采用复合母体的高效高显色指数白光有机发光二极管

采用复合母体技术制备了一种高效率高显色指数白光有机发光二极管。驱动电压在8V到12V变化时,器件的CIE-1931色坐标由(0.3432,0.3397)变化到(0.3243,0.3218),相关色温由5035K变化到5915K,其显色指数均保持在90以上。器件在14V时达到最大亮度,为27853cd/m²,在7.5V时达到最大效率为9.58cd/A。实验中通过调节绿色和红色发光层的厚度来调节器件的发光光谱,通过敏化绿色和红色发光成分以实现电致发光效率的提高,器件的最大效率比没有采用敏化机制的参比器件提高了73.6%。     

一种基于蓝色荧光与磷光敏化技术的高显色指数白光有机电致发光器件的制备

通过采用4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi)为蓝色荧光发光单元,绿色磷光材料fac tris(2-phenylpyridine) iridium 敏化红色荧光材料4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB)为混合黄色发光单元,制备了一组白光有机电致发光器件。通过对染料掺杂浓度的优化,以及引入适当厚度的4,4-N,N-dicarbazole-biphenyl (CBP)作为中间层,获得了高效率、高显色指数的白光有机电致发光器件。器件在100 cd/m²亮度下的最高显色指数达到了90,此时的色坐标为(0.32,0.32), 非常接近白光等能点。该组器件的最大电流效率达到了11.00 cd/A,相应器件的最大亮度为13 330 cd/m²。     

A novel proposal for enhancement of light extraction efficiency in WOLEDs based on optimized photonic crystal structures

In this paper we propose a framework to enhance light extraction efficiency in white organic light emitting diodes (WOLED) using photonic crystal (PhC) structures sandwiched between indium tin oxide (ITO, n_ITO = 1.8+0.01i) and glass (n_glass = 1.51) substrate, according to the high refractive index contrast of these two layers almost 50% of the generated light inside WOLED gets trapped in the mentioned interface. The main purpose of this article is to suggest a method to intentionally optimize PhC structures to reduce total internal reflections (TIR) happening at ITO/glass interface. Here three different patterns are considered including rectangular, hexagonal and circular lattices. Using Finite Difference Time Domain (FDTD) method and the presented framework for choosing structural parameters the portion of 50% trapped light in ITO was reduced to 20% which is a large enhancement in extraction efficiency of WOLED. Also far-field results before and after adding PhCs are investigated.     

含噻二唑聚芴类白光聚合物的合成与发光性能研究

通过Suzuki偶联反应将2,7-二溴-9,9-二辛基芴（Br-DOF）、2,7-二硼酸-9,9-二辛基芴（B-DOF）和4-（8-（2,7-二溴-9-辛基芴）辛氧基）-N-4-（7-（4-（二苯胺基）苯基）苯并噻二唑）苯基-二苯胺（Br-TAF）共聚,合成了白光聚合物PDOF-TAF。以PDOF-TAF为发光层,溶液旋涂制备了非掺杂型单层白光有机电致发光二极管,色坐标为（0.23,0.18）。通过插入电子传输层TPBI和空穴传输层PVK得到的白光器件发射光谱覆盖了410~700nm区域,色坐标从（0.23,0.18）调整到（0.24,0.32）,亮度达到2020cd/m²,电流效率达到1.4cd/A。实验结果表明,PDOF-TAF是一种很好的白光聚合物发光材料,在WOLED中将有很好的应用前景。     

基于连续性掺杂的高效全荧光白色有机电致发光器件的研究

利用荧光材料PT-01, PT-86, PT-05作为黄色荧光客体, 蓝色荧光客体以及荧光母体制备了一种基于连续性掺杂结构的全荧光白光有机电致发光器件. 其发光层为主体/客体薄层/主体/客体薄层···交替蒸镀的重复单元. 通过优化发光层中主体的厚度并检测发光层中单线态激子的分布, 将黄、蓝两种客体染料生长在发光层中适当的位置, 得到了高效且光谱稳定的全荧光白光器件. 其最大电流效率为11.2 cd/A, 亮度在159–20590 cd/m²范围内色坐标仅有(±0.004,±0.005)的改变. 基于这种连续性掺杂结构制备的器件, 其性能不但可以达到传统主-客体共掺结构所制备的器件的性能,而且具有较高的可重复性, 更适合产业化大批量生产.关键词：白色有机电致发光器件连续性掺杂能量转移可重复性     

