and the electron-transporting layer (ETL) to form double emitting zone. The red dopant, 4-(Dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), was doped into the N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) layer and the tris (8-quinolinolate) aluminium (Alq3) layer, both of which act as the emitting layers. The optimal device, with a structure of ITO/CuPc/NPB/NPB:DCJTB/Alq3:DCJTB/Alq3/LiF/Al, showed good chromaticity coordinates (x = 0.63,y = 0.36) at 8 V. Uniquely, the current efficiency of the device was relatively independent of the drive voltage in a wide range from 8 V to 20 V. That may be helpful to ameliorate the lifetime of the organic electrol,Jmlnescent devices and to adjust the grey-scale for the future full-colour display panel.     

近白色发光的有机发光二极管

制备了以８－羟基喹啉锌Ｚｎｑ２为发光层，苯乙烯胺衍生物ＳＡ为空穴传导层，恶二唑衍生物ＰＢＤ为载流子局限层的单层双层和三层结构的有机发光二极管。研究它们的电致发光性能如电致发光光谱，电流密度电压特性和电致发光亮度电压特性等。     

染料掺杂的红色有机薄膜电致发光器件

近年来 ,有机发光二极管 (OL EDs)得到了广泛深入的研究[1～ 3] 。研究工作主要集中在探索新的有机荧光材料、载流子注入和输运材料 ,以及器件的新结构 ,力求得到发光效率高和稳定性好的各种不同颜色的发光。从目前的研究来看 ,尽管蓝色和绿色发光材料的效率已经足够高到实用 ,但红色发光材料仍然存在问题 ,对红色发光进行研究是非常必要的。有两条实现红色发光的途径 :掺杂能发红光的染料和用稀土离子配合物作基质或激活剂。利用能量传递的原理 ,在有机基质材料中掺杂荧光染料是获得高效、长寿命和所希望发光颜色的一种有效而简单的方法…     

平板显示技术比较及研究进展

平板显示因具有体积小、重量轻、功耗低、画质好等优点,已被广泛应用于电子仪表显示、车载显示、数码相机、智能手机、个人电脑、电视产品等领域之中。本文介绍了薄膜晶体管液晶显示(Thin Film Transistor-Liquid Crystal Display,TFTLCD)、有机发光二极管Organic Light Emitting Diode(OLED)显示、量子点发光二极管Quantum Dot Light Emitting Diode(QLED)显示及微发光二极管(Micro-LED)显示这几种平板显示技术的结构及原理。从结构、材料、性能、应用几方面对这几种平板显示技术进行了比较。最后给出了这几种平板显示技术的最新研究进展。LCD显示经过多年发展,技术成熟,成本低廉,仍然在显示市场占据主流地位。OLED显示技术摆脱了传统LCD的背光源,开创了自发光显示的未来发展方向。在相当一段时期内,LCD和OLED仍将会共存于市场中,相互竞争和补充。QLED显示和Micro-LED显示这两种显示技术,在理论上较OLED显示具有更好的颜色表现、更长的工作寿命等优势,具有非常广阔的发展前景,将为未来显示行业提供更多更好的选择。     

有机电致发光材料分子与器件结构设计

有机电致发光器件是当今显示器件的研究热点，越来越多的人们致力于开发高性能的发光材料和研制高效率的器件结构。本文就有机发光材料的分子结构设计，以及提高有机发光器件性能的主要途径作一简要论述。     

High—Efficiency Organic Double—Quantum—Well Light—Emitting Devices Using 5,6,11,12—Tetraphenylnaphthacene Sub—monolayer as Potential Well

The double-quantum-well organic light-emitting devices of indium-tin-oxide (ITO)/NPB (50nm)/rubrene (0.05nm)/NPB (4nm)/rubrene (0.05nm)/Alq3 (50nm)/LiF (0.5nm)/Al were fabricated, in which N,N-bis-(1-naphthyl)-N,N‘-diphenyl-1,1‘-biphenyl-4,4‘‘‘‘‘‘‘‘-diamine (NPB) is used as a barrier potential or hole transport layer, tris (8-hydroxyquinoline) aluminium (Alq3) used as electron transport layer, and 5,6,11,12-tetraphenylnaphthacene (rubrene) as a potential well and emitter. The brightness can reach 18610cd/m^2 at 13V. The maximum electroluminescent efficiency of the device was 6.61cd/A at 7V, which was higher than that of common dope-type devices. In addition, the electroluminescence efficiency is relatively independent of the drive voltage in the range from 5 to 13V.     

未来重要光源——发光二极管

在电灯发明之后的100多年里,照明技术的不断发展使白炽灯和荧光灯面临着严重的威胁.特别是发光二极管技术的逐步成熟,引发了照明光源的一场技术革命.不仅仅是红绿灯,在大型屏幕显示、室内照明、汽车车灯、广告标志等所有需要光亮的地方,发光二极管都将取代传统的照明设备,成为未来的重要光源.     

