一种有机掺杂体系的光致发光及薄膜电致发光研究

将具有薄膜电致发光（ＴＦＥＬ）性能的有机络合染料８－羟基喹啉铝（Ａｌｑ３）掺以染料罗丹明６Ｇ（Ｒ６Ｇ），用真空热蒸发的方法获得了峰值波长５７５ｎｍ的黄色直流电致发光（ＥＬ）。通过对不同掺杂浓度的粉末，溶液，薄膜样品及电致发光器件的光谱及寿命测量和对比，证实了能量传递的存在并初步探讨了可能的途径。同时发现掺杂器件ＥＬ谱的形状随驱动电压升高发生明显的改变，基质（Ａｌｑ３）的发射（相对于掺杂剂Ｒ６Ｇ的发射）明显增强，对这一现象产生的原因作了分析，并由此讨论了有机掺杂ＴＦＥＬ中复合，发射区域等问题。     

电压调节变色的有机薄膜电致发光器件

制备了结构为ＩＴＯ／ＳＡ／ＰＢＤ／Ａｌｑ３／Ａｌ的电压调制发光颜色的有机薄膜电致发光器件，研究了有机层厚度不同的器件的发光光谱随电压变化的性能，建立了器件的能级结构模型，并用这种模型解释了器件的电致发光性能。     

聚对苯乙炔的EL特性和在双层OTFEL器件中的应用

应用自制的聚对苯乙炔与Ａｌｑ３和Ｚｎｑ２做成单层、双层有机电致发光器件，研究了聚对苯乙炔的电致发光特性和在器件中的作用，发现了一些有意义的新现象，说明它是有机电致发光领域里极其重要的一种功能材料。     

聚对苯乙炔的EL特性和双层OTFEL器件中的应用

应用自制的聚对苯乙炔与Ａｌｑ３和Ｚｎｑ２做成单层、双层有机电致发光器件，研究了聚对苯乙炔的电致发光特性和在器件中的作用，发现了一些有意义的新现象，说明它是有机电致发光领域里极其重要的一种功能材料。     

不同空穴注入电极对有机薄膜电致发光性能的影响

成功地制备了用铝掺杂的氧化锌（ＡＺＯ）透明导电膜作阳极的有机薄膜电致发光器件，并对单层和双层结构的ＡＺＯ器件以及以两种不同ＩＴＯ作阳极器件的电致发光光谱，电流电压特性，亮度电压特性以及电致发光量子效率进行了详细的比较分析和讨论。     

有机电致发光发射材料用金属络合物研究

金属有机络合物在分析化学中有着广泛的应用。而用做发光材料还是近些年才开始的。有机电致发光（ＥＬ）材料从分子结构上区分可分为（１）有机色素（２）螯今型金属络合物（３）有机高分子，其中ＥＬ发光性能最好的则是Ａｌ￣（３＋）－８－羟基喹啉的络合物，基于这种观点本文系统地评述了螯今型金属络合物如何满足有机ＥＬ器件要求及近年来用各种金属络合物研制出的有机ＥＬ器件的进展     

8—羟基喹啉铝发光特性及老化的研究

８－羟基喹啉铝（Ｓｌｑ３）非晶薄膜发射峰同多晶粉末的发射峰启亮边的波长相同，但是非晶薄膜的发射峰比多晶粉末的发射峰红移了２０ｎｍ左右。二者的吸收光谱基本相同，说明二者的能带宽度基本相同。非晶薄膜的结构与多晶粉末不同，导致二者的导带结构不同，是二者差别的主要原因。通过地不同条件下存入的单层８－羟基喹啉铝电致发光器件的老年发现其老化的原因主要是器件工作电流的热效应引起非晶薄膜的重结晶。另外，在空气气氛     

PAA—PSF交联复合膜的制备及对低浓度有机醇水溶液反渗透分离性…

进行了ＰＡＡ－ＰＳＦ交联复合膜的制备，研究了交联剂、添加剂对膜性能的影响，并通过扫描电观察了膜的断面结构，研究了ＰＡＡ＿ＰＳＦ交联复合地低浓度有机醇类水溶液反渗透分离性能、发现对于１０００×１０＾－６乙醇水溶液截留率达到６６．２％，透过流束可达０．９×１０＾－６（ｍ＾３．ｍ＾－２．ｓ＾－１），随醇的分子量的增加，截留率不断上升，对戊醇的截留率达９４．３％，而透过流速则保持相对稳定，对不同结构醇类的     

Fe／Ag复合团簇镶嵌薄膜微观结构和磁性的研究

提出了蒸发－气体－聚集（ＥＧＡ）共沉积制备复合团簇镶嵌薄膜的新方法，并分别在方华膜和单晶Ｓｉ（１１１）衬底上制备了系列Ｆｅ／Ａｇ磁性复合团簇镶嵌薄膜样品，对所制备的样品进行了透射电镜分析，Ｘ射线能谱分析和振动样品磁强计磁性测量。结果表明，样品中Ｆｅ、Ａｇ形成了相分离，为ｆｃｃ结构的Ａｇ和ｂｃｃ结构的Ｆｅ多晶共存形态；对应于不同大小的Ｆｅ团簇样品，与块材相比，Ｆｅ团簇的晶格常数呈现出不同程度的收缩，     

