摘要
Blue phosphorescent OLEDs(Ph-OLEDs)have long faced critical challenges in efficiency,stability and brightness,which are crucial for advanced display.Herein,we introduce two novel Ir(III)emitters featuring a 3,6-di(tert-butyl)-9Hcarbazolyl(tBuCz)substituted tridentate carbene pincer ligand,significantly improving efficiency and stability.The tBuCz-m-CF3 and tBuCz-p-CF3 complexes are designed to enhance steric encumbrance and minimize exciton accumulation.These innovations lead to exceptional photoluminescence quantum yields(PLQY)of 98%and an impressive decay rate constant of 7.97×10^(5)s^(−1)in doped thin films.The Ph-OLEDs emit blue light with a peak wavelength of 485 nm and CIE coordinates of(0.175,0.446),exhibiting a peak external quantum efficiencies(EQE)of 31.62%and brightness up to 214,255 cdm^(−2).Notably,they shown minimal efficiency roll-off,retaining an EQE of 27.76%at 10,000 cdm^(−2),and 20.58%at 100,000 cdm^(−2).These consistent performances across various brightness levels represent a significant milestone for blue Ph-OLED technology.The devices also exhibit impressive stability,with an operational lifetime(LT50,the time taken for luminance to decrease by 50%)reaching 1237 h at 1000 cdm^(−2),setting new benchmarks for blue Ph-OLEDs.To enhance the color purity,hyper-OLEDs were developed with a full width at half maximum(FWHM)of 20 nm and the CIEy of 0.233,achieving an EQEm of 29.78%and LT50 of 318 h at 1000 cdm^(−2).We also fabricated the active-matrix(AM)blue Hyper-OLEDs with 400 pixels per inch to demonstrate their application in AM displays.
基金
the National Natural Science Foundation of China(grant no.:52027817)
Shenzhen Science and Technology Innovation Commission(grant no.:GJHZ20210705143204013)
Research Grant Council of Hong Kong(grant no.:CityU 11312722)lShenzhen Science and Technology Innovation Commission(grant no.:JCYJ20200109144614514)
China Postdoctoral Science Foundation(grant no:2024M761639).
