Advances in Solution‐Processed OLEDs and their Prospects for Use in Displays

Abstract

This review outlines problems and progress in development of solution‐processed organic light‐emitting diodes (SOLEDs) in industry and academia. Solution processing has several advantages such as low consumption of materials, low‐cost processing, and large‐area manufacturing. However, use of a solution process entails complications, such as the need for solvent resistivity and solution‐processable materials, and yields SOLEDs that have limited luminous efficiency, severe roll‐off characteristics, and short lifetime compared to OLEDs fabricated using thermal evaporation. These demerits impede production of practical SOLED displays. This review outlines the industrial demands for commercial SOLEDs and the current status of SOLED development in industries and academia, and presents research guidelines for the development of SOLEDs that have high efficiency, long lifetime, and good processability to achieve commercialization.

Confining donor conformation distributions for efficient thermally activated delayed fluorescence with fast spin-flipping

“…The best-performing device based on TRZ-3MCz can maintain high EQEs (EQE roll-off) of 23.8% (2.6%) and 21.5% (9.3%) at the brightness of 1000 and 3000 cd m − 2 respectively, representing the best results among the reported solution-processed TADF OLEDs and comparable with the state-of-the-art vacuum-vaporized OLEDs. 53 Moreover, the device e ciencies of the emitters TB-3MCz and TRZ-3MCz can be further improved to 26.5% and 23.8% by inserting a 10 nm PPF blocking layer with higher triplet energy, along with similarly small e ciency roll-off and high maximum brightness (Supplementary Fig. 12).…”

Engineering Colloidal Perovskite Nanocrystals and Devices for Efficient and Large-Area Light-Emitting Diodes

“…However, for the commercialization of PNC-LEDs, some remaining challenges must be overcome: Device stability. In both PNCs and PNC-LEDs, the stability is still inferior to the state-of-the-art inorganic quantum dot (QD) LEDs and to the requirements for industrial applications (retain ≥95% of initial luminance for >5,000 h) . This low operating stability in PNC-LEDs is mainly a result of ion migration upon application of an electric field, because PNCs consist of ionic crystal structures with dynamic bonding of ligands.…”

Water-Processable Self-Doped Hole-Injection Layer for Large-Area, Air-Processed, Slot-Die-Coated Flexible Organic Light-Emitting Diodes

“…sandwiched between a transparent conducting oxide-coated glass substrate and a reflective metal cathode, as shown in Figure a. The performance of SPOLEDs fabricated in academic laboratories, regarding maximum current efficiency (CE), external quantum efficiency (EQE), and operational lifetime, varies depending on the type of emitters employed and the mechanism of light emission, such as fluorescence, phosphorescence, thermally activated delayed fluorescence (TADF), or hyperfluorescence . Notably, green-emitting SPOLEDs utilizing phosphorescent and TADF emitters have achieved a maximum current efficiency (CE) of approximately 100 cd A –1 .…”

“…Notably, green-emitting SPOLEDs utilizing phosphorescent and TADF emitters have achieved a maximum current efficiency (CE) of approximately 100 cd A –1 . In contrast, red- and blue-emitting SOLEDs have achieved a maximum CE of around 10 cd A –1 . However, it is important to mention that most of these reported performance benchmarks in SPOLEDs are achieved through a hybrid approach that combines solution processing with evaporated organic layers.…”