White organic light emitting diodes based on DCM dye sandwiched in 2-methyl-8-hydroxyquinolinolatolithium

Stable white electroluminescence (EL) has been achieved from organic LED, in which an ultrathin 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM) dye layer has been inserted in between two 2-methyl-8-hydroxyquinolinolatolithium [LiMeq] emitter layer and by optimizing the position of the DCM dye layer from the α-NPD/LiMeq interface. Electroluminescence spectra, current-voltage-luminescence (I-V-L) characteristics of the devices have been studied by changing the position of the dye layer. As the distance of DCM layer from α-NPD/LiMeq interface is increased, the intensity of host emission enhances rapidly. Introduction of thin layer of DCM in emissive layer increases the turn on voltage. The best Commission International de L’ Eclairage (CIE) coordinates i.e. (0.32, 0.33) were obtained with device structure ITO/α-NPD(30 nm) /LiMeq(10 nm)/DCM(1 nm)/LiMeq(25 nm)/BCP(6 nm)/Alq₃(28 nm)/LiF(1 nm)/Al(100 nm). The EL spectrum covers the whole visible spectra range 400-700 nm. The color rendering index (CRI) for our best white light (Device 4) is 47.4. The device shows very good color stability in terms of CIE coordinates with voltages. The maximum luminescence 1240 cd/m⁻² has been achieved at 19 V.     

Electroplex emission at PVK/Bphen interface for application in white organic light-emitting diodes

White organic light-emitting diode (WOLED) with a structure of ITO/poly(N-vinylcarbazole) (PVK)/4,7-diphenyl-1, 10-phenanthroline (Bphen)/tris(8-hydroxyquinoline)aluminum (Alq₃)/LiF/Al has been fabricated via the thermal evaporation technique. The electroluminescence (EL) spectrum of the as-fabricated WOLED covers from 380 to 700 nm of the visible light region with a wide blue emission from PVK and an interesting new red emission. The red emission at 613 nm in EL spectra of the WOLED was attributed to electroplex emission at PVK/Bphen interface since it was not observed in photoluminescence spectra. The WOLED showed a Commission International De l'Eclairage coordinate of (0.31, 0.32), which is very close to the standard white coordinate (0.33, 0.33).     

利用开关电源解决测色色差计的稳定性问题

国产测量仪器长期以来一直存在着稳定性与可靠性差的问题。本文针对测色色差计的稳定性与可靠性问题进行了具体的分析讨论，提出了采用开关稳压电源供电方式，以替代传统的串联性稳压电源，取得了较为理想的试验结果。本文还就开关稳压电源与传统的串联性稳压电源的优缺点进行了对比     

Reduction of guided waves in ITO/glass interface of white organic light emitting diodes (WOLEDs): Layer optimization

In this paper, our main purpose is to reduce Total Internal Reflection (TIR) phenomenon that is happening at Indium Tin Oxide (ITO, n_ito = 1.8 + 0.01i) and Glass (n_glass = 1.51) interface in WOLED to achieve higher output power. In normal WOLED because of higher refractive index contrast between ITO and Glass, guided waves usually limited into ITO layer and approximately 50% of generated light is trapped into ITO layer. Here, we tried to reduce this portion of trapped light by using 12-fold quasi-photonic crystal in mentioned interface. With some gentle changes in 12-folds structure, we could reduce TIR in this interface to less than 9%. Also, far field results before and after adding the structure were studied, which represents success of this idea and will open a new insight to lightning applications.     

Colour Appearance of Surfaces as Affected by Different Time-Varying Colour-Adaptation Sequences

We report on experiments in which observers judged colour appearance within the context of time-varying colour adaptation. We used pairs of contextual images consisting of a rapid succession of colour surfaces reproduced under different illuminants to analyse the effect of temporal colour adaptation rather than a spatial context on asymmetric matching and also to judge its influence upon the cone excitation components. We used adaptation colour distributions along the red-green and yellow-blue axes (selective conditions) and random colour distributions (non-selective condition). The results of observers’ matches for both conditions showed approximate colour-constant appearance. Although light adaptation did not fully compensate the colour changes, we obtained average colour-constancy index values of 0.6. The results for the two opponent conditions showed similar contextual effects. No significant differences between each condition were found for the L- and S-cone mechanisms and the three test illuminants. On the contrary, some degree of interaction between the comparison-field cone excitations and the colour axis can be seen when the colour mechanisms are analysed separately. This seems to be more pronounced for the S-cone mechanism and suggests that the selective condition of the adaptation sequence may well affect the observer’s chromatic matching response.     

