<br>确定荧光和 TADF 有机发光二极管中水平过渡偶极子方向的关键参数,Advanced Materials

当前位置： X-MOL 学术 › Adv. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

确定荧光和 TADF 有机发光二极管中水平过渡偶极子方向的关键参数
Advanced Materials ( IF 27.4 ) Pub Date : 2021-08-02 , DOI: 10.1002/adma.202100677
Francisco Tenopala-Carmona _{1,

2} , Oliver S Lee _{1,

3} , Ettore Crovini ₃ , Ana M Neferu _{1,

3} , Caroline Murawski ₁ , Yoann Olivier ₄ , Eli Zysman-Colman ₃ , Malte C Gather _{1,

2}

Affiliation

在有机发光二极管（OLED）中，发射跃迁偶极矩（TDM）的水平方向相对于随机方向可将光出耦合效率提高多达 50%。因此，人们已经做出了广泛的努力来识别水平方向的驱动因素。发射器分子的纵横比和薄膜的玻璃化转变温度（T_g）目前被认为特别重要。然而，仍然缺乏系统的研究来确定这些参数和其他参数在多大程度上控制与最先进的 OLED 相关的各种发射器系统中的方向。本文回顾了真空加工 OLED 中荧光和热激活延迟荧光发射器分子取向的最新工作。此外，为了确定与 TDM 方向相关的参数，对 203 个已发布的发射器系统进行了荟萃分析，并与密度泛函理论计算相结合。分子量（MW）和线性是纯体系中的关键参数。在具有低 MW 发射器的主客体系统中，取向主要受主机 T_g 的影响，而发射器的长度和 MW 对于涉及高 MW 发射器的系统来说更相关。最后，给出了该领域必须向前发展才能建立分子取向综合模型的观点。

"点击查看英文标题和摘要"

Identification of the Key Parameters for Horizontal Transition Dipole Orientation in Fluorescent and TADF Organic Light-Emitting Diodes

In organic light-emitting diodes (OLEDs), horizontal orientation of the emissive transition dipole moment (TDM) can improve light outcoupling efficiency by up to 50% relative to random orientation. Therefore, there have been extensive efforts to identify drivers of horizontal orientation. The aspect ratio of the emitter molecule and the glass-transition temperature (T_g) of the films are currently regarded as particularly important. However, there remains a paucity of systematic studies that establish the extent to which these and other parameters control orientation in the wide range of emitter systems relevant for state-of-the-art OLEDs. Here, recent work on molecular orientation of fluorescent and thermally activated delayed fluorescent emitters in vacuum-processed OLEDs is reviewed. Additionally, to identify parameters linked to TDM orientation, a meta-analysis of 203 published emitter systems is conducted and combined with density-functional theory calculations. Molecular weight (MW) and linearity are identified as key parameters in neat systems. In host–guest systems with low-MW emitters, orientation is mostly influenced by the host T_g, whereas the length and MW of the emitter become more relevant for systems involving higher-MW emitters. To close, a perspective of where the field must advance to establish a comprehensive model of molecular orientation is given.

更新日期：2021-09-14

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南