有机小分子及金属有机配合物电子传输材料的研究进展

概述了有机小分子及金属有机配合物电子传输材料的研究进展,对由小分子电子传输材料构成的有机电致发光器件的发光性能、发光效率等方面进行了比较,并对小分子材料的研究前景进行了展望.     

钙钛矿太阳能电池中电子传输层研究进展

近年来钙钛矿太阳能电池发展迅速,电子传输层在传输电子和阻挡空穴等方面起着重要作用,是钙钛矿太阳能电池效率提高的保障.文章从电子传输层的工作机理出发,介绍了目前常见的金属氧化物和有机分子材料作为电子传输材料的相关研究进展,综述了针对电子传输层的离子掺杂、界面修饰、纳米结构调整等方面的研究工作,对电子传输层今后的研究趋势进行展望.     

高效蓝色有机发光材料与器件

有机半导体由于具有柔软性而可卷曲成形,具有可溶加工性而采用印刷成膜,从而使得加工成本有可能大大降低而受到广泛关注．本文针对有机发光材料中n型材料不足及宽能带与高电子传输性不可同时实现的难题,我们设计与合成了一系列的宽带电子传输材料并应用于蓝色磷光器件,实现了将近100％的内量子效率蓝色磷光．针对蓝色发光材料色度不纯的问题,我们设计了深蓝色荧光材料,其器件色度坐标CIE（0．15,0．08）,与NTSC标准蓝光相当接近,同时实现接近理论极限的外量子效率发光．针对器件中由于平面波导及表面等离激元等能量模式的损失,我们利用有机材料的自团聚现象在有机发光器件金属阴极上制备无规的纳米结构,把束缚能量转化成自由光子,使得顶出光效率提高到2．1—2．7倍,且不改变原有器件的发光光谱形状．     

基于ZnO材料的有机-无机杂化太阳电池的光伏性能优化

有机-无机杂化太阳电池是一种由提供电子的有机聚合物和接受电子的无机半导体构成的新型电池,常用的无机半导体材料有纳米氧化锌（ZnO）、二氧化钛（TiO₂）、硫化镉（CdS）等。杂化太阳电池在研究过程中存在一些问题,如电池中电子传输效率差、太阳能利用率低、无机半导体和有机聚合物之间化学不兼容以及由此导致的光电转换效率低等。围绕这些问题,针对以ZnO半导体材料为电子受体的太阳电池,从电子受体材料形貌、电子给体材料种类以及添加不同修饰层等方面论述了电池光伏性能的优化方法,对该电池的未来发展趋势进行了展望。电池性能的优化,为低成本、高效率应用该类杂化太阳电池带来了希望。     

一种新型有机电子传输材料

报道新型有机电子传输材料N-乙基-4-乙酰氨基萘亚胺及其在有机电致发光器件中的电子传输性．     

ZnO/Cs2CO3双电子传输层有机太阳能电池

有机太阳能电池的异质结界面是影响其性能的一个重要因素.以氧化锌/碳酸铯作为双电子传输层,改善电子传输层与活性层的界面接触并提高电子传输能力.利用溶胶-凝胶法制备OSCs器件,通过优化的双电子传输层,使基于PTB7-Th:PC₇₁BM的OSCs器件的最高效率达到了8.08%,其相较于ZnO电子传输层器件提高了10.68%.实验表明,由于ZnO/Cs₂CO₃ ETLs具有最佳的表面形貌和光吸收,其填充因子、短路电流密度和电子迁移率都显著提升.这种ZnO/Cs₂CO₃双电子传输层为OSCs性能改善提供了新的思路.     

Free-electron-like dispersion in an organic monolayer film on a metal substrate

Thin films of molecular organic semiconductors are attracting much interest for use in electronic and optoelectronic applications. The electronic properties of these materials and their interfaces are therefore worth investigating intensively, particularly the degree of electron delocalization that can be achieved. If the delocalization is appreciable, it should be accompanied by an observable electronic band dispersion. But so far only limited experimental data on the intermolecular dispersion of electronic states in molecular materials is available, and the mechanism(s) of electron delocalization in molecular materials are also not well understood. Here we report scanning tunnelling spectroscopy observations of an organic monolayer film on a silver substrate, revealing a completely delocalized two-dimensional band state that is characterized by a metal-like parabolic dispersion with an effective mass of m* = 0.47m(e), where m(e) is the bare electron mass. This dispersion is far stronger than expected for the organic film alone, and arises as a result of strong substrate-mediated coupling between the molecules within the monolayer.     

