双层有机电致发光器件中多成分激发态发射

在结构为ITO/TPD(60nm)/PBD(60nm)/Al的双层器件观察到了单体发射、激基复合物发射和电荷对复合物发射.该器件和TPD∶PBD(等摩尔)混合蒸发薄膜的光致发光光谱研究表明激基复合物仅在TPD/PBD界面形成.电致发光光谱随偏置变化，反映出各激发态的不同形成机理和不同的占有比例及载流子在器件中动态复合的过程. 关键词： 电致发光 激发态发射 激基复合物 电荷对复合物     

A terbium (III) complex with triphenylamine-functionalized ligand for organic electroluminescent device

A novel ligand, 4-diphenylamino-benzoic acid (HDPAB), and the corresponding Tb (III) complex, Tb (DPAB)₃ which can be dissolved easily in organic solvents were synthesized and characterized. Organic electroluminescent (EL) device with a structure of indium tin oxide (ITO)/poly(N-vinylcarbazole) (PVK): Tb (DPAB)₃ (50 wt%, 80 nm)/1,3,5-tris-(N-phenylbenzimidazol-2-yl)benzene (TPBI) (30 nm)/tri(8-hydroxyquinoline)aluminum (AlQ) (20 nm)/LiF (1 nm)/Al (150 nm) in which Tb (DPAB)₃ acted as an emitter were fabricated. The maximum luminance of 230 cd m⁻² at 20 V and the maximum efficiency of 0.62 cd A⁻¹ were obtained due to the introduction of hole-transporting group, representing the best result to date among Tb (III) carboxylate complexes based EL devices. These results indicate that modifications of rare earth complexes are a promising way to improve the properties of EL devices.     

White organic electroluminescent device with photovoltaic performances

Organic device with structure of indium tin oxide (ITO)/1,3,5-tris-(3-methylphenylphenylamino)triphenylamine (m-MTDATA)/2-tert-butyl-9,10-di-beta-naphthylanthracene (TBADN)/2,9-dimethyl-4,7-diphenyl-1,10-phenan-throline (BCP)/LiF/Al, was fabricated, which show high efficient white electroluminescence (EL) or photovoltaic (PV) properties when it was driven by direct current (DC) bias or illuminated by ultraviolet (UV) light. Under a DC bias, the device shows efficient white EL emission. A maximum luminous efficiency of 1.1 lm/W was obtained at 8 V, which corresponds the Commission International de L’Eclairage coordinates (CIE) of (x = 0.298, y = 0.365). When the bias was increased to 12 V, the device shows bright white emission with the maximum brightness of 4300 cd/m², corresponding CIE coordinates of (x = 0.262, y = 0.280). When the diode was irradiated by a 365 nm UV-light (4 mW/cm²), the open-circuit voltage (V_oc) of 1.2 V, short-circuit (I_sc) of 0.065 mA/cm², fill factor (FF) of 0.24 and power conversion efficiency of 0.47% have been determined, respectively. The generation mechanisms of white light and PV of the bi-functional diode were discussed as well.     

同时掺杂磷光和荧光染料的白色有机电致发光器件性能研究

以磷光染料Ir(piq)₂(acac)作为发光掺杂剂,掺入空穴传输性主体材料NPB中得到红色发光层,荧光材料TBP掺入到主体CBP中作为蓝色发光层,制备了结构为ITO/NPB/NPB：Ir(piq)₂(acac)/CBP/CBP：TBPe/BCP/ALq/Mg：Ag的双发光层白色有机电致发光器件.其中ALq₃、未掺杂的NPB和CBP及BCP层分别作为电子传输层、空穴传输层和激子阻挡层.实验中通过调节发光层厚度及Ir(piq)_{2关键词： 磷光 激子阻挡层 有机电致发光}     

