异质结型有机太阳能电池材料的最新研究进展

作为一种低耗、高效的有机光伏器件,异质结型有机太阳能电池具有成本低、重量轻、柔韧性好等优点,已引起国内外的广泛关注.设计并合成性能优良、结构新颖的有机/聚合物电子给体和电子受体材料、提高光电转换率是太阳能电池研发的关键问题之一.本文简要介绍了异质结型有机太阳能电池的特点和工作原理,从聚对苯撑乙烯衍生物、苯并噻吩类以及苯并噻二唑类聚合物三个方面系统地综述了有机太阳能电池给体材料的研究进展.同时,依据有机太阳能电池受体材料的发展历程,较全面阐述了富勒烯衍生物、9,9-联亚芴基衍生物和苝二酰亚胺衍生物三类受体材料的结构特点及其在有机光伏器件中的应用与发展.最后,对异质结型有机太阳能电池发展趋势和应用前景做了展望.     

取代基团对太阳能电池电子受体材料石墨烯衍生物导电性的影响

设计含有F,Cl,Br,OH,SO_3H,NO_2,COOH,CN或CF_3取代基团的石墨烯衍生物的结构模型,研究有机太阳能电池电子受体材料石墨烯衍生物的导电性.使用Gaussian09软件,采用密度泛函理论计算方法在B3LYP/6-31G(d)水平上,优化取代石墨烯的空间结构,计算取代石墨烯的电荷分布,考察各取代石墨烯的带隙和打开狄拉克点的难易.结果表明:在取代石墨烯接收一个电子前后,含有Br,SO_3H,CF_3或CN基团的取代石墨烯比含有F,OH,NO_2,Cl或COOH基团的取代石墨烯均具有更好的导电性,含有Br,CN或CF_3基团的取代石墨烯打开狄拉克点相对比较容易.因此,含有Br,CN或CF_3基团的取代石墨烯是较好的有机太阳能电池电子导电材料,其中Br取代石墨烯是最优的导电材料.     

基于ZnO缓冲层的有机太阳能电池数值分析

氧化锌(ZnO)材料具有良好导电性、光透性和稳定性,在光电器件中具有重要用途.利用AMPS-1D探究ZnO作为缓冲层对有机太阳能电池性能的影响.研究发现:添加ZnO缓冲层的有机太阳能电池开路电压、光电转化效率等性能有显著的提高; 电子-空穴产生率和空穴电流密度随着ZnO薄膜厚度增加而减小,而电荷态密度和电子电流密度随着ZnO薄膜厚度增加而增大.     

基于噻唑并噻唑结构的共轭聚合物太阳能电池材料的合成与表征

为了得到一种新型高效的聚合物太阳能电池材料,通过Stille聚合反应合成了一种以噻唑并噻唑为电子受体单元和硅基联噻吩为电子给体单元的交替共轭聚合物(PTTz-Si)。这种聚合物具有较窄的光学带隙(1.77eV)、较高的热稳定性以及比较宽泛的紫外可见吸收光谱,其良好的溶解性保证了可以通过溶液加工制备成有机太阳能电池器件,是一种潜在的聚合物太阳能电池活性层供体材料。通过核磁共振氢谱、碳谱、热重分析、紫外可见吸收光谱、凝胶渗透色谱和电化学等测试方法对该聚合物进行了表征,并且将聚合物与PC71CM共混制备聚合物太阳能电池器件,获取0.76%的光电转化效率。     

基于噻唑并噻唑结构的共轭聚合物太阳能电池材料的合成与表征简

为了得到一种新型高效的聚合物太阳能电池材料,通过Stille聚合反应合成了一种以噻唑并噻唑为电子受体单元和硅基联噻吩为电子给体单元的交替共轭聚合物（PTTz-Si）。这种聚合物具有较窄的光学带隙（1．77 eV）、较高的热稳定性以及比较宽泛的紫外可见吸收光谱,其良好的溶解性保证了可以通过溶液加工制备成有机太阳能电池器件,是一种潜在的聚合物太阳能电池活性层供体材料。通过核磁共振氢谱、碳谱、热重分析、紫外可见吸收光谱、凝胶渗透色谱和电化学等测试方法对该聚合物进行了表征,并且将聚合物与PC71 CM共混制备聚合物太阳能电池器件,获取0．76％的光电转化效率。     

