1 research outputs found
Bis-tridentate Ir(III) Phosphors and Blue Hyperphosphorescence with Suppressed Efficiency Roll-Off at High Brightness
Narrowband blue emitters are indispensable in achieving
ultrahigh-definition
OLED displays that satisfy the stringent BT 2020 standard. Hereby,
a series of bis-tridentate Ir(III) complexes bearing electron-deficient
imidazo[4,5-b]pyridin-2-ylidene carbene coordination
fragments and 2,6-diaryloxy pyridine ancillary groups were designed
and synthesized. They exhibited deep blue emission with quantum yields
of up to 89% and a radiative lifetime of 0.71 μs in the DPEPO
host matrix, indicating both the high efficiency and excellent energy
transfer process from the host to dopant. The OLED based on Irtb1 showed an emission at 468 nm with a maximum external
quantum efficiency (EQE) of 22.7%. Moreover, the hyper-OLED with Irtb1 as a sensitizer for transferring energy to terminal
emitter v-DABNA exhibited a narrowband blue emission at 472 nm and
full width at half-maximum (FWHM) of 24 nm, a maximum EQE of 23.5%,
and EQEs of 19.7, 16.1, and 12.9% at a practical brightness of 100,
1000, and 5000 cd/m2, respectively