掺杂8-羟基喹啉铝薄膜的电致发光特性研究

在具有电致发光(EL)的有机整合染料8-羟基喹啉铝(Alq3)中接以染料罗丹明6G(R6G),用真空热蒸发的方法制备器件,获得了峰值波长575nm的黄色直流薄膜电致发光,从而通过掺杂改变了发光颜色.并在Alq3发光层不同区域插入一掺杂薄层(Alq3:R6G),利用其发光波长与未掺杂部分(Alq3)的不同,以此作为“探测层”,通过对器件光谱及电学特性的测量与分析,探讨了有关发光区域,发光机理,界面对发光影响等基本问题.     

掺杂DCJTB聚合物电化学池（LEC）的发光性质

通过在聚合物电化学池(LEC)发光器件的发光材料MEH-PPV中掺杂红光染料DCJTB,对LEC器件的发光性质进行研究。基于器件结构为ITO/MEH-PPV PEO LiCF3SO3/Al的薄膜LEC器件,其电致发光峰在570nm左右,通过在MEH-PPV与PEO的混合膜中掺杂不同比例的红光染料DCJTB,随着掺杂比例的增加,器件的发光峰由570nm向红光波段移动,通过控制DCJTB的掺杂比例制备了发光峰在570~650nm连续变化的LEC电致发光器件。对其分析认为从LEC主体发光聚合物MEH-PPV到染料DCJTB间发生了良好的能量传递。     

有机薄膜电致发光器件在反向偏压下的电致发光

合成了性能优良的聚合物--聚对苯乙烯,并采用甩胶方法制备了单层薄膜电致发光器件ITO/PPV/Al.在所制备的器件上观察到反向偏压下的电致发光现象,记录了在不同反向偏压下的电致发光光谱,测量了在反向偏压下的电流和发光强度,初步讨论了有机发光器件在反向偏压下的发光机理.     

掺杂型红色有机电致发光显示器件

全色显示是有机电致发光显示(OLED)器件发展的目标,而高性能红色发光器件一直是制约全彩色OLED器件实用化的瓶颈,也是目前有机电致发光显示研究的热点。制作了掺杂DCJTB和不同浓度的rubrene两种荧光染料的红色有机电致发光显示器件,以NPB和Alq₃分别作为空穴传输层和电子传输层,发现器件性能与只掺杂DCJTB的器件相比有明显提高,发光效率提高到2～3倍。通过Frster理论和能带理论分析了器件的能量转移机理,研究发现Frster能量转移不是掺杂器件能量转移的主要形式,载流子俘获机制才是器件效率提高的主要原因;rubrene的引入使得能量能够更有效地从Alq₃转移到DCJTB,从而显著地提高了器件的发光效率和性能。     

掺杂8－羟基喹啉铝薄膜的电致发光特性研究

在具有电致发光（ＥＬ）的有机整合染料８－羟基喹啉铝（Ａｌｑ３）中接以染料罗丹明６Ｇ（Ｒ６Ｇ）,用真空热蒸发的方法制备器件,获得了峰值波长５７５ｎｍ的黄色直流薄膜电致发光,从而通过掺杂改变了发光颜色．并在Ａｌｑ３发光层不同区域插入一掺杂薄层（Ａｌｑ３：Ｒ６Ｇ）,利用其发光波长与未掺杂部分（Ａｌｑ３）的不同,以此作为“探测层”,通过对器件光谱及电学特性的测量与分析,探讨了有关发光区域,发光机理,界面对发光影响等基本问题．     

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     

双掺杂聚合物电致发光中能量传递的光谱分析

将两种荧光染料掺杂到有机聚合物中,制作了双掺杂的电致发光器件ITO/PVK:TPB:Rubrene/LiF/Al, 得到了聚合物与两种荧光染料之间的阶梯式的能量传递。当PVK作为能量给体,Rubrene为能量受体时,能量传递不是很有效。但通过研究共掺杂体系的发光性质,发现辅助染料TPB的加入,作为能量传递的桥梁,提高了能量传递的效率,从而增加了器件的色纯度。     