石墨烯电极及其在有机光电子器件中的应用

石墨烯具有独特的电学性能、优异的力学性能与机械延展性、良好的热稳定性与化学稳定性,是制备高性能导电薄膜的理想替代者,石墨烯基导电薄膜及其有机半导体光电子器件研究引起了人们广泛的关注。文章主要介绍了石墨烯导电薄膜的制备以及石墨烯导电薄膜作为电极应用在有机光电子器件如有机电致发光二极管、有机太阳能电池和有机电存储器件方面的研究进展,并对石墨烯电极的应用进行了展望。     

有机太阳能电池受体材料载流子动力学的研究进展

近年来，非富勒烯有机小分子受体的出现推动了有机太阳能电池领域的蓬勃发展.然而，非富勒烯有机小分子受体的光物理机制以及基于它们的有机太阳能电池的光电转换机制仍不清楚，严重制约了高性能有机太阳能电池的高效开发.本文简要介绍了本课题组近年来在有机太阳能电池受体材料载流子动力学方面的研究进展.尝试通过研究端基工程、侧链工程和骨架工程对小分子受体载流子动力学的影响，建立结构-动力学-器件性能关系，推动有机太阳能电池的进一步发展.     

有机光伏材料与器件

正有机光伏器件是由共轭聚合物(或p-型共轭有机小分子)给体和富勒烯(或非富勒烯n-型有机半导体)受体的共混膜夹在透明导电电极和金属电极之间所组成,具有器件结构简单、制作成本低、重量轻和可制备成柔性器件等突出优点,近年来受到广泛关注,相关材料和器件的研究获得了快速发展。有机光伏器件研究的核心是提高光电能量转换效率(PCE),而提高效率的关键是拥有高效给体和受体光伏材料、高性能界面修饰层材料和新型器件结构。     

光电功能型超分子聚合物的研究进展

超分子聚合物是重复单元经超分子弱键作用链接而形成的聚集体,是功能软物质中一种新的组织方式。文中基于众多超分子聚合物的分类,重点论述主链式光电功能型超分子聚合物(optoelectronic supramolecular poly-mer,OSP)在太阳能电池、有机电致光、电致变色等得到深入研究领域的应用进展;通过调控能量转移、电荷转移、载流子迁移率等可以实现OSP的白光、光电转换、电致变色等性质和相关器件,并使OSP日渐成为超分子化学与有机电子等学科交叉领域研究的新热点;最后展望了OSP的研究趋势。     

石墨烯基墨水的制备及其在印刷电子中的应用

 石墨烯材料具有优异的导电性、柔性、化学稳定性等特征,在印刷电子领域中具有广阔的应用前景。概述了石墨烯材料的宏量制备方法,结合喷墨打印、丝网印刷和3D打印等方法介绍了石墨烯墨水制备的技术特点和要求,展示了石墨烯在印刷电子功能器件中的应用,主要类型包括透明导电薄膜、柔性电路、超级电容器和可穿戴传感器等。总结了该领域当前研究进展中存在的问题和挑战,从材料设计、加工制备和器件应用方面进行了展望。在未来发展中可通过丰富石墨烯打印线路的结构形式,并注重利用组装的策略增强结构有序性,实现多功能、高性能的器件制备和应用。     

Recent development of organic electron transport materials

This article reviews the recent development of organic electron transport materials applied in the fields of organic photoconductors, light-emitting diodes, field-effect transistors and solar cells. Several technologies for charge carrier mobility measurement are summarized and compared, and a series of basic principles for designing high-performance organic electron transport materials are suggested as well.     