高结晶度石墨薄膜结构AFM研究

制备了高结晶度石墨薄膜，并用原子力显微镜（ＡＦＭ）系统地研究其表面结构，获得了原子级分辨率的图象，观察到了扭曲的石墨晶格结构，在本文中还讨论了温度，拉伸比对薄膜结构的影响。     

Organic light emitting devices with doped electron transport and hole blocking layers

This study reports on heterostructure OLEDs with n-type molecularly doped electron transport layer and hole blocking layer. The influence of doping on the operating voltage and on light emission performances was investigated. The n-type doping molecule is 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) dispersed into either an 8-(hydroquinoline) aluminum (Alq) electron transport layer (ETL) or a 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (Bathocuproine BCP) hole blocking layer (HBL). The typical device structure is glass substrate/indium tin oxide/PEDOT/TPD–F4-TCNQ/Alq–DCM/BCP/Alq/Mg–Ag where Poly(3,4)ethylenedioxythiophene/Polystyrenesulphonate (PEDOT/PSS) is a hole injecting layer, TPD–F4-TCNQ is a hole transport layer (HTL) made of N,N′-Bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD) doped with 2 wt.% of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4-TCNQ) and Alq–DCM is the emitting layer (EML) made of Alq doped with 2 wt.% of 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) orange dye. The modified cathode consists in a combination of a BCP HBL and an Alq ETL where BCP or/and Alq were doped with PBD. Lowest operating voltage (3 V for a luminance of 10 Cd/m²) and brightest devices (6000 Cd/m²) were obtained with a hole blocking bilayer made of BCP doped with 28 wt.% deposited onto an undoped BCP (each one being 5 nm thick). Adding an undoped Alq layer improved the device current efficiency (4 Cd/A) but is detrimental to the operating voltage (6 V for a luminance of 10 Cd/m²). In the absence of real n-type doping with organic molecules, our results point out that the design of molecular doped injection layer at the cathode will need for a compromise between high luminance and efficiency on one hand and low operating voltage on the other hand.     

Tuning open-circuit voltage in organic solar cells by magnesium modified Alq(3)

The low molecular weight tris-(8-hydroxyquinoline) aluminum (Alq(3)) has been incorporated with magnesium (Mg) that altered the nature of its opto-electronic characteristics. The lowering of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) in Mg:Alq(3), compared to pure Alq(3), creates a stronger field (exceeding the exciton binding energy) at the donor-acceptor junction to dissociate the photo-generated exciton and also provides a low barrier for electron transport across the device. In an electron-only device (described in the text), a current enhancement in excess of 10(3), with respect to pure Alq(3), could be observed at 10?V applied bias. Optimized Mg:Alq(3) layer, when introduced in the photovoltaic device, improves the power conversion efficiencies significantly to 0.15% compared to the pure Alq(3) device. The improvement in the photovoltaic performance has been attributed to the superior exciton dissociation and carrier transport.     

Carbazole/triarylamine based polymers as a hole injection/transport layer in organic light emitting devices

This study examined the influence of the charge injection barriers on the performance of organic light emitting diodes (OLEDs) using polymers with a stepwise tuned ionization potential (I(p) approximately -5.01 - -5.29 eV) between the indium tin oxide (ITO) (phi approximately -4.8 eV) anode and tris(8-hydroxyquinolinato) aluminium (Alq3) (I(p) approximately -5.7 eV) layer. The energy levels of the polymers were tuned by structural modification. Double layer devices were fabricated with a configuration of ITO/polymer/Alq3/LiF/Al, where the polymers, Alq3, and LiF/Al were used as the hole injection/transport layer, emissive electron transport layer, and electron injection/cathode, respectively. Using the current density-voltage (J-V), luminescence-voltage (L-V) and efficiencies in these double layer devices, the device performance was evaluated in terms of the energy level alignments at the interfaces, such as the hole injection barriers (phi(h)(iTO/polymer) and phi(h)(polymer/Alq3)) from ITO through the polymers into the Alq3 layer, and the electron injection barrier (phi(e)(polymer/Alq3) or electron/exciton blocking barrier) at the polymer/Alq3 interface.     

Tailoring and Modifying an Organic Electron Acceptor toward the Cathode Interlayer for Highly Efficient Organic Solar Cells

With the rapid advance of organic photovoltaic materials, the energy level structure, active layer morphology, and fabrication procedure of organic solar cells (OSCs) are changed significantly. Thus, the photoelectronic properties of many traditional electrode interlayers have become unsuitable for modifying new active layers; this limits the further enhancement in OSC efficiencies. Herein, a new design strategy of tailoring the end-capping unit, ITIC, to develop a cathode interlayer (CIL) material for achieving high power conversion efficiency (PCE) in OSCs is demonstrated. The excellent electron accepting capacity, suitable energy level, and good film-forming ability endow the S-3 molecule with an outstanding electron extraction property. A device with S-3 shows a PCE of 16.6%, which is among the top values in the field of OSCs. More importantly, it is demonstrated that the electrostatic potential difference between the CIL molecule and the polymer donor plays a crucial role in promoting exciton dissociation at the CIL/active layer interface, contributing to additional charge generation; this is crucial for enhancement of the current density. The results of this work not only develop a new design strategy for high-performance CIL, but also demonstrate a reliable approach of density functional theory (DFT) calculation to predict the effect of the CIL chemical structure on exciton dissociation in OSCs.     

