微腔有机电致发光器件角度依赖性的模拟与实验验证

为了分析微腔有机电致发光器件(MOLED)发光的角度依赖性,根据微腔计算公式,采用传输矩阵法进行了模拟计算,并进行了实验验证。所设计器件的结构为Glass/DBR/ITO(58 nm)/NPB(46 nm)/DPVBi(20 nm)/Alq₃(56 nm)/LiF(1 nm )/Al(150 nm)。由实验得到的电致发光(EL)谱可以观察到:随着探测角度的加大,发光峰蓝移、强度减小。与模拟得出的不同观测角度下的反射谱进行比较,发现透射峰值与EL峰值相对应。模拟分析发现,这是由于观测角不同,微腔两个反射镜的S和P偏振的反射率及反射相移不同,同时腔内光学厚度发生变化,即微腔长度变化共同作用所导致。

Simulation and Experimental Verification for The Angle Dependence of The Microcavity Organic Light Emitting Device

In order to analysize the angle dependence of the microcavity organic light emitting device(MOLED), both simulation research using transmission matrix method and experiment were carried out, based on microcavity principles and relative formations. The structure of the device was designed as Glass/DBR/ITO(58 nm)/NPB(46 nm)/DPVBi(20 nm)/Alq₃(56 nm)/LiF(1 nm)/Al(150 nm). The experimental electro-luminescence (EL) spectrum shows that the luminescence peaks blue shift and weaken down with the increasing of the detection angle. Comparing with the simulated reflection spectrum under different detection angle, it is found that the transmission peaks of the reflection spectrum correspond to the EL peaks. Further simulation analysis shows that the two reflection mirrors in the microcavity tend to have different reflection rate and different reflection phase change for S and P polarization light under different detection angle. Meanwhile, the optical thickness of the organic layer in the microcavity also changes under different emitting angle, which induces a change in the effective length of the microcavity. The reasons above all lead to the changes of the EL spectrum.