一个飞速发展的领域:非富勒烯有机太阳能电池受体材料

有机太阳能电池作为解决能源问题的重要手段之一,2006年以来得到了深入的研究.其电子受体材料较多地局限在富勒烯及其衍生物领域,由于其光谱吸收窄、溶解性差、成本高、生产过程中环境不友好等问题,迫使科学家们寻找新的受体材料.近年来,非富勒烯电子受体材料吸引了科学家们的关注.非富勒烯受体材料的光谱吸收宽,溶解性好,结构可控,易加工等特点决定了其在有机太阳能电池领域有广泛的应用.综述了2011年以来非富勒烯有机太阳能电池受体材料领域的进展,并对其将来的发展进行了展望.     

二噻吩并[3,2-b:2',3'-d]噻吩-2-羧酸的微区结构及光电子传输特性

利用溶剂引导相转变的方法制备了二噻吩并[3,2-b:2',3'-d]噻吩-2-羧酸(DTTDA)自组织薄膜.利用原子力显微镜(Atomic Force Microscopy, AFM)、紫外可见(Ultra Violet-Visible,UV-Vis)吸收光谱、荧光光谱和导电原子力显微镜(Conductive Atomic Force Microscopy, C-AFM)对其成膜性能及光电子传输性能进行研究.研究结果表明:该化合物成膜性能较好,在成膜过程中分子间具有很强的相互作用,易形成紧密聚集的平整薄膜.由于该分子间易于产生较紧密的聚集,使得其具有较高的电子传输特性.因此,该化合物可望作为有机电致发光器件的候选材料.     

Effective adjustment of the optoelectronic properties of organic conjugated materials by synthesizing <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">n</Emphasis> diblock molecules

Because organic conjugated materials offer several advantages relative to their inorganic counterparts,the development of organic conjugated materials has been one of the most active research areas in optoelectronic materials.For almost two decades,the search for organic conjugated materials has represented a major driving force for research concerned with controlling the band gap of extended π-conjugated molecules.In particular,among the parameters affecting the performance of organic light-emitting diodes (OLEDs),the energy levels of organic conjugated materials play an important role because they can affect the driving voltage,wavelength,efficiency,and lifetime of the final device.Balanced injection and transport of electrons and holes are therefore crucial for achieving OLEDs with high quantum efficiency.In this regard,research into adjusting the energy levels of organic conjugated materials is very meaningful for the development of OLEDs.To adjust the energy levels of the organic conjugated materials,Huang et al.have presented a new molecular design and synthesis route that yields p-n diblock conjugated copolymers and oligomers.The present review summarizes and analyzes the progress on adjusting the optoelectronic properties of organic conjugated materials that is due to synthesizing p-n diblock molecules.We discusses primarily work done by Huang et al.,but also discusses work done elsewhere over the past few years.We also point out issues that require attention,and highlight hot spots that require further investigation.     

Bipolar charge transport property of N,N′-dicarbazolyl-1,4-dimethene-benzene: A study of the short range order model

Short range order model is commonly used to explain the charge transport property of disordered organic semiconductors.However,its validity is not yet studied.In this paper,the hole and electron mobilities of a bipolar material,N,N’-dicarbazolyl-1,4dimethene-benzene(DCB),were measured through time of flight method.The hole and electron mobilities of DCB based on the crystalline structure were calculated.In order to investigate the short range order model,the ratios of charge mobilities at zero electric field of holes to electrons were calculated.The results showed that this model cannot fully explain our case.The reason was discussed in detail,and a correction method was proposed.We showed that using the short range order model without preconditions to explain the charge transport property of amorphous materials may lead to deviations,which is often neglected in the past.     

输运层厚度与迁移率对双层有机发光器件性能的影响

基于一些合理假设与近似,建立了具有欧姆接触载流子注入的双层有机电致发光器件的解析模型．模型中计算参数只有空穴和电子输运层的厚度、迁移率、外加电压及材料参数Fh和Fe,且这些参数都是可以通过测量得到的．研究了材料参数Fh,Fe对器件复合电流密度的影响及空穴输运层厚度和载流子迁移率对器件电场强度和复合电流密度的影响．结果表明：空穴输运层厚度和载流子迁移率引起电场强度的重新分布,进而对复合电流密度产生影响;接触限制电极注入少数载流子的器件可以取得比欧姆接触注入多数载流子的器件更高的复合电流．     

Ionic Transfer in Hybrid Inorganic/Organic Membranes

1 Results In last years increasing interest has been devoted to the development and research of transport properties of hybrid organic/inorganic membranes. Traditionally, these membranes are used as electrolyte in fuel cells. However a number of their properties allow considering them as perspective materials for water treatment and substance purification. In this work transport properties of some ion exchange membranes modified by inorganic nanoparticles (hydrated oxides or solid acids) are discussed. ...     

