Related Experiment Video
Updated: Aug 9, 2025
05:51
Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes
Published on: November 15, 2016
8.1K
Efficient Circularly Polarized Electroluminescence from Achiral Luminescent Materials
Letian Xu1, Hao Liu1, Xiaoluo Peng1
1State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China.
Angewandte Chemie (International Ed. in English)
|February 24, 2023
Summary
Researchers developed new near ultraviolet circularly polarized (CP) luminescent materials. These materials enable efficient CP electroluminescence (CP-EL) in organic light-emitting diodes (OLEDs) using common achiral emitters.
Area of Science:
- Materials Science
- Organic Electronics
- Photophysics
Background:
- Circularly polarized electroluminescence (CP-EL) typically requires specialized circularly polarized luminescent (CPL) materials.
- Achiral luminescent materials are generally not considered capable of direct CP-EL generation.
- Developing efficient CP-EL from readily available materials remains a significant challenge in organic light-emitting diodes (OLEDs).
Purpose of the Study:
- To develop near ultraviolet (UV) CPL materials capable of inducing CP-EL in achiral emitters.
- To demonstrate a universal and simple method for achieving efficient CP-EL in OLEDs.
- To explore the use of these new CPL materials as emitters, hosts, or sensitizers for various achiral luminescent materials.
Main Methods:
- Synthesis and characterization of near ultraviolet CPL materials with high photoluminescence quantum yields and CPL dissymmetry factors.
- Fabrication of CP-OLEDs using the developed CPL materials as emitters.
- Integration of the CPL materials as hosts or sensitizers with commercially available yellow-orange phosphorescence, thermally activated delayed fluorescence (TADF), and multi-resonance (MR) TADF materials.
Main Results:
- Developed near UV CPL materials successfully induced blue to red CP-EL in various achiral luminescent materials.
- Achieved strong near UV CP-EL with high external quantum efficiencies (ηext) up to 9.0% and minimal efficiency roll-off when used as emitters.
- Generated intense CP-EL with high dissymmetry factors and outstanding ηext up to 30.8% when used as hosts or sensitizers for achiral emitters.
Conclusions:
- The developed near UV CPL materials provide a simple and universal pathway to efficient CP-EL.
- This approach overcomes the limitations of using specialized CPL materials, enabling CP-EL from common achiral emitters.
- The findings pave the way for broader applications of CP-EL in displays, lighting, and 3D-coupled systems.
Related Concept Videos
01:14Photoluminescence: Applications
463
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
463
02:24Properties of Enantiomers and Optical Activity
17.3K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
17.3K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.9K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.9K