Deep blue to pure green boron- and nitrogen-embedded multi-resonance (MR) emitters with a binary-doped B/N skeleton have been developed that exhibit high photoluminescence quantum yields up to unity, narrow band widths (FWHM <40 nm), and fast radiative decay rates of about 108 s−1 . The materials show maximum external quantum efficiencies up to 39.8 % and CIEy coordinates of 0.05 when used as emitters in organic light-emitting diodes.
Polycyclo-heteraborin multi-resonance (MR) emitters are promising for high color-purity organic light-emitting diodes (OLEDs). Here, unlike the most common heteroatom ternary-doped (X/B/N) frameworks, a binary-doped (B/N) skeleton is reported with a large energy band for wide-range color tunability. Based on this parent-segment, a “one-pot” catalyst-free borylation method is developed which generates deep blue to pure green MR emitters from readily available starting materials, with peaks at 426–532 nm and full-width-at-half-maxima of 27–38 nm. Impressively, a maximum external quantum efficiency of nearly 40 % is recorded for the corresponding device with Commission Internationale de l′Eclairage coordinates of (0.14, 0.16), representing the state-of-the-art performances. This work presents a new paradigm and synthesis of B/N-doped MR emitters and will motivate the study of other novel frameworks.Zum Volltext