掺杂浓度和无序对柔性有机发光二极管载流子迁移率的影响  

Effect of doping concentration and disorder on the mobility of carriers in organic light emitting diodes

作　　者：陈雨璐[1] 侯晓远[1] 岑剡[1] 

机构地区：[1]复旦大学物理系,表面物理国家重点实验室,上海200433

出　　处：《红外与毫米波学报》2011年第3期271-275,共5页Journal of Infrared and Millimeter Waves

基　　金：复旦大学“学生学术科技创新行动支持计划”(B2-19-04)

摘　　要：基于电荷分布的泊松方程和载流子输运方程,考虑最低能量非占据态和最高能量占据态的载流子态密度服从双高斯分布的模型,自洽地研究了掺杂浓度和无序对Alq3柔性有机发光二极管载流子迁移率的影响.发现掺杂浓度低于1×1020cm-3时,掺杂浓度对迁移率影响很小,迁移率几乎保持不变;当掺杂浓度大于1×1020cm-3时,载流子迁移率非线性增加,与实验结果很好一致.考虑不同无序度时,发现无序度的增加,相应的迁移率下降;低掺杂浓度下迁移率与无序度的大小关系不大,当掺杂浓度较高的时,无序度较小的材料迁移率增加较快.最终给出了柔性发光二极管器件的发光功率密度与电压关系,表明载流子浓度和无序相关的迁移率结果对制备高性能的柔性有机发光二极管具有指导意义.Based on the Poisson＇s equation of charge distribution and the transport equation of carriers,the effect of doping concentration and disordered degree on the mobility of carriers in the Alq3 flexible organic light-emitting diodes has been studied self-consistently.The density of states of the carriers was described with the double Gaussian distributions because of the energy disorders of organic molecules.It was found that the carriers＇ mobility is almost fixed with doping concentration smaller than 1×1020cm-3.The carriers＇ mobility increased nonlinearly when the doping concentration was larger than 1×1020cm-3,in well agreement with the experimental results.It was also showed that the increase of mobility as a function of doping concentration for smaller disordered degree is faster than that for larger disordered one.With low doping concentration,the disordered degree has little effect on the mobility.Finally,the doping concentration and the disorder degree dependence of the mobility is used to simulate the variations of the luminescence power density of the device with the voltage bias.It was indicated that the mobility results related to the doping concentration and the disorder is very important for developing organic LED with high performance.

关 键 词：有机发光二极管 掺杂浓度 迁移率 

分 类 号：TN312.8[电子电信—物理电子学]