High‐Performance Organic Electroluminescence: Design from Organic Light‐Emitting Materials to Devices

Organic electroluminescence is considered as the most competitive alternative for the future solid‐state displays and lighting techniques owing to many advantages such as self‐luminescence, high efficiency, high contrast, high color rendering index, ultra‐thin thickness, transparency, flat and flexibility, etc. The development of high‐performance organic electroluminescence has become the continuing focus of research. In this personal account, a brief overview of representative achievements in our study on the design of highly efficient novel organic light‐emitting materials (including fluorescent materials, phosphorescent iridium(III) complexes and conjugated polymers bearing phosphorescent iridium(III) complex) and high‐performance device structures together with working principles are given. At last, we will give some perspectives on this fascinating field, and also try to provide some potential directions of research on the basis of the current stage of organic electroluminescence.     

Polysilane‐Cycloimmonium Salts: New Materials for Organic Semiconductors

Summary: This work presents the first synthesis of a new polymer obtained by catalytic addition of the Si H groups of a poly[methyl(H)silane‐co‐methylphenylsilane] backbone to an N‐(allyl)cycloimmonium salt. This hybrid polymer was characterized by spectroscopic analysis, thermogravimetric analysis and gel‐permeation chromatography (GPC). The pendant N‐(allyl)cycloimmonium segments lead to the formation of molecular dipoles, as evidenced by electrical polarization experiments.

Structure of the polysilane‐cycloimmonium salt.     

Recent Advancements in and the Future of Organic Emitters: TADF‐ and RTP‐Active Multifunctional Organic Materials

Organic emitting compounds that are based on π‐conjugated skeletons have emerged as promising next‐generation materials for application in optoelectronic devices. In this Minireview, recent advances in the development of organic emitters that irradiate room‐temperature phosphorescence and/or thermally activated delayed fluorescence with extraordinary luminescence properties, such as aggregation‐induced emission, mechanochromic luminescence, and circularly polarized luminescence, are discussed.     

Phosphorus‐Containing Materials for Organic Electronics

Phosphorus‐based materials have received widespread attention in recent years, in particular as possible candidates for practical application in organic electronics. The geometry and electronic nature of phosphorus make it a favorable heteroatom for property tuning in order to obtain better performing organic electronics. This Focus Review discusses recent structural modifications and syntheses of phosphorus‐based materials, illustrates property tuning at the same time, and highlights specific examples for device applications.     

Organic Photomechanical Materials

Organic molecules can transform photons into Angstrom‐scale motions by undergoing photochemical reactions. Ordered media, for example, liquid crystals or molecular crystals, can align these molecular‐scale motions to produce motion on much larger (micron to millimeter) length scales. In this Review, we describe the basic principles that underlie organic photomechanical materials, starting with a brief survey of molecular photochromic systems that have been used as elements of photomechanical materials. We then describe various options for incorporating these active elements into a solid‐state material, including dispersal in a polymer matrix, covalent attachment to a polymer chain, or self‐assembly into molecular crystals. Particular emphasis is placed on ordered media, such as liquid‐crystal elastomers and molecular crystals, that have been shown to produce motion on large (micron to millimeter) length scales. We also discuss other mechanisms for generating photomechanical motion that do not involve photochemical reactions, such as photothermal expansion and photoinduced charge transfer. Finally, we identify areas for future research, ranging from the study of basic phenomena in solid‐state photochemistry, to molecular and host matrix design, and the optimization of photoexcitation conditions. The ultimate realization of photon‐fueled micromachines will likely involve advances spanning the disciplines of chemistry, physics and engineering.     

含硼有机发光二极管材料与器件

硼元素因其独特的价层电子结构——价电子数少于价轨道数,而拥有一个空的p轨道,其三配位化合物既可以和邻近的π体系产生有效共轭,又可以容易地与路易斯碱发生络合,形成四配位化合物。将硼元素引入传统的光电功能分子当中,往往能给整个体系带来独特的光电性质,这已成为新型有机光电功能分子设计的重要思路。本文围绕硼元素的三配位化合物和四配位化合物,从分子设计理念、化合物光电性质、相关器件的结构与效率等方面对含硼有机光电功能分子及其器件的研究进展进行综述,并对其未来发展做出展望。     

