# Smart Delayed Fluorescent AIEgens for Organic Light-Emitting Diodes: Mechanism and Adjustable Performance

## TL;DR

This review discusses how delayed fluorescent AIEgens improve OLED performance by efficiently harvesting triplet excitons.

## Contribution

The paper provides a comprehensive overview of molecular design and performance of delayed fluorescent AIEgens in OLEDs.

## Key findings

- Delayed fluorescent AIEgens enhance OLED efficiency through reverse intersystem crossing mechanisms.
- Molecular design strategies significantly influence the electroluminescent properties of OLEDs.
- Challenges remain in optimizing delayed fluorescent AIEgens for practical OLED applications.

## Abstract

Organic light-emitting diodes (OLEDs) have attracted remarkable interest in display and lighting. To effectively address triplet exciton harvesting and enhance external quantum efficiency (EQE), delayed fluorescence AIEgens have gained significant prominence. The primary luminescence mechanism involves the efficient harvesting of triplet excitons via reverse intersystem crossing (RISC) channels, categorized into three types: thermally activated delayed fluorescence (TADF), hybridized local and charge transfer (HLCT), and triplet–triplet annihilation (TTA). In this review, we summarize the recent development of doped and non-doped delayed fluorescent AIEgens-based OLEDs. This review mainly discusses the molecular design strategies and photophysical properties of delayed fluorescent AIEgens and the electroluminescent properties of OLEDs as emitting layers. Finally, the challenges and prospects of delayed fluorescent AIEgens for the fabrication of OLEDs are also briefly discussed.