Heavy-Atom-Free Room-Temperature Phosphorescent Organic Light-Emitting Diodes Enabled by Excited States Engineering

Room
temperature phosphorescence materials offer great opportunities
for applications in optoelectronics, due to their unique photophysical
characteristics. However, heavy-atom-free organic emitters that can
realize distinct electrophosphorescence are rarely exploited. Herein
a new approach for designing heavy-atom-free organic room temperature
phosphorescence emitters for organic light-emitting diodes is presented.
The subtle tuning of the singlet and triplet excited states energies
by appropriate choice of host matrix allows tailored emission properties
and switching of emission channels between thermally activated delayed
fluorescence and room temperature phosphorescence. Moreover, an efficient
and heavy-atom-free room temperature phosphorescence organic light-emitting
diode using the developed emitter is realized.