A yellow organic emitter with novel D-A_3 architecture and hidden delayed fluorescence for highly efficient monochromatic OLEDs

摘要

A novel yellow organic emitter, namely 2,2',2 ''-nitrilotris(anthracene-9,10-dione) (NAQ3), is feasibly synthesized through one-step Buchwald-Hartiwig C-N couple reaction between 2-aminoanthracene-9,10-dione and 2-bromoanthracene-9,10-dione. The opto-electronic properties of NAQ3 are fully studied. NAQ3 exhibits the highly symmetric donor-acceptor(3) (D-A(3)) configuration, which is advantageous to the separation of its frontier orbitals. Due to the free molecular rotation, NAQ3 exhibits no delayed fluorescence in solution but it shows the delayed fluorescence in solid matrix. As a result, the OLEDs with NAQ3 as the emitter can realize the max. EQE of 13.2%.