Organic single-quantum-well electroluminescent device

A new kind of single-quantum-well electroluminescent (EL) device consists of a hole transport N,N-Bis(3-methyphenyl)-N,N-diphenylbenzidine(TPD) layer, and electron transport 8-(quinolinolate)-aluminum(Alq) layer and a light emitting layer of Alq doped with 5,6,11,12-tetraphenylnaphthacene (rubrene) has been fabricated by the multisource-type high-vaccum organic molecular deposition. The dopant rubrene is as a potential well, and the undoped Alq layer is as a barrier layer. The EL spectra shows the spectral narrowing and the emission peak energy blue-shift, and the efficiency and luminance of the device have been significantly improved. The experimental phenomena is explained as the result of recombination of carriers from the quantized energy state.     

基于一种新型有机金属配合物的量子阱结构有机电致白光器件的性能研究

利用一种新型有机金属配合物二(2-(4-三氟甲基-2-羟基苯基)苯并噻唑锌(Zn(4-TfmBTZ)₂),基于NPB/Zn(4-TfmBTZ)₂界面电致激基复合物,制备了一系列异质结量子阱结构有机电致白光器件.结果表明,量子阱结构可以有效提高界面电致激基复合物的发光效率以及器件的显色指数和色度稳定性.得出器件ITO/NPB (60 nm)/Zn(4-TfmBTZ)₂(3.0 nm)/NPB (4.0 nm)/Zn(4-TfmBTZ)_{关键词： 二(2-(4-三氟甲基-2-羟基苯基)苯并噻唑锌 电致激基复合物 量子阱 白光}     

Enhancement of electroluminescent properties of organic optoelectronic integrated device by doping phosphorescent dye

Organic optoelectronic integrated devices(OIDs) with ultraviolet(UV) photodetectivity and different color emitting were constructed by using a thermally activated delayed fluorescence(TADF) material 4, 5-bis(carbazol-9-yl)-1, 2-dicyanobenzene(2 CzPN) as host. The OIDs doping with typical red phosphorescent dye [tris(1-phenylisoquinoline)iridium(Ⅲ), Ir(piq)_3], orange phosphorescent dye {bis[2-(4-tertbutylphenyl)benzothiazolato-N,C~(2')]iridium(acetylacetonate),(tbt)_2 Ir(acac)}, and blue phosphorescent dye [bis(2, 4-di-fluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(Ⅲ), FIr6] were investigated and compared. The(tbt)_2 Ir(acac)-doped orange device showed better performance than those of red and blue devices, which was ascribed to more effective energy transfer. Meanwhile, at a low dopant concentration of 3 wt.%, the(tbt)_2 Ir(acac)-doped OIDs showed the maximum luminance, current efficiency, power efficiency of 70786 cd/m~2, 39.55 cd/A, and 23.92 lm/W, respectively, and a decent detectivity of 1.07 × 10~(11) Jones at a bias of -2 V under the UV-350 nm illumination. This work may arouse widespread interest in constructing high efficiency and luminance OIDs based on doping phosphorescent dye.     

不同主体双发光层白色有机电致发光器件的性能研究

制备了结构为ITO/NPB/CBP:TBPe:rubrene/BAlq:Ir(piq)₂(acac)/BAlq/Alq₃/Mg:Ag的白色磷光有机电致发光器件.利用两种不同的主体材料,即用双载流子传输型主体材料CBP掺杂荧光染料TBPe及rubrene作为蓝光和橙黄光发光层;用电子传输型主体材料BAlq掺杂磷光染料Ir(piq)₂(acac)作为红色发光层.以上双发光层夹于空穴传输层NPB与具有电子传输性的阻挡层BALq之间.讨论了如何控制 关键词： 有机电致发光 磷光染料 掺杂 白光     