Self-Growing Organic Materials

The growth of living systems is ubiquitous. Living organisms can continually update their sizes, shapes, and properties to meet various environmental challenges. Such a capability is also demonstrated by emerging self-growing materials that can incorporate externally provided compounds to grow as living organisms. In this Minireview, we summarize these materials in terms of six aspects. First, we discuss their essential characteristics, then describe the strategies for enabling crosslinked organic materials to self-grow from nutrient solutions containing polymerizable compounds. The developed examples are grouped into five categories based on their molecular mechanisms. We then explain the mechanism of mass transport within polymer networks during growth, which is critical for controlling the shape and morphology of the grown products. Afterwards, simulation models built to explain the interesting phenomena observed in self-growing materials are discussed. The development of self-growing materials is accompanied by various applications, including tuning bulk properties, creating textured surfaces, growth-induced self-healing, 4D printing, self-growing implants, actuation, self-growing structural coloration, and others. These examples are then summed up. Finally, we discuss the opportunities brought by self-growing materials and their facing challenges.     

有机电致磷光材料的分子设计：从主体材料到客体材料

有机电致磷光器件的设计和利用，可以突破由三线态激子跃迁自旋禁阻引起的有机电致荧光器件量子效率的限制。本文综述了有机电致磷光器件和材料的研究进展，主要介绍了主体材料和客体材料的研究现状，特别是蓝光磷光器件主客体材料的研究情况。     

Advances in Organic Near‐Infrared Materials and Emerging Applications

Much progress has been made in the field of research on organic near‐infrared materials for potential applications in photonics, communications, energy, and biophotonics. This account mainly describes our research work on organic near‐infrared materials; in particular, donor‐acceptor small molecules, organometallics, and donor‐acceptor polymers with the bandgaps less than 1.2 eV. The molecular designs, structure‐property relationships, unique near‐infrared absorption, emission and color/wavelength‐changing properties, and some emerging applications are discussed.     

多功能有机及聚合物电致发光材料

有机、聚合物薄膜电致发光是近几年来国际上一个研究热点。有机、聚合物材料载流子传输能力较差,因而人们将目光转向具有载流子传输能力的多功能电致发光材料。本文主要就多功能材料的类型、合成、功能等方面作了简单介绍。     

含磷有机电致发光材料*

有机电致发光材料是有机电子学和光电信息功能材料领域的研究热点之一,在有机π共轭体系中引入杂原子是一种有效调节材料光电性能的手段。磷原子既可以通过其d轨道与π共轭体系间的σ-π相互作用来改变材料的电子结构,又具有很好的可修饰性,如被氧化、硫化或与金属配位等,从而能有效地调控材料的光电性能。因此,磷原子的引入为有机光电功能材料的分子结构设计和光电性能改善等方面的研究提供了广阔的空间,近年来得到了研究者较多的关注。本文根据引入磷原子的不同方式,综述了磷杂环戊二烯、二噻吩并磷杂环戊二烯、磷芴以及磷杂聚苯撑乙烯等材料的结构特点和在有机电致发光材料方面的研究现状,展望了含磷有机电致发光材料的应用前景和发展趋势。     

光致发绿光有机玻璃材料的研究

在氮气保护下，将配体α-噻吩甲酰三氟丙酮（HTTA）引入三异丙氧基铽中合成了铽配合物，并与甲基丙烯酸甲酯通过本体聚合制备含铽有机玻璃材料，用红外光谱（IR）、动态机械热分析（DMTA）、荧光光谱（FS）对其进行表征。结果表明，所制备的含铽有机玻璃在最佳波长激发下能发射很强的Tb^3＋离子特征绿光。DMTA测试表明，材料的玻璃化转变温度Tg、粘流温度矗及储能模量E′均比纯有机玻璃有所提高。     

有机电荷传输材料

光导体是一种重要的信息功能材料,可广泛应用于静电复印,全息照相,计算机终端仪器的激光打印,轻印刷制版等。自1938年美国人Calson^[1]等发明了利用感光导电现象的复写方式——电子照相以来,用于光导体的材料开发非常活跃。近年来,有机光导体(OPC)的实用化研究工作非常活跃,受到世人的瞩目.     

Bipolar Host Materials for Organic Light‐Emitting Diodes

It is important to balance holes and electrons in the emitting layer of organic light‐emitting diodes to maximize recombination efficiency and the accompanying external quantum efficiency. Therefore, the host materials of the emitting layer should transport both holes and electrons for the charge balance. From this perspective, bipolar hosts have been popular as the host materials of thermally activated delayed fluorescent devices and phosphorescent organic light‐emitting diodes. In this review, we have summarized recent developments of bipolar hosts and suggested perspectives of host materials for organic light‐emitting diodes.