利用复合色彩转换膜实现白色有机电致发光

利用蓝色有机发光二极管激发荧光色彩转换膜的方法,制备了一种新型的白色有机电致发光器件.蓝色有机发光二极管的发光层采用在4,4′-Bis(carbazol-9-yl)biphenyl(CBP)主体中掺杂高效蓝色荧光染料N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine(N-BDAVBi)来制备.有机/无机复合色彩转换膜是将有机荧光颜料VQ-D25和无机荧光粉钇铝石榴石(YAG)按一定的重量比均匀分散到-[CH3CH2COOCH3]n-(PMMA)中经涂敷、固化而成.通过与单纯有机或无机色彩转换膜的比较及调整复合转换膜本身的厚度和荧光颜料的掺杂比例来优化白光器件的发光光谱,获得了色稳定性较高的白色有机电致发光器件.当驱动电压由6V升至14V时,器件的色坐标仅在(0.354,0.304)和(0.357,0.312)之间变化,其最高电流效率约为5.8cd/A(4.35mA/cm2),最高亮度为16800cd/m2(14V).     

利用复合色彩转换膜实现白色有机电致发光

利用蓝色有机发光二极管激发荧光色彩转换膜的方法,制备了一种新型的白色有机电致发光器件.蓝色有机发光二极管的发光层采用在4,4′-Bis(carbazol-9-yl)biphenyl(CBP)主体中掺杂高效蓝色荧光染料N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine (N-BDAVBi)来制备.有机/无机复合色彩转换膜是将有机荧光颜料VQ-D25和无机荧光粉钇铝石榴石(YAG)按一定的重量比均匀分散到-[CH3CH2COOCH3]n- (PMMA)中经涂敷、固化而成.通过与单纯有机或无机色彩转换膜的比较及调整复合转换膜本身的厚度和荧光颜料的掺杂比例来优化白光器件的发光光谱,获得了色稳定性较高的白色有机电致发光器件.当驱动电压由6 V升至14 V时,器件的色坐标仅在(0.354,0.304)和(0.357,0.312)之间变化,其最高电流效率约为5.8 cd/A(4.35 mA/cm2),最高亮度为16 800 cd/m2(14 V).     

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     

Thickness effects on the optical properties of layer-by-layer poly(p-phenylene vinylene) thin films and their use in energy-modulated structures

Poly(p-phenylene vinylene) (PPV) thin films were produced by layer-by-layer (LbL) method, using soluble PPV-precursor and dodecylbenzenesulfonate salt (DBS). The amount of deposited layers strongly influences the optical properties of the thermally converted PPV film. The absorbance and luminescence spectra of ultra-thin films (consisting of only two or three PPV layers) are shifted to smaller wavelengths with respect to spectra of thicker films. This is related to the smaller average conjugation length of polymer chains, resulting in a higher HOMO-LUMO gap energy of the material. However, if a thick film is produced by repeating the deposition process and thermal conversion of ultra-thin layers, the optical spectra are still displaced to higher energies in comparison with those of thicker films produced by the conventional continuous deposition of layers. This result enabled the production of multilayered polymeric films with modulated energy profile, taking the number of deposited layers as the only variable in the manufacturing process of the structure. The aim is to guide the excitation to specific regions of the material through the Förster-type energy transfer processes. Such systems can be used at interfaces electrode/polymer and/or electrode/polymeric active layers in order to improve the performance of organic optoelectronic devices.     

聚合物O-PPV的链间相互作用的研究

近年来,聚对苯乙炔(PPV)及其衍生物作为一类性能优良的电致发光材料而受到人们的广泛关注[1].这是因为聚合物发光材料能通过化学裁剪方法来改善发光效率、颜色、成膜性等特性.载流子形成激子以及激子的辐射和非辐射衰减过程向来是聚合物发光二极管(LEDs)发光的重要环节,因此研究聚合物的光物理过程对提高器件的发光特性是非常重要的.     

聚对苯乙炔(PPV)的薄膜电致发光特性

聚对苯乙炔[poly(p-phenylene vinylene),缩写为PPV]是一种典型的线性共轭高分子.早在1968年,美国化学家Wessling就宣布合成出了PPV[1],但由于当时对该材料的应用前景不清,故未能引起科学界的重视.80年代中期,Murase等用AsF5及其它多种掺杂剂成功地对PPV进行了掺杂导电研究[2],使其电导率提高了16个数量级,由绝缘体变成了导体.     