Photo-functional materials based on copper(Ⅰ) complexes

Copper(Ⅰ) complexes are attractive photo-functional materials due to their rich photochemical and photophysical properties. It has been proved that these new materials have potential application in many fields, such as organic light-emitting diodes, optical sensor, nonlinear optics and dye sensitized solar cells. The goal of this review is to outline the progress in this field. Many aspects, including new ligands, stereochemical control and the construction of supramolecules, design of the excited states, the high-energy emission and low-energy emission, the Cu-Cu bonding interactions and applications, are discussed.     

Efficient organic photovoltaic diodes based on doped pentacene

Recent work on solar cells based on interpenetrating polymer networks and solid-state dye-sensitized devices shows that efficient solar-energy conversion is possible using organic materials. Further, it has been demonstrated that the performance of photovoltaic devices based on small molecules can be effectively enhanced by doping the organic material with electron-accepting molecules. But as inorganic solar cells show much higher efficiencies, well above 15 per cent, the practical utility of organic-based cells will require their fabrication by lower-cost techniques, ideally on flexible substrates. Here we demonstrate efficiency enhancement by molecular doping in Schottky-type photovoltaic diodes based on pentacene--an organic semiconductor that has received much attention as a promising material for organic thin-film transistors, but relatively little attention for use in photovoltaic devices. The incorporation of the dopant improves the internal quantum efficiency by more than five orders of magnitude and yields an external energy conversion efficiency as high as 2.4 per cent for a standard solar spectrum. Thin-film devices based on doped pentacene therefore appear promising for the production of efficient 'plastic' solar cells.     

n-type colloidal semiconductor nanocrystals

Colloidal semiconductor nanocrystals combine the physical and chemical properties of molecules with the optoelectronic properties of semiconductors. Their colour is highly controllable, a direct consequence of quantum confinement on the electronic states. Such nanocrystals are a form of 'artificial atoms' (ref. 4) that may find applications in optoelectronic systems such as light-emitting diodes and photovoltaic cells, or as components of future nanoelectronic devices. The ability to control the electron occupation (especially in n-type or p-type nanocrystals) is important for tailoring the electrical and optical properties, and should lead to a wider range of practical devices. But conventional doping by introducing impurity atoms has been unsuccessful so far: impurities tend to be expelled from the small crystalline cores (as observed for magnetic impurities), and thermal ionization of the impurities (which provides free carriers) is hindered by strong confinement. Here we report the fabrication of n-type nanocrystals using an electron transfer approach commonly employed in the field of conducting organic polymers. We find that semiconductor nanocrystals prepared as colloids can be made n-type, with electrons in quantum confined states.     

两类异质结构中光生电荷分离效率与光电性质

首先制备Cu4Bi4S9纳米带与石墨烯不同比例复合体系(CBS-graphene),其中石墨烯质量分数分别为:0.4%,0.8%,1.2%,1.6%,2.0%和2.4%.以α-Fe_2O_3为电子受主,CBS和CBS-graphene为电子施主,制备成α-Fe_2O_3/CBS、α-Fe_2O_3/CBS-graphene两类异质结构及体相异质结太阳能电池.XRD检测结果表明,异质结两组分都达到了良好的结晶状态;而且,两类复合体系都呈现出了复合结构的光吸收特性,但光吸收性质无明显差异.对于CBS-graphene,随着石墨烯含量逐步增加其光伏性质逐渐增强,当石墨烯质量分数为1.6%时达到最佳光伏响应强度,此后其光伏性质逐渐减弱.稳态和电场诱导表面光电压谱表明两类异质结都具有优越的光伏性质,但α-Fe_2O_3/CBS-graphene呈现出明显优于α-Fe_2O_3/CBS的光伏响应.基于石墨烯质量分数为1.6%,α-Fe_2O_3/CBS和α-Fe_2O_3/CBS-graphene两类体相异质结太阳能电池最高光电转换效率分别为3.1%和6.8%.从异质结厚度、能级匹配、石墨烯导电网络以及优越的电子传输特性几个方面,详细讨论了光生电荷分离的影响因素及光生电荷传输动力学.     