Layer optimization in wight organic light emitting diodes (WOLEDs) to reduce the portion of guided waves in ITO/Glass interface

In this paper, our main attempt was to reduce Total Internal Reflection (TIR) happening at Indium Tin Oxide (ITO, n_ito = 1.8 + 0.01i) and Glass (n_glass = 1.51) interface, which is due to ITO's higher index in comparison with Glass's, that makes light guided in ITO layer, 50% of generated light in Wight Organic Light Emitting Diodes (WOLED) are trapped in ITO layer; here we tried to reduce this portion of trapped light by implying 12-fold quasi-photonic crystal to the mentioned interface. With some gentle changes in 12-fold's structure we could reduce TIR in this interface to less than 9%. Also, far field results before and after adding the structure to WOLED were studied, which represents suitability of using this structure for lighting applications.     

彩色视频投影机的制作

在大中专院校,自制彩色视频投影机应用于教学。     

混合型间隔层对荧磷混合式白色有机电致发光器件性能的影响

制备了基于新型蓝绿色荧光MQAB与红色磷光Ir(MDQ)2acac的荧磷混合式白色有机电致发光器件,并探讨了TPBI或UGH3两种间隔层及二者的混合间隔层的器件的发光性能.研究发现,采用TPBI和UGH3的混合间隔层可以调控载流子注入与传输的平衡.当m(TPBI)∶ m(UGH3)=1∶1时,可有效地控制发光区域,使得器件性能得到优化,并获得发光亮度高达14 700 cd/m2的白色有机电致发光器件,最高电流效率可达11.60 cd/A,且器件具有较高的色稳定性.采用混合间隔层的器件比单用TPBI或UGH3作为间隔层的器件效率提高了200％ ～ 300％.     

Non-doped phosphorescent white organic light-emitting devices with a quadruple-quantum-well structure

Non-doped white organic light-emitting devices (WOLEDs) with a quadruple-quantum-well structure were fabricated. An alternate layer of ultrathin blue and yellow iridium complexes was employed as the potential well layer, while potential barrier layers (PBLs) were chosen to be 2,2',2''-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) or N,N'-dicarbazolyl-3,5-benzene (mCP) combined TPBi. On adjusting the PBLs for device performance comparison, the results showed that the device with all-TPBi PBLs exhibited a yellow emission with the color coordinates of (0.50,0.47) at a luminance of 1000 cd/m², while stable white emission with the color coordinates of (0.36,0.44) was observed in the device using mCP combined TPBi as the PBLs. Meanwhile, for the WOLED, with a reduced efficiency roll-off, a maximum luminance, luminous efficiency, and external quantum efficiency of 12,610 cd/m², 10.2 cd/A, and 4.4%, respectively, were achieved. The performance improvement by the introduction of mCP PBL was ascribed to the well confined exciton and the reduced exciton quenching effect in the multiple emission regions.     

颜色温度和相关色温的不确定度评定方法

颜色温度和相关色温是光源的重要参量。从色品坐标(u,v)到颜色温度和相关色温的计算过程比较复杂,很难依据国际标准化组织推荐的不确定度评定方法进行分析。介绍了从光谱辐射功率和色品坐标(u,v)的不确定度出发,按照国际标准化组织的推荐方法,得到更为科学合理的颜色温度和相关色温的不确定度评定方法。针对新的国家颜色温度副基准,分别采用基于数学模型的精确方法、近似方法和几何方法对其不确定度进行了评价,并与传统方法进行了比较。采用传统方法得到的计算结果偏高,这是因为传统的计算方法很大程度上基于实验和经验估计,没有将颜色温度的不确定度与光谱辐射功率和色品坐标(u,v)的不确定度之间建立明确的数学关联,在分析过程中存在对某一不确定度源进行重复计算的可能。所述的数学推导方法相对传统方法更为科学合理。     

白光彩色联合变换相关实验中的分通道方法

提出了在彩色联合变换相关中, 使用光栅对彩色图像进行分通道处理的方法, 讨论了实现此方法对光源、滤色片的限制, 并基于此讨论提出了一种使用三色光栅图像编码的分通道解决方法。实验的结果表明, 这种方法不但降低了对光源的限制, 而且对取向不同的功率谱也便于进行分通道并行处理, 包括并行地使用零级功率谱进行彩色图像的仅形状相关。