Efficient thermally activated delayed fluorescence emitters with regioisomeric effects for red/near-infrared organic light-emitting diodes

Abstract

Considerable efforts have been made to design efficient thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs). However, the development of efficient red/near-infrared (NIR) TADF materials with emission...

A red thermally activated delayed fluorescence emitter with mitigated efficiency roll-off via a π-stacked multiple donor–acceptor structure

“…S20, ESI †). [34][35][36][37][38][39][40][41][42][43][44][45] However, higher doping concentrations lead to a gradual decrease in device efficiency due to the dopant aggregation effect. Additionally, a non-doped OLED utilizing 100 wt% TCPP-DTPA demonstrates a deep red/NIR emission peak at 750 nm and an impressive EQE max of 0.55% (Fig.…”

Efficient orange and red thermally activated delayed fluorescence materials based on 1,8-naphthalimide derivatives

“…24,25 Various efforts have been made towards achieving efficient red thermally activated delayed uorescence (TADF) emitters, with the main approach being the development of strong electron acceptors. [26][27][28] The aromatic-imide group, with its rigid pconjugated structures and strong electron-withdrawing ability, has been widely used in the construction of organic semiconductors. [29][30][31] 1,8-Naphthalimide (NI) group, possessing high electron affinity and two carbonyl units, has been extensively studied for its excellent hole-blocking and electrontransporting abilities.…”

Rational Molecular Design via Cyanobenzene Integration for Constructing Efficient Yellow‐Orange Thermally Activated Delayed Fluorescence Emitters

“…Although several nitrogen-containing rigid aromatic donors such as carbazole, phenothiazine, acridine, phenazine, and phenoxazine are available for producing orange-red TADF emitters, strong and rigid acceptors with a deep LUMO are not common. [27][28][29] For example, initially, a cyano-substituted phenyl-based acceptor was reported to develop orange TADF emitters, which exhibited an EQE of up to 11%. [1] Later, several heteroatom-containing aromatic acceptors were developed, and one of the triazine-based yelloworange TADF emitters exhibited an EQE of 13.3%.…”

“…To design long‐wavelength orange‐red TADF emitters ( λem > 570 nm), strong electron donor and electron acceptor units are required to enhance the intramolecular charge transfer (ICT) character, while the energy‐gap law restricts the high radiative decay due to the internal conversion (IC) process, leading to a low PLQY. [ 23–55 ] Therefore, devising an effective molecular design to develop long‐wavelength TADF emitters is imperative. Although several nitrogen‐containing rigid aromatic donors such as carbazole, phenothiazine, acridine, phenazine, and phenoxazine are available for producing orange‐red TADF emitters, strong and rigid acceptors with a deep LUMO are not common.…”