Related Experiment Video
Updated: Oct 20, 2025

Scale-up Chemical Synthesis of Thermally-activated Delayed Fluorescence Emitters Based on the Dibenzothiophene-S,S-Dioxide Core
Published on: October 24, 2017
Spiro-Based Thermally Activated Delayed Fluorescence Emitters with Reduced Nonradiative Decay for
Nidhi Sharma1,2, Michal Maciejczyk3, David Hall2,4
1Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, U.K.
Abstract:
Herein, we report the use of spiro-configured fluorene-xanthene scaffolds as a novel, promising, and effective strategy in thermally activated delayed fluorescence (TADF) emitter design to attain high photoluminescence quantum yields (ΦPL), short delayed luminescence lifetime, high external quantum efficiency (EQE), and minimum efficiency roll-off characteristics in organic light-emitting diodes (OLEDs). The optoelectronic and electroluminescence properties of SFX (spiro-(fluorene-9,9'-xanthene))-based emitters (SFX-PO-DPA, SFX-PO-DPA-Me, and SFX-PO-DPA-OMe) were investigated both theoretically and experimentally. All three emitters exhibited sky blue to green emission enabled by a Herzberg-Teller mechanism in the excited state. They possess short excited-state delayed lifetimes (<10 μs), high photoluminescence quantum yields (ΦPL ∼ 70%), and small singlet-triplet splitting energies (ΔEST < 0.10 eV) in the doped films in an mCP host matrix. The OLEDs showed some of the highest EQEs using spiro-containing emitters where maximum external quantum efficiencies (EQEmax) of 11 and 16% were obtained for devices using SFX-PO-DPA and SFX-PO-DPA-OMe, respectively. Further, a record EQEmax of 23% for a spiro-based emitter coupled with a low efficiency roll-off (19% at 100 cd m-2) was attained with SFX-PO-DPA-Me.
More Related Videos
Related Concept Videos
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
Photoluminescence: Applications
Variables Affecting Phosphorescence and Fluorescence
Fluorescence and Phosphorescence: Instrumentation
Thermal and Photochemical Electrocyclic Reactions: Overview