Highly Efficient Polymer Light—Emitting Devices Using a New Phosphorescent Material

A new phosphorescent material bis(2-phenyl-benzoimiazole) acetylacetonato iridium(PBI)2 IrAcac)is designed and synthesized.The absorption,photoluminescence and electroluminescence are measured.The pllymer-based light-emitting devices which use polyvinylcarbazole(PVK) as host and (PBI)2 IrAcac as emitter were fabricated.These light-emitting devices show a bright green emission at 548nm,The device ITO/(PBI)2IrAcac:PVK/BCP/Alq3/Mg:Ag shows a very high efficiency.A Peak external quantum efficiency of 21.5cd/A(5.8%) was obtained at 0.1mA/cm^2.The maximum brightness is 3840cd/m^2.     

喷墨印刷有机电致发光显示材料与器件进展

随着有机电致发光显示（OLED）技术的不断发展,OLED在智能手机、智能手表和电视等市场应用不断扩大。尤其是在小尺寸智能手机市场,OLED已成为主流的显示技术,并有望逐步替代LCD技术。但在中大尺寸显示产品如平板电脑、笔记本、显示器、电视等应用领域,受限于目前真空蒸镀工艺的高成本及可靠性问题,发展较为缓慢,但市场对其需求依然很高。相比于真空蒸镀技术,通过喷墨印刷技术制备显示器件,可极大地提高材料利用率,降低设备成本,且由于其是一种增材制造方式,可减少资源消耗和环境污染,更有利于实现大面积、轻、薄、柔的显示屏制造。本文介绍了用于喷墨印刷OLED的各功能层材料研究进展,并对印刷OLED器件结构、制备工艺及器件性能进行了讨论,最后对印刷OLED的发展前景进行了展望。     

薄膜场致发光显示的研究进展

描述了薄膜场致发光显示的电学和光学性质,介绍了夹层结构,它等效齐纳二极管组成的线路。分析了影响亮度和效率的因素,主要是发光中心浓度,电子的能量和发光体的结晶状态,为了提高电子能量,提出了分层优化方案,它具有明显的优越性;为改善发光层的结晶状态,提出了厚膜扬致发光。对场致发光的机理进行了讨论,描述了多色和全色ＴＦＥＬ器件的材料和结构的研究进展。     

Numerical investigations on the current conduction in bilayer organic light-emitting devices with ohmic injection of charge carriers

A numerical model for bilayer organic light-emitting diodes (OLEDs) has been developed on the basis of trapped charge limited conduction. The dependences of the current density on the operation voltage, the thickness and trap properties of the hole transport layer (HTL) and emission layer (EML) in bilayer OLEDs of the structure anode/HTL/EML/cathode have been numerically investigated. It has been found that, for given values of reduced trap depth, total trap density, and cv~rrier mobility of HTL and EML, there exists an optimum thickness ratio of HTL to the sum of HTL and EML, by which a maximal current density, and hence maximal quantum efficiency and luminance,can be achieved. The current density decreases quickly with the mean trap density, and decreases nearly exponentially with the mean reduced trap depth.     

可调色红光有机电致发光器件

介绍了具有可调节发光光谱的高效红光有机发光二极管(OLED)器件,利用具有高三重态能量的9.9-螺二芴二苯基氧化磷(SPPO1)作为发光层的主体材料及空穴阻挡层,二(1-苯基异喹啉)(乙酰丙酮)合铱(III) (Ir(piq)2(acac))作为客体发光材料,在发光层内SPPO1的能量分别由福斯特和迪克斯特传递到Ir(piq)2(acac)的单重态和三重态从而发出红色磷光,通过调节磷光客体材料的比例得到最优器件结构,从而得到具有较好发光效率和发光亮度并可调节色纯的有机发光二极管器件。     

蓝色显示材料及器件的研究

用Ｈ２和ＣＳ２还原法制备Ｃｅ：ＳｒＳ发光材料，分析了两种方法对材料的结构及发光特性的影响，得到了最高亮度为９５０ｃｄ／ｍ＾２（１０００Ｈｚ）的Ｃｅ：ＳｒＳ薄膜电致发光（ＴＦＥＬ）器件；用高温固相法得到Ｃｅ：ＳｒＧａ２Ｓ４荧光粉，用射频溅射沉积的Ｃｅ：ＳｒＧａ２Ｓ４薄膜在６００℃以上、Ｈ２Ｓ气氛下快速热处理可以改善薄膜结晶性能，提高杂质激发峰强度，得到好的光致发光（ＰＬ）发光性能，以陶瓷片作为基片同     

可调色红光有机电致发光器件

介绍了具有可调节发光光谱的高效红光有机发光二极管(OLED)器件,利用具有高三重态能量的9.9-螺二芴二苯基氧化磷(SPPO1)作为发光层的主体材料及空穴阻挡层,二(1-苯基异喹啉)(乙酰丙酮)合铱(III) (Ir(piq)2(acac))作为客体发光材料,在发光层内SPPO1的能量分别由福斯特和迪克斯特传递到Ir(piq)2(acac)的单重态和三重态从而发出红色磷光,通过调节磷光客体材料的比例得到最优器件结构,从而得到具有较好发光效率和发光亮度并可调节色纯的有机发光二极管器件。