Authors: Ping Chen YanLian Lei Rong Liu QiaoMing Zhang Yong Zhang ZuHong Xiong
Publish Date: 2010/01/30
Volume: 53, Issue: 1, Pages: 24-29
Abstract
The DCM dye doped organic electroluminescence devices with structure of ITO/NPB/Alq3 DCM/Alq3/LiF/Al were fabricated From 15 K to room temperature the magnetic field dependent of electroluminescence MEL of devices was investigated Our observations indicated that the MEL is composed of two effects in different regimes a low field 0⩽B⩽40 mT effect and a high field B 40 mT effect For undoped devices the low field effect exhibits a rapid rising with the increasing field and the high field effect shows a slow increase and gradually saturates at room temperature For doped devices the low field rapid increase is also present whereas the high field effect displays a decrease with the increasing field The larger the injection current is the more apparent the high field decrease is In addition the doped device demonstrates less temperature dependence of the high field effect than undoped device although the undoped devices also present high field decrease of electroluminescence at low temperatures T⩽150 K Based on the energy level trapping effect due to dye doping and magnetic field modulated triplet exciton annihilation the experimental results are carefully explained
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