不同主体双发光层白色有机电致发光器件的性能研究

制备了结构为ITO/NPB/CBP:TBPe:rubrene/BAlq:Ir(piq)₂(acac)/BAlq/Alq₃/Mg:Ag的白色磷光有机电致发光器件.利用两种不同的主体材料,即用双载流子传输型主体材料CBP掺杂荧光染料TBPe及rubrene作为蓝光和橙黄光发光层;用电子传输型主体材料BAlq掺杂磷光染料Ir(piq)₂(acac)作为红色发光层.以上双发光层夹于空穴传输层NPB与具有电子传输性的阻挡层BALq之间.讨论了如何控制     

Progress in molecular organic electroluminescent materials

Efficient electroluminescence from sublimated organic films at low voltage was first reported in 1987. Since then, an important volume of academic and industrial research has been realized in order to develop new efficient materials with high life time but also to optimize the technological steps of the devices fabrication. So, in this paper, the best known materials to date are described.     

Blue organic electroluminescent devices based on a distyrylarylene derivative as emitting layer and a terbium complex as electron-transporting layer

With a blue distyrylarylene derivative, 4,4′-bis(2,2-di(2-methoxyphenyl)ethenyl)-1,1′-biphenyl (CBS) as emitting material, double-layer and triple-layer electroluminescent (EL) devices were fabricated. For the device using tris-(1-phenyl-3-methyl-4-isobutyryl-5-pyrozolone)-bis(triphenyl phosphine oxide) terbium (Tb(PMIP)₃(TPPO)₂) as the electron-transporting layer, blue EL emission with a maximum luminance of 253 cd/m² was achieved at 19 V. The difference of Tb(PMIP)₃(TPPO)₂ and tris(8-hydroxyquinolinate)aluminum (AlQ) as the electron-transporting materials in these devices were compared and discussed.     

Application of organic electroluminescent materials in visualisation

Organic semiconductors have now proven their ability to be incorporated as the active layer in a light emitting diode. We report here on the status of emerging materials (both evaporated molecules and polymers), then we consider colour patterning and addressing issues. Finally, we describe the first commercial OLED displays and we review the different demonstrators which have been disclosed so far.     

Isophorone derivative as red dopant for organic electroluminescent devices

The donor–acceptor functionalized molecule, bis(4-(2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl)phenyl)(1-naphthyl)amine (DPN-4CN), with symmetrical structure, was investigated for its application in optoelectronic devices. Red organic light-emitting diodes (OLEDs) were fabricated by doping DPN-4CN in tris(8-hydroxyquinolino) aluminum (Alq₃) as red emitters, with a structure of ITO/NPB/Alq₃:DPN-4CN/BCP/Alq₃/LiF/Al. The device with a doping concentration of 2.5 wt% showed pure red emission with λ_max at 654 nm and CIE coordinates of (0.62, 0.36), a high brightness of 5080 cd m⁻² at a driving voltage of 12 V, a current efficiency of 2.14 cd A⁻¹ and an external quantum efficiency of 1.07% at a current density of 20 mA cm⁻². The current efficiencies and CIE coordinates of the device were almost constant over a current density from 1 to 200 mA cm⁻².     

Synthesis and electroluminescent properties of a carbozole-functionalized europium(III) complex

A novel europium(III) complex, tris(dibenzoylmethanate){1-[9-hexyl-9H-carbazole]-2-(2-pyridyl)-benzimidazole}europium(III) [Eu(DBM)₃(CAR-PyBM)] functionalized by a carbozole fragment, was synthesized and used as emitting material in organic electroluminescent (EL) devices. Compared with the device based on an unfunctional Eu(III) complex, [Eu(DBM)₃HPyBM] (HPyBM=2-(2-pyridyl)benzimidazole), the EL performances of the device using [Eu(DBM)₃(CAR-PyBM)] as an emitter was significantly enhanced due to the improvement of hole-transporting ability. The maximum efficiency and luminance of red emission achieved from the device with the configuration of ITO/N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′diamine (TPD, 50 nm)/ [Eu(DBM)₃(CAR-PyBM)] (30 nm)/1,3,5-tirs-(N-phenylbenzimidazol-2-yl)benzene (TPBI, 20 nm)/LiF (1.5 nm)/Al were 4.2 cd/A and 200 cd/m², respectively.     

