Near?Infrared Light?Emitting Diodes from Organic Radicals with Charge Control

Organic radicals with fluorescence from doublet-spin energy manifolds circumvent efficiency limits singlet–triplet photophysics in organic light-emitting diodes (OLEDs). The singly occupied molecular orbital (SOMO) enables the higher potential performance. SOMO also presents substantially lower frontier orbitals compared to conventional fluorescent emitters for device operation, which can cause severe electron trapping that performance of radical OLEDs. To improve optoelectronic performance, donor–acceptor-mixed hosts are used control charge transport enhanced electroluminescence by recombination on and orbitals. (2-chloro-3-pyridyl)bis(2,4,6-trichlorophenyl)methyl-based is designed test charge-controlled architectures OLEDs transient analysis characterization studies. Efficient 4.7% maximum external quantum reported—showing substantial advances peak emission beyond 800 nm. In addition, improved at current density operation more than two orders lifetime stability achieved mixed hosts. These results enable pathways infrared-emitting devices applications ranging communications bioimaging.