Recent Advances in Polymer‐Based Metal‐Free Room‐Temperature Phosphorescent Materials

Abstract

Polymer‐based materials have evoked increasing attention in the research field of room‐temperature phosphorescence (RTP) because they can not only possess fantastic properties such as good flexibility, easy processing, low cost, high thermal stability and so forth, but also serve as rigid matrices to suppress the nonradiative decay process and thus contribute to phosphorescence emission at room temperature. This Review outlines the development of RTP in organic polymer‐based materials from the perspective of nondoped and doped polymer systems, containing the detailed photophysical properties, luminescent mechanisms and their applications. The conclusion and outlook are presented to point out the advances and challenges for further study of polymer‐based metal‐free RTP materials.

Purely Organic Crystals Exhibit Bright Thermally Activated Delayed Fluorescence

“…Since the packing of TE units within oTE‐DRZ crystal was different from that of pure TE crystal, the corresponding RTP profile of oTE‐DRZ crystal was similar but with a slight red‐shift in contrast to that of the RTP‐active TE crystal (Supporting Information, Figure S26, Table S8) . The evaluated k phos of the oTE‐DRZ crystal approached 5.2×10 1 s −1 , which was relatively fast among the reported purely organic RTP materials, and is a consequence of the strong SOC induced by the sulfur‐rich environment (Supporting Information, Figure S18) . As a result, triplet excitons from fast ISC and IC processes were well‐preserved in the “H‐aggregate”‐induced stable T 1 state .…”

Organic Room Temperature Phosphorescence Materials for Biomedical Applications

“…One is to facilitatie the intersystem crossing (ISC) from the lowest excited singlet state (S 1 ) to a triplet state (T n ) to populate the triplet excitons, and the other is to inhibit nonradiative transitions from the lowest excited triplet state (T 1 ) to the ground state (S 0 ). On the basic of these factors, researchers have proposed various strategies and methods to moldulate phosphorescent performance, such as intruduction of heavy atoms, [20][21][22] heteroatoms [23][24][25] and aromatic carbony [26][27] to boost SOC; while suppressing non-radiation of the triplet excitons by host-guest doping method [28][29][30][31] crystalization [32][33][34] and organic flameworks. [35][36][37] Therefore, developing metal-free organic luminescent materials with highly efficient room temperature phosphorescence has been becoming a hot topic in recent years.…”

Modulation of Thermally Activated Delayed Fluorescence in Waterborne Polyurethanes via Charge‐Transfer Effect

“…In order to restrain thermal quenching of triplet excitons, luminogens have to be prepared as crystals or incorporated in polymers . Waterborne polyurethane (WPU) is a kind of polymer with tunable soft and hard segments, which has a satisfactory film‐forming property and has been widely used as coatings, leathers, textiles, and matrices for functional materials .…”

“…In order to restraint hermal quenching of triplet excitons, luminogens have to be prepared as crystals or incorporated in polymers. [36][37][38][39][40][41][42] Waterbornep olyurethane (WPU) is ak ind of polymer with tunable soft and hard segments, which has as atisfactory film-formingp roperty and has been widelyu sed as coatings, [43] leathers, [44] textiles, [45] and matrices for functional materials. [46][47][48] Compared to terminal-functional polymers, like polylactides( PLAs), luminogens covalently incorporated in WPU main chain via polyadditionr eactions uffer less aggregation of luminogens in that luminogens in the main chains have smallerf ree volumes.…”