Photoluminescence properties of new PPV derivatives

We investigate the emission properties of two copolymers by steady-state and time-resolved photoluminescence measurements. The copolymers are derived from poly-phenylene-vinylene (PPV) to which a non-conjugated ether group was added. The difference between the two copolymers is the group attached on the phenyl rings. Their fluorescence spectra present bathochromic and hypsochromic shift with respect to pristine PPV, well explained by their chemical properties. Additionally, we observe an enhancement of their quantum yield compared to that of PPV. Photoluminescence decays are bi-exponential for the two copolymers and their lifetime are longer than that of PPV. Finally, differences in emission properties between the two copolymers put in evidence the importance of their conformational structures in the luminescence processes.     

ESR and ENDOR studies of solitons and polarons in conjugated polymers

Nonlinear excitations such as solitons and polarons in conjugated polymers carry spins. In this case electron spin resonance (ESR) and electron-nuclear double resonance (ENDOR) provide unique methods to determine their wave functions. In this review article, the case of solitons in polyacetylene, CH_x, and polarons in an electroluminescent polymer, poly(paraphenylene vinylene) (PPV) are discussed as typical examples. High-resolution proton ENDOR spectra, obtained with stretch-oriented samples, yield the half extension of the excitations of 18 carbon atoms and 4 phenyl rings for CH_x and PPV, respectively. These extensions are well described by the theories in the case of finite electron correlation. In addition, light-induced ESR technique is shown to be useful in obtaining site-selective information of spin distribution in the case of PPV derivatives, as well as the excitation spectra of polarons.     

聚对苯撑亚乙烯/SiO2块状溶胶-凝胶非线性光学材料的研究

我们制作了一种由π－共轭聚合物聚对苯撑亚乙烯（PPV）均匀掺杂SiO2的块状溶胶－凝胶材料，该材料具有良好的光学品质和光学加工性能。通过扫描隧道显微镜（STM），紫外－可见吸收光谱和付氏红外光谱（FTIR）等方法研究了它的非线性光学特性。在对材料进行的光学两波耦合实验中，观察到了非对称能量耦合现象，并对此进行了分析。从吸光度和两波耦合衍射效率两方面对比了含PMMA和不含PMMA的两批不同掺杂浓度的PPV／SiO2 sol-gel材料的不同特性。     

交流电激发下的聚合物PPV单层薄膜发光器件的电致发光

交流电激发下的聚合物ＰＰＶ单层薄膜发光器件的电致发光＊张凤玲ａ，ｂ）杨志敏ａ）徐征ａ）黄宗浩ｃ）徐长远ａ）王永生ａ）徐叙王容ａ，ｂ）ａ）（北方交通大学光电子技术研究所，北京１０００４４）ｂ）（天津理工学院材料物理研究所，天津３００１９１）ｃ）（东北师...     

PPV衍生物的激发态动力学特性研究

利用共振飞秒光学克尔效应研究了C10－PPV溶液的非线性光学响应。实验结果表明，在共振激发条件下，C10－PPV挑学克尔效应信号表现为快速上升和随后的驰豫过程，其驰豫过程由两部分组成，一个200fs的快过程和一个400ps的慢过程。通过比较C10－PPV和掺杂C60后的C10－PPV荧光光谱，400ps的慢过程可归属为聚合物链内单重态激子在不同共轭段间的迁移过程。     

Preparation and photoluminescence of single conjugated polymer–TiO2 composite nanofibers

TiO₂ nanoparticles were introduced into the soluble sulfonium precursor of PPV (Poly(p-phenylene vinylene)) during the synthesis procedure of precursor. Later, PPV–TiO₂ nanofibers were prepared by electrospinning of precursor–TiO₂ solution, followed by thermal conversion. The fluorescence microscopy images showed that the resulting nanofibers exhibited outstanding emission properties. No significant differences were observed in photoluminescence spectra of PPV–TiO₂ and PPV fibers. A single oriented PPV–TiO₂ nanofiber can be obtained on the substrate by a modified electrospinning method, which is favorable for some practical applications such as electrical and optical nanodevices.