Multi-resonance emitters with room-temperature phosphorescence in amorphous state and excited by visible light.

Unlike boron, nitrogen-containing multi-resonance emitters with thermally activated delayed fluorescence, here we report boron, sulfur (B, S)-based multi-resonance emitters with room-temperature phosphorescence (RTP) by inserting thiophene into a 5,9-dithia-13-boranaphtho[3,2,1-]anthracene skeleton that simultaneously realizes large singlet-triplet energy splitting and strong spin-orbital coupling, leading to efficient room-temperature phosphorescence in an amorphous state. Unlike most RTP emitters with ultraviolet excitation, the multi-resonance RTP emitters exhibit strong phosphorescence under daily-use blue/white LED lamps owing to their intense absorption in the visible-light region (400-486 nm). Meanwhile, such RTP behavior can be tuned by the number and fusing pattern of the thiophene moieties, with the emitters containing thiophene linked to boron atoms α-positions exhibiting bathochromatically shifted emissions and longer phosphorescence lifetimes (47.

Through-space charge transfer dendrimers employing oxygen-bridged triarylboron acceptors for efficient deep-blue electroluminescence.

Through-space charge transfer dendrimers consisting of dendritic triacridan donors and oxygen-bridged triarylboron acceptors are demonstrated to exhibit deep-blue thermally activated delayed fluorescence with the state-of-the-art external quantum efficiency of 14.6% for electroluminescence by a solution process.