Synthesis and properties of n-type triphenylpyridine derivatives and applications in deep-blue organic light-emitting devices as electron-transporting layer
作者:Na Li、Shiu-Lun Lai、Weimin Liu、Pengfei Wang、Juanjuan You、Chun-Sing Lee、Zengtao Liu
DOI:10.1039/c1jm11898f
日期:——
Two series of n-type triphenylpyridine derivatives with good thermal properties and efficient deep-blue emissions were designed, synthesized and systematically characterized. Most of them show high glass transition temperatures (Tg > 100 °C), relatively high electron mobilities, large ionization potentials (IP > 6.31 eV) and suitable electron affinities (EA > 2.93 eV) for facilitating efficient electron-injection. These attributes of the n-type triphenylpyridine derivatives favours their applications in organic light-emitting devices (OLEDs) as electron-transporting and hole-blocking materials (ETMs and HBMs). With these new materials, deep-blue OLEDs with a configuration of indium-tin oxide (ITO)/α-napthylphenylbiphenyl diamine (NPB)/9,10-di(2-naphthyl)anthracene (ADN)/triphenylpyridine derivative/LiF/MgAg were fabricated to investigate the properties of these triphenylpyridine derivatives as ETMs and HBMs. The devices show higher efficiency (2.54 cd A−1), and better color purity (0.15, 0.10) compared to those of similarly-structured blue OLEDs using state-of-the-art ETMs. The large IP and deep-blue emission of the triphenylpyridine derivatives are considered to be key factors for the higher efficiencies and better color purity. Optical and other properties of the compounds are discussed in terms of their molecular structures.
我们设计、合成并系统表征了两个系列的 n 型三苯基吡啶衍生物,它们具有良好的热性能和高效的深蓝色发射。它们大多具有较高的玻璃化转变温度(Tg > 100 °C)、相对较高的电子迁移率、较大的电离电位(IP > 6.31 eV)和合适的电子亲和力(EA > 2.93 eV),有利于高效电子注入。n 型三苯基吡啶衍生物的这些特性有利于它们作为电子传输和空穴阻断材料(ETM 和 HBM)应用于有机发光器件(OLED)。利用这些新材料,制备了铟锡氧化物(ITO)/α-萘基联苯二胺(NPB)/9,10-二(2-萘基)蒽(ADN)/三苯基吡啶衍生物/LiF/MgAg 构型的深蓝色 OLED,以研究这些三苯基吡啶衍生物作为 ETM 和 HBM 的特性。与使用最先进 ETM 的类似结构蓝色 OLED 相比,这些器件显示出更高的效率(2.54 cd A-1)和更好的色纯度(0.15、0.10)。三苯基吡啶衍生物的大 IP 值和深蓝色发射被认为是效率更高、色纯度更好的关键因素。本文从分子结构的角度讨论了这些化合物的光学特性和其他特性。