Related Experiment Video
Updated: Jan 23, 2026

Development of Efficient OLEDs from Solution Deposition
Published on: November 4, 2022
Exciplex System with Increased Donor-Acceptor Distance as the Sensitizing Host for Conventional Fluorescent OLEDs
Xiaozeng Song, Dongdong Zhang, Haoyuan Li1
1School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics (COPE) , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States.
Abstract:
Exciplex systems with efficient thermally activated delayed fluorescence as the sensitizing hosts for fluorescent organic light-emitting diodes (OLEDs) have been flourished recently, while the device performances are still lagging behind. Here, a donor molecule sterically encapsulated with tert-butyl units is designed and synthesized to increase the donor-acceptor separation in an exciplex system, leading to reduced singlet-triplet energy gap (Δ ESTs) and improved reverse intersystem crossing (RISC) efficiency. OLEDs utilizing exciplexes with increased donor-acceptor distance ( rDA) as the hosts for conventional fluorescent dopants exhibit a maximum external quantum efficiency (EQEmax) as high as 16.5%, benefiting from the enhanced RISC process and suppressed exciton loss by the Dexter interaction. Furthermore, extremely low efficiency roll-off is obtained with EQEs of 16.2% at 5000 cd/m2 and 15.2% at 10 000 cd/m2. The results here represent the state-of-the-art performances for devices based on exciplexes as the hosts for conventional fluorescent dopants, manifesting the superiority of exciplexes with increased rDA as the sensitizing hosts for fluorescent dopants.
Related Concept Videos
Distance Problem
Rolling Without Slipping
Rolling With Slipping
An object's rolling motion is characterized by its rotation around its axis, while linear motion refers to the object's translational motion along a surface. Frictional forces can...
Distance Corrections
The Distance Formula
Short-distance Transport of Resources