Organic light-emitting diodes with 2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole layer inserted between hole-injecting and hole-transporting layers

Organic light-emitting diodes (OLEDs) were fabricated based on copper phthalocyanine (CuPc) (hole-injecting layer), N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) (hole-transporting layer) and tris(8-hydroxyquinoline) aluminum (Alq₃) (emission and electron-transporting layer). A 2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole (PBD) layer was inserted between CuPc and NPB. The effect of different thickness of PBD layer on the performance of the devices was investigated. The device structure was ITO/CuPc/PBD/NPB/Alq₃/LiF/Al. Optimized PBD thickness was about 1 nm and the electroluminescent (EL) efficiency of the device with 1 nm PBD layer was about 48 percent improvement compared to the device without PBD layer. The inserted PBD layer improved charge carriers balance in the active layer, which resulted in an improved EL efficiency. The performance of devices was also affected by varying the thickness of NPB due to microcavity effect and surface-plasmon loss.     

Organic Electrofluorescent Materials Using Pyridine-Containing Macrocyclic Compounds

Novel pyridine-containing macrocyclic compounds, such as 6,12,19,25-tetramethyl-7,11,20,24-dinitrilo-dibenzo [b,m]1,4,12,15-tetra-azacyclodoc osine （TMCD）, were synthesized and used as electron transport layer in organic electroluminescent devices. Devices with a structure of glass/indium-tin oxide/arylamine derivative/ tris（quinolinolato）aluminum（Ⅲ） （Alq）/TMCD/LiF/Al exhibited green emission from the Alq layer with external quantum efficiency of 0.84% and luminous efficiency of 1.3 lm/W. The derivatives of TMCD were synthesized and characterized as well. These compounds were also found to be useful as the electron-transporting materials in organic electroluminescent devices.     

Improvement of amplified spontaneous emission performance by doping tris(8-hydroxyquinoline) aluminum (Alq3) in dye-doped polymer thin films

A well-known red fluorescent dye 4-(dicy-anomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) was codoped with an electron transport organic molecule tris(8-hydroxyquinoline) aluminum (Alq(3)) in a host matrix of polystyrene (PS), and the amplified spontaneous emission (ASE) was studied by optically pumping. It was found that the ASE performance was significantly improved by the introduction of Alq(3). The Alq(3):DCJTB:PS blending thin films showed a low threshold (2.4 microJ/pulse) and a high net gain coefficient (109.95 cm(-1)) compared with the pure DCJTB:PS system (threshold of 15.2 microJ/pulse and gain of 35.94 cm(-1)). The improvement of the ASE performance was considered to be attributable to the effective F?ster energy transfer from Alq(3) to DCJTB. Our results demonstrate that the Alq(3):DCJTB could be a promising candidate as gain medium for red organic diode lasers.     

Electroluminescence dependence on the organic thickness in ZnO nano rods/Alq3 heterostructure devices

ZnO nanorods are synthesised by a hydrothermal method on ITO glass. Their crystallization and morphology are detected by XRD and SEM, respectively. The results show that the ZnO nanorod array has grown primarily along a direction aligned perpendicular to the ITO substrate. The average height and diameter of the nanorods is about 130 nm and 30 nm, respectively. Then ZnO nano rods/Alq3 heterostructure LEDs are prepared by thermal evaporation of Alq3 molecules. The thicknesses of the Alq3 layers are 130 nm, 150 nm, 170 nm and 190 nm, respectively. The electroluminescence of the devices is detected under different DC bias voltages. The exciton emission of Alq3 is detected in all devices. When the thickness of Alq3 is 130 nm, the UV electroluminescence of ZnO is around 382 nm, and defect emissions around 670 nm and 740 nm are detected. Defect emissions of ZnO nanorods are prominent. When the thickness of Alq3 increases to over 170 nm, it is difficult to observe defect emissions from the ZnO nano rods. In such devices, the exciton emission of Alq3 is more prominent than other emissions under different bias voltage.     

Characteristics of organic light emitting diodes with copper iodide as injection layer

We have studied the use of a thin copper iodide (CuI) film as an efficient injection layer of holes from indium tin oxide (ITO) anode in a light-emitting diode structure based on tris-8-hydroxyquinoline aluminium (Alq3). The results of impedance analysis of two types of diode structures, ITO/CuI/Alq3/poly(ethylene glycol) dimethyl ether/Al and ITO/Alq3/poly(ethylene glycol) dimethyl ether/Al, are presented. Comparative analysis of their current density-voltage, luminance-voltage and impedance characteristics shows that presence of CuI layer facilitates injection of holes from ITO anode into the light-emitting layer Alq3 and increases electroluminescence efficiency of the organic light emitting diodes.