Near-ultraviolet
(NUV) light-emitting pure organic fluorophores
are crucial in organic electronics because of less power consumption
and full-color displays with a wide color gamut. However, emerging
solution-processable NUV emitters for violet organic light-emitting
diodes (VOLEDs) is quiet a formidable task. On this basis, two efficient
NUV/deep blue N,N-diphenyl-3′-(1-(3-(trifluoromethyl)phenyl)-1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1′-biphenyl]-4-amine
(3-PIMCFTPA) and 3′-(4,5-diphenyl-1-(3-(trifluoromethyl)phenyl)-1H-imidazol-2-yl)-N,N-diphenyl-[1,1′-biphenyl]-4-amine
(3-BICFTPA) emitters were designed and synthesized based
on a meta-linking D−π–A design strategy, which
efficiently shortens the π-conjugation length, which results
emission in the higher energy end of the emitters. Experimental and
theoretical investigation reveals materials with efficient NUV emission
and good bipolar carrier transporting properties. Hence, the undoped,
as well as doped OLED devices, were fabricated utilizing our synthesized
fluorophores. Among them, 3-PIMCFTPA showed the best
electroluminescence performance with maximum external quantum efficiency
(EQEmax) of 5.7 and 3.4% with Commission Internationale
d’Énclairage (CIE) coordinates of (0.17, 0.10) and (0.17,
0.02), respectively. Moreover, the 3-PIMCFTPA possesses
a pure violet emission (385 nm) with high performance, allowing the
emitter to be used to realize high-performance hybrid white OLEDs.
The 1 wt% yellow emitter-based device displayed pure white light with
a PEmax of 22.5 lm W–1, a CEmax of 25.4 cd A–1, and an EQEmax of 12.0%
with a CIE coordinate (0.33, 0.37) at 1000 cd m–2. These results of our emitters make them potential for smart displays
and lighting applications.