石墨烯在光电器件中的应用

 讨论了近年来石墨烯在太阳能电池、有机发光二极管以及场致发射器件方面的应用研究。石墨烯是碳的同素异形体的一种,是二维的薄膜材料,具有独特的导电特性及机械弯曲性能,可以作为太阳能电池、有机发光器件的柔性电极;石墨烯与有机聚合物材料复合可以形成大的给体受体界面,有利于太阳能电池中激子的扩散速率、载流子迁移率的提高,可以作为有机太阳能电池的电子受体材料;石墨烯具有一维尖锐的刀口状边缘,具有大的电场增强系数,同时由于石墨烯自身的良好导电能力,可以作为场致发射器件中的电子传导与电场发射材料。石墨烯在光电器件中应用的深入研究有望突破目前光电技术的发展瓶颈,是一个极具前景的新研究领域。     

准一维强关联梯子型材料反常的输运性质

在t-J模型下，应用Fermion—spin理论研究了准一维强关联梯子型材料的输运行为．研究结果表明，这类材料中电子的带电自由度和自旋自由度相分离成为带电的ho1on和不带电的spinon，而反常的输运性质主要是由ho1ons的散射而决定，同时梯子型材料中2条链之间的强的量子干涉作用可以导致输运性质偏离一维系统的输运行为．     

Nanoscale Morphology Control in Functional Polymer Systems

1 Results In high-performance organic solar cells,the photoactive layer consists of a blend of an electron donor and an electron acceptor constituent,a so-called bulk heterojunction.The requirements to morphology of the efficient photoactive layer are nanoscale phase separation,which provides large interface area for exciton dissociation,and at the same time continuous pathways for transport of free charge carriers to the appropriate electrodes.In this context,the research is now focused on a better und...     

半导体纳米材料CdSe/ZnS在显示器件中的应用

以半导体纳米材料CdSe/ZnS作为发光层, ZnO作为电子传输层, 用Al和氧化铟锡（ITO）分别作为两极材料, 采用旋涂和真空蒸镀膜技术制备半导体发光二极管, 并对其光学性质进行表征. 结果表明: 该器件发射黄光, 峰位为575 nm, 半峰宽30 nm, 最大发光强度2 000 cd/m²; 在较高的电流密度下, 该器件的电致发光效率无
明显衰减; 当半导体纳米材料CdSe/ZnS及ZnO分别作为发光层和电子传输层时, 可制备具有高电流密度且稳定的发光二极管主体材料.     

顶发射白光有机电致发光器件的优化

为满足大面积固态照明与全彩显示的需求,实现色度稳定的高效率顶发射白光有机电致发光器件,采用仿真和实验相结合的研究方法,模拟基于光学传输矩阵法和电磁场理论进行计算,用真空蒸镀法制备器件并测试其光电性能。确定传输层材料、厚度和结构,优化发光效率,逐步改进发光层结构,以改善器件的效率和颜色质量。结果表明,基于电学平衡的P-I-N传输结构和蓝/红/蓝三明治型发光结构,能实现色度稳定的高效率顶发射白光有机电致发光器件。     

A soluble and air-stable organic semiconductor with high electron mobility

Electronic devices based on organic semiconductors offer an attractive alternative to conventional inorganic devices due to potentially lower costs, simpler packaging and compatibility with flexible substrates. As is the case for silicon-based microelectronics, the use of complementary logic elements-requiring n- and p-type semiconductors whose majority charge carriers are electrons and holes, respectively-is expected to be crucial to achieving low-power, high-speed performance. Similarly, the electron-segregating domains of photovoltaic assemblies require both n- and p-type semiconductors. Stable organic p-type semiconductors are known, but practically useful n-type semiconductor materials have proved difficult to develop, reflecting the unfavourable electrochemical properties of known, electron-demanding polymers. Although high electron mobilities have been obtained for organic materials, these values are usually obtained for single crystals at low temperatures, whereas practically useful field-effect transistors (FETs) will have to be made of polycrystalline films that remain functional at room temperature. A few organic n-type semiconductors that can be used in FETs are known, but these suffer from low electron mobility, poor stability in air and/or demanding processing conditions. Here we report a crystallographically engineered naphthalenetetracarboxylic diimide derivative that allows us to fabricate solution-cast n-channel FETs with promising performance at ambient conditions. By integrating our n-channel FETs with solution-deposited p-channel FETs, we are able to produce a complementary inverter circuit whose active layers are deposited entirely from the liquid phase. We expect that other complementary circuit designs can be realized by this approach as well.     

利用有源层掺杂提高有机发光

通过对电子传输层和空穴传输层的共同掺杂，达到提高有机发光二极管（DLED）电流效率的目的。与常规的在电子传输层中掺杂有机染料的掺杂器件相比，本实验是在Alq(电子传输层材料）与NPB（空穴传输层材料）形成的均匀互掺有源层中，再掺杂染料Rubrene。此种结构，其有源层能有效地限载流子而增加电子和空穴载流子相遇的几率，进而提高复合效率，使电流效率明显提高。同时，有源层的连续生长避免了有机层间界面的形成，改善了器件的稳定性。比较此结构器件与常规掺杂器件的特性，并对其发射机理进行讨论。