Unique synthesis of graphene-based materials for clean energy and biological sensing applications

Graphene has unique physical properties,and a variety of proof-of-concept devices based on graphene have been demonstated.A prerequisite for the application of graphene is its production in a controlled manner because the number of graphene layers and the defects in these layers significantly influence transport properties.In this paper,we briefly review our recent work on the controlled synthesis of graphene and graphene-based composites,the development of methods to characterize graphene layers,and the use of graphene in clean energy applications and for rapid DNA sequencing.For example,we have used Auger electron spectroscopy to characterize the number and structure of graphene layers,produced single-layer graphene over a whole Ni film substrate,synthesized well-dispersed reduced graphene oxide that was uniformly grafted with unique gold nanodots,and fabricated graphene nanoscrolls.We have also explored applications of graphene in organic solar cells and direct,ultrafast DNA sequencing.Finally,we address the challenges that graphene still face in its synthesis and clean energy and biological sensing applications.     

应变调控柔性电子器件磁电性质的研究进展

柔性电子器件具有独特的形状可塑性,因而引起了人们极大的研究热情.柔性电子器件在未来或将成为下一代电子器件的重要分支,在电子显示、二极管、生物医疗器件、太阳能电池等领域有着广阔的发展前景.近些年,许多研究人员将柔性技术与自旋电子学相结合,开始探索应变对于生长在柔性衬底上的磁电异质结磁电性质的影响,通过改变柔性衬底的曲率等手段调控器件的磁电效应.相关基础研究为磁存储器、磁传感器、非易失性阻变存储器等电子器件的研究开辟了新思路.     

Improving the performance of doped pi-conjugated polymers for use in organic light-emitting diodes

Organic light-emitting diodes (OLEDs) represent a promising technology for large, flexible, lightweight, flat-panel displays. Such devices consist of one or several semiconducting organic layer(s) sandwiched between two electrodes. When an electric field is applied, electrons are injected by the cathode into the lowest unoccupied molecular orbital of the adjacent molecules (simultaneously, holes are injected by the anode into the highest occupied molecular orbital). The two types of carriers migrate towards each other and a fraction of them recombine to form excitons, some of which decay radiatively to the ground state by spontaneous emission. Doped pi-conjugated polymer layers improve the injection of holes in OLED devices; this is thought to result from the more favourable work function of these injection layers compared with the more commonly used layer material (indium tin oxide). Here we demonstrate that by increasing the doping level of such polymers, the barrier to hole injection can be continuously reduced. The use of combinatorial devices allows us to quickly screen for the optimum doping level. We apply this concept in OLED devices with hole-limited electroluminescence (such as polyfluorene-based systems), finding that it is possible to significantly reduce the operating voltage while improving the light output and efficiency.     

具有聚集诱导发光性能的四苯乙烯酰胺衍生物的合成与性能研究

文章将四苯乙烯基与己氧基苯通过酰胺键连接起来,合成了四苯乙烯酰胺衍生物。主要利用紫外-可见吸收光谱仪、荧光光谱仪、热重分析仪、示差扫描量热仪、扫描电镜、热台偏光显微镜等表征手段对该衍生物的光物理性能、热性能、聚集诱导发光性能和自组装行为进行了研究。研究结果表明,所合成的化合物在紫外光激发下发射强烈的蓝色荧光;其热失重温度达到359℃,显示出较高的热稳定性;化合物样品在熔融和冷却过程中均能观察到明显的液晶织构,说明其具有明显的液晶性;化合物分子在不同的溶剂组成中可自组装形成棒状或球状形貌不同的聚集体结构。     

新型铅卤基钙钛矿材料及其应用

铅卤基钙钛矿材料因其优异的光电转化效率、可调禁带宽度、较高载流子迁移率、较大光吸收系数等突出性能,在太阳能电池、发光器件和光电探测等领域获得广泛关注。介绍了铅卤基钙钛矿薄膜、量子点和单晶的制备和相关物理性能,总结了其在太阳能电池、发光二极管(LED)、光电探测器等领域的最新研究进展,讨论了目前存在的问题及未来发展前景。