High efficiency blue phosphorescent organic lighting-emitting diodes with novel anode structure

Abstract

High-efficiency blue electrophosphorescent organic light-emitting devices employing MoO₃ used as hole injection layer (HIL) and MoO₃ doped N,N-dicarbazoly-3,5-benzene (mCP) as hole transport layer (HTL) were demonstrated. The blue OLED with the novel anode structure and TAPC used as electron blocking layer show a low turn-on voltage of 2.4 V, a maximum power efficiency of 33.6 lm/W at 3.1 V and 25 lm/W with 1 000 cd/m² at 3.8 V. It is also found that the efficiency of the devices is dependent on the different EBL materials. This is may because of relationship with the charge mobility and the triplet energy level of EBL materials. The device efficiency is determined by the charge balance which plays an important role.

Keywords

OLEDs / blue phosphorescent / electron blocking layer

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