Low-Voltage, Simple-Structure, High-Efficiency p-i-n-Type Electrophosphorescent Blue Organic Light-Emitting Diodes

摘要

We present simple p-i-n structures with single-emitting and mixed emitting layers for highly efficient phosphorescent blue organic devices. Using a high-triplet-energy-hole-transporting material of 1,1-bis(4-methylphenyl)-aminophenyl-cyclohexane (TAPC) and a high-triplet-energy-electron-transporting material of 1,3,5-tris(m-pyrid-3-ylphenyl)benzene (Tm_3PyPB), the p-i-n structure has been realized by doping with MoO_3 as a p-dopant and Cs_2CO_3 as an n-dopant. A very low onset voltage of 3.0 V and a driving voltage of 4.0 V to obtain a brightness of 1000cd/m~2 are achieved in this p-i-n device configuration. A maximum external quantum efficiency of 23.9% and a power efficiency of 36.7 Im/W are reported.