Exciplex formation and electroluminescent absorption in ultraviolet organic light-emitting diodes

We investigated the formation of exciplex and electroluminescent absorption in ultraviolet organic light-emitting diodes(UV OLEDs) using different heterojunction structures.It is found that an energy barrier of over 0.3 eV between the emissive layer(EML) and adjacent transport layer facilitates exciplex formation.The electron blocking layer effectively confines electrons in the EML,which contributes to pure UV emission and enhances efficiency.The change in EML thickness generates tunable UV emission from 376 nm to 406 nm.In addition,the UV emission excites low-energy organic function layers and produces photoluminescent emission.In UV OLED,avoiding the exciplex formation and averting light absorption can effectively improve the purity and efficiency.A maximum external quantum efficiency of 1.2%with a UV emission peak of 376 nm is realized.     

Colours from electroactive polymers: Electrochromic, electroluminescent and laser devices based on organic materials

This paper focuses on the most relevant devices currently used in order to achieve electrically stimulated generations of colours from electroactive polymers, either as coloured light emissions from the material or as modifications of its intrinsic colour properties. For this purpose, most relevant materials, fundamental principles of operations, latest developments and current applications of organic-based electrochromic, electroluminescent and lasing devices are reviewed here. The very promising performances resulting from the analysis of state-of-the-art products, and in particular of those which are currently approaching commercial applications, suggest likely roles played by such devices for niche applications in the very near future.     

High-brightness white light-emitting organic electroluminescent devices using poly(N-vinylcarbazole) as a hole-transporter

A white light-emitting organic electroluminescent (EL) device with multilayer thin-film structure, which shows high-brightness and high-efficiency, is demonstrated. The device structure of glass substrate/indium–tin oxide/poly(N-vinylcarbazole) (PVK)/1,1,4,4-tetraphenyl-1,3-butadiene/8-(quinolinolate)-aluminum (Alq) doped with 5,6,11,12-tetraphenylnaphthacene/Alq/Mg/Al was employed. The turn-on voltage is as low as 2.5 V. The white light emission covers a wide range of the visible region, and the Commission Internationale de 1' Eclairage coordinates of the emitted light are (0.319, 0.332) at 10 V. Bright white light, over 20 000 cd/m², was successfully obtained at about 18 V, and the maximum efficiency reaches to 1.24 lm/W at 9 V. The reasons of obtaining high level EL properties of our device have been discussed.     

An organic electrophosphorescent device driven by all-organic thin-film transistor using photoacryl as a gate insulator

Organic electrophosphorescent devices have been intensively investigated for using in full-color flat-panel display. Since the quantum efficiency of electrophosphorescent device decreases rapidly as the luminance increases, it is desirable to operate the electrophosphorescent display with active matrix rather than passive matrix. Here we report the study of driving electrophosphorescent diode with all-organic TFT. We obtained the maximum power luminance that was obtained about 90 cd/m². Turn-on voltage is approximately 10 V. Field effect mobility, threshold voltage, and on–off current ratio in 0.5-μm thick gate dielectric layer were 0.13 cm²/V s, −7 V, and 10⁶ A/A. The structure of electrophosphorescent diode is ITO/TPD/BCP:Ir(ppy)₃/BCP/Alq₃/Li:Al/Al. In organic TFT, photoacryl is used as an insulator and pentacene as an active layer.     

有机电致发光器件中载流子的输运和复合发光

以高场作用下载流子对三角势垒的FowlerNordheim隧穿理论为基础,建立了单层有机电致发光器件中载流子输运和复合发光模型,给出了薄膜中电子空穴对的解离和复合概率及电子和空穴的密度分布.计算并讨论了外加电压和注入势垒对器件电流和复合效率的影响. 关键词： 电致发光器件 载流子输运 载流子复合