Pure-organic phosphine oxide luminescent materials

Abstract

Phosphine-oxide-(PO)-based optoelectronic materials are attracting increasing attention owing to the unique advantages of P = O groups in modulating the molecular configuration, excited-state properties, and intermolecular interactions. P = O groups are also effective for the molecular design of high-performance luminescent materials. In this review, the research progress of pure-organic PO materials for light-emitting applications with high radiation is summarized. After a brief introduction about the luminescent mechanisms and the functions of P = O groups, this review focuses on the material design and structural-property relationships, especially the influences of P = O groups on the material performances, which are divided into three chapters according to the mechanisms of fluorescent (FL), thermally active delayed fluorescent (TADF), and charge-transfer-(CT)-based longafterglow materials. It was shown that the electron-withdrawing effect and the insulating character of the P = O joint could improve the electrical properties and enhance inter-and intramolecular CT without remarkably changing the emission color, making it almost 'ideal' for blue emitters. The steric hindrance of 3D PO molecules further suppressed the quenching effects for emission efficiency improvement. These superiorities guarantee that the pure-organic PO system is one of the best fluorescent materials for diverse applications.

24.4: A Linear High‐Tg Arylphosphine Oxide‐Triazine Conjugate as a Doped Electron‐Transport Material for Stable Phosphorescent OLEDs

“…Besides a LE of 91.6 cd A -1 , PE of 102.8 lm W -1 and EQE of 22.1 % @ 1000 cd m -2 , the resulting top-emission device appeared highly stable with lifetime t99 > 600 h @ 1000 cd m -2 . Together with the earlier studies, the finding reported here shall stimulate further research in the phosphine oxide derivatives for advanced optoelectronics [17,18] .…”

Role of the Intramolecular‐Locking Strategy in the Construction of Organic Thermally Activated Delayed Fluorescence Emitters with Rotation‐Restricted Acceptors

“…Since Tang and Van Slyke first proposed ultra-thin multilayer electroluminescent devices in 1987, [1] organic light-emitting diodes (OLEDs) have received significant attention from possess a strong electron-withdrawing ability and good conjugation properties, and such groups include diphenylsulfones, benzophenones, nitrogen heterocycles, cyano-benzenes, and their derivatives, which have unique molecular structures and functions. In the past decade, a number of reviews on TADF materials have been published; [11][12][13][14][15][16][17][18] however, most of these reviews mainly focused on the donor unit of TADF materials, while a few of them only summarized the progress on materials based on a specific acceptor category/group. For example, Yang et al systematically summarized the molecular designs, optoelectronic behaviors, and related applications of diazines in OLEDs, mostly focusing on the subtle structure-property relationship.…”

“…[16] Xu et al summarized the advances of pure organic phosphine-oxide-(PO)-based optoelectronic materials in lightemitting applications with high radiation efficiencies, focusing on material design and structure-property relationships, especially the effects of the P = O groups on the performance of the optoelectronic materials. [17] Yang et al comprehensively reviewed organoboron-based TADF materials based on their emission colors from blue to red-near-infrared (red-NIR), covering different molecular design strategies, photophysical properties, and optoelectronic performances in OLEDs. [18] To date, there is no review that discusses the general design strategy of acceptor units throughout their development.…”

Selective decoration of dibenzofuran with multi-donors and a triazine acceptor for triplet to singlet up-conversion

“…Many different ways of merging the donor and acceptor in the chemical platform of the TADF emitters have been exemplified in the literatures. [16][17][18][19][20][21][22][23][24][25] The most popular strategy is to link the donor and acceptor through a p-linker for high oscillator strength by extensive HOMO and LUMO overlap.…”